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hz numbers on a 15" 2 driver (Read 39882 times)
Bob
Ex Member



hz numbers on a 15" 2 driver
04/20/06 at 22:54:33
 
I've had the housewrecker for about 3 months now, getting a good feel for it (meaning; doesn't seem as impressive as it used to.) For HT use it just doesn't seem enough, and turning the knob up just creates the horrible 'klopping' sound from drivers hitting mechanical limit. Currently using 900 watts bridged to two Dayton series II 15" drivers, magnets mounted in center chamber. Seems like these are 'accepted' drivers for this use. Has anybody got any hz or db numbers on a set up such as this? Has anyone found a different mounting arrangement achive better results for 2 drivers? I'd rather spent time/effort on my surrounds, as opposed to putting two more drivers in the enclosure, but is that what it's going to take? As a few of you know by the pictures, they won't be easy to take the existing drivers out, or rearrange. So 'playing' with it just to put them back would be aggravating. Adding won't be a problem, just $$$ not spent on surround drivers.

Any assistance is greatly appreciated.

Thanks guys,  Bob

BTW, Have moved it around the room many times (lower back hurts) I made a base that it sits on (big hole facing down) much like the sono tube arrangements with 5" of air space between it and floor.  The twin holes are firing perpendicular, behind and right of the seating position. (pics can be seen on "amp to make Daytons happy" thread page 12, reply #171.)
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« Last Edit: 04/20/06 at 23:01:07 by Bob »  
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gexter
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #1 - 04/21/06 at 13:12:02
 
I can't take the time to go back over stuff and see where your at or look at the pics right now.

But...
Changing the driver arrragement for a sure change is a complete unknown. from reading I think it depends on the characteristics of the driver to the enclosure.

I do think that your best choice is changing one of the ports. smaller and longer on the top maybe? It can't change too much because of the driver. Thats only a guess and I have not done it.

My best guess is there is not enough damping and the driver looses control. a short Xmax and good damping characteristics on the driver may go a long way.
a port change may do it, but it will change the freq.
I have thought about additional baffles in the box but never tried it.

Really Man I am just guessing from an experimenters frame of mind. No science there!
It would be the last Decware design that I would build another of at the moment..
I just finished my second DB12 and it works better than my last and restored more faith in the DB design. I still have to wait until my wife is out of the house before I give it a good HT run.

for the small footprint and for HT I would consider a TL .
That is on my wish list to build for awhile now.


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Adrian D.
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #2 - 04/21/06 at 14:42:40
 
series II have only 8mm xmax and can handle 'only' 300w. so my guess is that, with 450w to each of them they're bottoming out.
try to remove one of the lids and play some really low notes (like 10-15hz) to see if the noise you are hearing is really the drivers bottoming out or you have some leaks.
are you sure you wired them right ?
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #3 - 04/21/06 at 15:11:29
 
Sorry Adrian, I assumed the world centered around me, and that everyone had read the entire thread "amp to make Daytons happy".  ::)  :'(

My apologies, I didn't give complete information.

The Daytons I've got are the series II. They've got an xmas of 15.1, and rms watts of 350, 600 max.

They're here... http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=295-190

As far as wiring goes, they ARE out of phase since they're back to back. You know... something I just thought about, I can't remember how I wired the 2 coils on each driver. Don't you just run the wire to one set of terminals, then jump over the magnet to the other set. I'll have to pull the access cover off and check that. I may be second guessing myself.  :-/
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paulc
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #4 - 04/21/06 at 15:31:29
 
Damn Bob, it sure sounds like a wiring problem to me.

I have built three HW's and each one has been way more than my house can stand.  I use the 250watt plate amp for HT and bass traps in all corners of the room.
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paulc
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #5 - 04/21/06 at 15:34:29
 
On second thought, if your carpentry skills are anything like mine.............

The top port must be exactly centered!  All seams sealed tight with liquid nails or similar.
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #6 - 04/21/06 at 15:42:50
 
paulc, I want to tell my boss I've got to go home for an emergency to check my wiring.  

As far as woodworking skills, at the risk of sounding arrogent, I would say better than average. (better than spelling) 9 ounces of Gorilla glue was used in the construction. I would say it could be used as a submarine if it werent for the 3 big holes in it.  ;D

I'm really worring about the wiring to the individual voice coils. I know the drivers ARE out of phase though.

If your rockin' the house with 250watts, somethings wrong with mine. - and it IS built to spec.

Bob
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DirtDawg
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #7 - 04/21/06 at 16:52:52
 
[quote author=Bob  link=1145573673/0#6 date=1145630570]...........
I'm really worring about the wiring to the individual voice coils. I know the drivers ARE out of phase though.

If your rockin' the house with 250watts, somethings wrong with mine. - and it IS built to spec.

Bob [/quote]

Bob,

I'm trying to work my way back over the other thread for something we all missed and I'm a little confused which driver you have. Series II and Dual Voice Coil are distinctly different and I hope you got the DVC which has double the Xmax.

Also, the total impedance that the amp sees needs to be within spec or it can clip very easily and that can sound like a "KLOP" inside a big box, but so can bottoming your drivers.

Are you still using the shakers? I remember they had a problem, but what's the latest?

Verify the wiring and the impedance.

One other question ... why did you turn the box upside down?
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« Last Edit: 04/21/06 at 16:55:08 by DirtDawg »  
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #8 - 04/21/06 at 17:58:58
 
I'M SORRY GUYS. I've got the series II's.  Adrian, you read correctly. Sorry, my head was in my butt.
Here's what I got...

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-130&CFID=4954...

DD, using the shakers occationally. I mounted them in the bottom of the seat cushion. Just under a sensitive bodily area. They need to be moved to the back I think. When they are turned up, it vibrates parts of my innards that don't need to be vibrated.

Pics of the shakers mounted are here...

http://community.webshots.com/photo/549522535/2690067230085868784FhZCXU

Bob
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Adrian D.
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #9 - 04/21/06 at 18:08:14
 
bob, i actually read the topic before i posted. YOU said you got the series II. you must wire them in paralel and one out of phase. check that before trying anyting else.
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #10 - 04/21/06 at 18:15:29
 
Yes, Adrian, you are correct. I've second guessed myself so much, I could'nt even remember what I bought. The are out of phase. Inside the box I "Y"ed the wires, (soldered them with heat shrink) then ran + to +, - to - to one driver, and + to -, and - to + to the other driver. That's ok isn't it?

Bob
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J_Rock
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #11 - 04/21/06 at 22:28:47
 
wiring is correct for four ohms with one out of phase.

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J_Rock
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #12 - 04/21/06 at 22:43:16
 
What do you have for wiring, are the 2 subs on one channel of the legion amp?

If so, You might want to look into a sperate amp for your shakers.

Legion gives these specs.
225 x 2 at 8ohm
900 x 1 at 4ohm (mono)

I would parallel your subs and bridge them to your amp, works out to 450 watts a sub.  a sub on each channel gives you 225watts a sub, both subs on one channel gives you 200 a sub.

Not sure if those are RMS or just watts.

In any case, 450 a sub will make them much louder, plus you will be able to re-wire them to make sure the wiring is correct. (I assume it is already anyways.)

Abotu the knocking, that amp is defineatly not overpowering your subs, it may be clipping.

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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #13 - 04/21/06 at 23:11:33
 
J rock, You first thought is correct. They are parallel, bridged, mono. Tha amp has a green led for each channel, they start illuminating when things start getting loud. obviously they illuminate together. It has a red clipping light for each channel, and yes I have seen the "danger" lights which also illuminate together. I've heard the klopping with no clipping lights, and have seen the lights with some 'bad noise' but no klopping. I did line upper, and lower chambers with 1/2" automotive carpet pad. Really mad no audible difference.

DD, to answer your question, I flipped it upside, it just sounds better with the 2 ports on top.  color me silly.

Bob
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J_Rock
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #14 - 04/22/06 at 00:18:45
 
perhaps the amp is not cliping, but the source is.  

How do you have the system wired?

If the amp is indeed fed by a source unit (i.e. reciever):
1. Turn the sub amp all the way down.
2. Place music in source and turn it up till you hear audible distortion, turn it down a bit. (Remember this volume as max volume)
3. With music still cranked, turn sub up until it sounds good, or you hear distortion.

Now your gain is dialed in for max output without distortion.
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John in CR
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #15 - 04/22/06 at 03:52:27
 
Bob bob bob bob bob,

I don't know why people keep trying the Daytons in the HWK.
Few have success.

The HWK is more of a club cab than an HT cab.  This is because of the port tuning.  Just plug the top and bottom chambers into a 6th order bandpass cab to see what I mean.  The center chamber has the magical quality of smoothing an otherwise double peaked response, but it doesn't change the tuning of the vented chambers.

That banging noise is definitely the drivers hitting the back plate.  This is happening because your sending material below tuning, resulting in loss of cone control.  Since you have 8mm of Xmax and a mechanical limit of only 9.2mm , you get bang bang bang with low frequency content.

The first thing to try is a different tuning.  Take the top driver out and play just the bottom one.  This will greatly lower the tuning of the top chamber.  Maybe it will sound ok to you for HT.  If that works better, then just mount the 2nd driver clamshelled to the bottom one.  If that still doesn't cut it, try taking off the bottom cap and listen to it laying on it's side.  That's not too far from the recommended vented cab for the driver.
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HT-EXT
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #16 - 04/26/06 at 17:24:31
 
No offense to anyone but I have Series II in both my HWK15s and have been a fan of Daytons ever since. I am not sure what to tell you BOB. It sounds like everthing is hooked up right and with IIs, plus 450w+, I don't think you should have any problem going low or loud. One HWK with two Daytons(hooked up the same as you) with about 300w will hit between 115db to 120db(3ft away) and rolls off hard around 28Hz to 25Hz depending on the material being played. Understand this is my set up and almost every set up is different. I also use the Ultrabass Pro EX1200(Behringer) if I need that extra punch or low,low bass. Besides sometimes when the whiskey is flowing my system doesn't sound loud enough for me either. Just keep on "BOOMING"  and you will figure out what you like the best.   HT-EXT
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« Last Edit: 04/28/06 at 17:27:33 by Joe_Eaton »  
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #17 - 04/26/06 at 20:41:59
 
Yea, my intention last week was to drag the big S.O.B. back into the workshop to increase the WAF visually, and increase my "acceptance factor" audibly.

Well, I got it into the workshop had it painted on the exterior, and lined inside and threw my back out flipping the damn thing back upright. So I put it back in it's home, fired it up, and drank some feel better juice for my lower back. Still haven't recovered.  >:(  Didn't notice ant difference lining top and bottom chambers with padding either. BUT, the wife says it looks prettier now.  >:( THAT was a kick in the balls.  :-X Cry All that work, no audible difference, bad back, and IT LOOKS PRETTY. ARRGG.


Liken' the looks of that Behringer HT-EXT

Bob
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Jet-Lee
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #18 - 04/27/06 at 12:59:32
 
Dumb question, but what does 'WAF' stand for?! It's been driving me nuts trying to figure out.

All I've found is Women in the Air Force, What A Fag, and somethin' else......None of which make sense in the context in which it's used on these forums.
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« Last Edit: 04/27/06 at 13:01:43 by Jet-Lee »  
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DirtDawg
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #19 - 04/27/06 at 13:22:53
 
WAF? Also SAF and SOAF, but there are others. It's a perfect question from a newlywed. You will soon come to appreciate the subtleties of WAF issues.

F=Factor
A=Acceptance
W-Wife
S=Spouse or Significant
O=Other

There are other ways to describe the same complication, but that's the idea.
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« Last Edit: 04/27/06 at 13:32:58 by DirtDawg »  
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Wreckinthehouse
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #20 - 04/27/06 at 22:37:39
 
I'm not sure what the Dayton's or other speakers cost, but when I spoke to Steve, he told me that the HW's were designed for Black Widows. Why fight it? Just buck up! Grin
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #21 - 04/27/06 at 22:50:17
 
Well Wreckinthehouse, here's what Steve wrote in the Housewrecker section....

"Using musical instrument woofers (ex. PEAVEY BLACK WIDOW) you get tight full accurate bass from 200 down to 40 HZ. Using subwoofers you get big warm full bass that can on command create Subsonic pressures lower than 20 cycles".

The reason I picked the Daytons is two fold.. #1, Steve said a SUBwoofer driver goes 20hz lower than the Black Widow, and #2, general consenses was the Dayton was a good choice (being a Sub-driver). But the big factor for me was the word 'subsonic'.

See what I mean?...  ;)

Bob

p.s. By the way, the Daytons were $90 each. I never checked on the Black Widow.
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« Last Edit: 04/27/06 at 22:52:31 by Bob »  
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #22 - 04/27/06 at 22:54:36
 
Checked Parts Express, $175 each if this is them...

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=294-303

Bob
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Wreckinthehouse
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #23 - 04/27/06 at 23:35:09
 
The Black widows are about 150.00 each, and if you blow one you just unbolt it and change the basket. I, like you have tried other woofers but i always put the Peaveys back in. Subsonic?, Id have to hear a major difference to replace my woofers, but the jobs that i play at, it buckles the walls. It's pretty embarassing when the pictures in the halls start hitting the floor, but hey thats what it,s all about
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #24 - 04/28/06 at 12:44:19
 
Wreckin', how many drivers do you have installed, and how are they positioned?

Bob
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HT-EXT
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #25 - 04/28/06 at 15:44:19
 
What up BOB? Have you ever consider laying the HWK on its side. I have one HWK15 standing up and one laying on its side with the top port firing at a concert wall. The one laying down seems to play lower and louder but that could be because of the wall. The Series II are almost "dead on" with the specs provided by Steve that is why I pick the Daytons. Have you every consider building the WO36 for HT? I "eyeballed" your pics and with a WO36 in front and the HWK behind would be a balistic or SUBsonic combo. Of course I might be throwing more trouble at you with another subwoofer in the room.     HT-EXT
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J_Rock
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #26 - 04/28/06 at 16:21:16
 
rewire the drivers so they get more power for a little bit.

I am betting they just don't have th eumph they want.
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John in CR
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #27 - 04/28/06 at 18:25:46
 
Bob,

Isn't this for your HT ?  The HWK is not an HT subwoofer.  It is a great club cab though.  It simply doesn't do low enough to be good for HT.  As stated above, it was designed to roll off below 40hz.  It doesn't really matter what driver you put in them, that doesn't change the tuning.  You can try increasing the top chamber by installing your drivers only on the bottom baffle.  Save your back and just take the top driver out and give it a listen.  I don't like mine like that, but who knows.  It will definitely give you more bottom end extension.
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Wreckinthehouse
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #28 - 04/28/06 at 21:04:29
 
I have the magnets in the center chamber. Like John in CR stated, if you remove the upper woofer, you will get much lower sound but less control at high volume. The HW will also be much more efficient. Almost forgot your question, I have two woofers per HW.
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #29 - 04/28/06 at 22:09:31
 
HT-EXT, The first location for the sub was laying on it's side, directly between the front surrounds with the 2 bottom ports facing towards me (first), straight up, then away from me. (now it's behind and right on me).
Yes I have checked out the WO (would be great to be able to find sub plans for existing Daytons) but havn't gone any further, wanted to 'improve' the HWK for my use, -- see response to John below..

J-Rock, Rewire? not sure how I could change existing circuit?? They are already bridged and parallel, 900 watts (amp knob is not even 1/4 of the way up and get the 'klopping' Cry )

John, John, John, John,  :D  Yes it is for HT(mainly),  music and gaming are a tie for 40% of intended use. I did my best to pretent you didn't say that the first time you said it. Have'nt been able to forget, it keeps haunting me. Now you've said it twice, I can't hide any more. Ok, I'll give the HWK another tweek or two before I start the 'subwoofer plan search' again. (That's how I found Decware in the first place) I'll remove the top driver and see how that does. But while I have you 'on the phone' what would be your idea of a good - to - very good HT sub? PLANS, not prebuilt. Now remember I'd like to use the Daytons again if possible, I mentioned in another thread I spent $2,200 for decking material (It's her turn to spend money since HT is "done enough" {her words Roll Eyes}, I get to be the one to build) So money IS an issue at this point.

Wreckinthehouse, (2) per sub, hmmm.

Bob

Hey John, your a HT guy, have you ever heard of an adaptor for component video to DVI-I, or one from S-video to component, or S-video to DVI-I?
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J_Rock
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #30 - 04/28/06 at 22:29:42
 
the klopping is coming from your source then, especially at 1/4 volume

turn the bas down on your source and crank the sub amp's gain up.

Those subs will not bottom out and klop at that wattage, the amp I doubt could ever bottom them out.

The klopping therefore has to be a loose board, or your source clipping.  I assume your construction is plenty strong, so clipping will do it.

The box's intended use will nto fource it to handle less power or klop.
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #31 - 04/28/06 at 23:00:45
 
You know J,   John had some good points about using the proper equipment for it's intended purpose, which I havn't. But you may have a good point there about maxing it out on such a low setting. I've played with receiver bass vs. amp setting, but will play with that again. Both before and after removing top driver. Two good 'points of reference' when it klops the worst, #1 Finding Nemo, when little girl is banging on aquarium, and #2 Star Wars III opening sequence with two fighters flying between larger ships. That opening sequence has two good lenthy LFE points that the HWK HATES! Basically any changes I make to the system, those are my reference points I check back with. Don't like "mid movie surprises" when I'm lost in another world, everything is great, and the F---ER starts bangin' again!  >:( Angry I can feel my blood boil.

Still open to suggestions on different DIY enclosure. Anybody wanna buy a HWK? Actually, I may step up and give it away if a replacement is found. (60ndown, your my hero) NO SHIPPING INCLUDED, I'm not that much of a man. $$$$$$$$

Bob

p.s. This happened on the same settings with 2 different Legion amps
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« Last Edit: 04/28/06 at 23:01:34 by Bob »  
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J_Rock
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #32 - 04/28/06 at 23:26:26
 
Well, if it only klops at the very low frequencies, then it may be driver related.  I read it that it klops whenever tyou crank it, music movies etc..
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #33 - 04/29/06 at 00:57:58
 
Bob,

It's not the amp.  It's not the drivers.  It's the alignment, which on the low end is tuned somewhere in the mid 30's.

Your problem will come into play with virtually any vented design, whether it's BR, horn, or in the case of the HWK, bandpass.  That is your driver will go into over-excursion with very little power when you play frequencies below tuning.  In finding Nemo, you get a very strong signal down in the low teens and you're going to damage your drivers trying to play that with a normal HWK.

In all likelihood you have enough horsepower to get what you want with those 2 15" drivers.  With my pair of Tempests, which are comparable to your Daytons, Dan Wiggins of Adire Audio recommended to me a 6th order bandpass box (that's what a HWK is btw), but with much larger dimensions.  The dimensions were 56.6L for the top chamber and 340L for the bottom chamber.  Each was vented with a 4" diameter, 17" long vent with big flares at both ends.  200W gets you to 110db in room from 11-40hz.  Be careful not to fall out of your chair when Darla taps on that fish tank!  If interested, check out post#5 here for what would be a HWK on steriods:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=59473&highligh...

A much smaller alternative is going with small sealed boxes and using a Linkwitz transform to flatten the response from the lowest level you want to play.  You need the maximum amp power that your drivers can handle.  Then you say eg "I want extension to 10hz".  With your amp and driver max'd out at 10hz you do the Linkwitz transform above that which essentially whacks off the extra output potential as frequency increases, to net you a flat response.  It's kind of like building a car that is geared for mountain climbing, then driving it down the highway just in case there's a mountain to climb (Darla tapping on the glass).  There's no way this method will get you to 110db at 11hz, but with dual 15's it will probably get you to satisfying levels.

For either method, you could incorporate your existing HWK into the design, so that wood doesn't go to waste.

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« Last Edit: 04/29/06 at 01:00:25 by John in CR »  
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Mr Content
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #34 - 04/29/06 at 12:57:43
 
Bob Have a look at this site. You could get 10hz in a small cube, but you will need to get new drivers, and the amp to go with it.

Mr C

http://www.rythmikaudio.com/index.htm
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #35 - 05/01/06 at 12:47:48
 
John, I spent a few hours playing with WinISD alpha (not pro) on the numbers given by Dan Wiggins. The final result was a bizarre graph like I've never seen before. The line looks like the financial earnings of a company VERY QUICKLY going it the toilet. I'm not sure how you guys get those cool looking WinISD charts to display here? But the line starts on the left at -11.5db @ 10hz, and quickly drops to -30db @ 60hz. Could this be correct? Box numbers obviously taken from Dan, the driver numbers inserted from PartsExpress.

Intriquing the small box you mentioned, when you say small sealed boxes, and still use the HWK, are you talking about getting out the circular saw and cutting the top and bottom chambers away from the center, and sealing the holes?

Mr. C, I like your idea, but not an option financially at this point. Wood is cheap, I'll build a few boxes if I need to, but can't be buying drivers and amps right now.

Bob
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Mr Content
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Re: hz numbers on a 15" 2 driver
Reply #36 - 05/01/06 at 12:59:53
 
Bob sell what you have got to finance it. Grin

Mr C
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #37 - 05/01/06 at 13:11:54
 
Another good idea C.  I'll find out how much it wieghs, then call FedEx for shipping price to Australia, what was you address again??  :-*

BTW, it's painted gray now, to match my walls, but it can change colors very easily, just tell me what color you want.  :D

Seriously, I can't believe anybody would pay much for it, especially since my salespitch hasn't been very positive.

Bob
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DirtDawg
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Re: hz numbers on a 15" 2 driver
Reply #38 - 05/01/06 at 13:14:34
 
Bob,

You are right. If you use a super low 6th order alignment, you will lose efficiency. The reason it works is many drivers have power handling capacity that makes the efficiency less of an issue. You should actually see 2 humps in the response with a 6th order enclosure. One around the 10Hz range and another around 28Hz, if I can remember  correctly, using Dan Wiggins' design. The isobaric chamber should smooth out some of the unevenness of the alignment. BUT, like John pointed out, it will support your drivers at a much lower frequency with Dan's dimensions.

You might also try the driver placement that John mentioned for your current box with the drivers in the smallest chamber, and close off one of the two ports in that chamber.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #39 - 05/01/06 at 13:41:27
 
Ok, just to make sure I've got this correct....

Step #1 Remove both drivers.
Step #2 Install both drivers clamshelled on lower baffle. (One magnet in lower chamber, one in center chamber)
Step #3 Seal one of the two bottom ports, leave large top port alone.

Is this correct?

Bob
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trashfire
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Re: hz numbers on a 15" 2 driver
Reply #40 - 05/01/06 at 22:58:48
 
Bob,
I can totally understand your frustration with the HWK and it crapping out at ultra mega low frequencies.  I had the same issue and it bugged the crap out of me.  

I'm in no way affiliated with, financially interested in or otherwise have anything to gain by recommending this but take at look at www.billfitzmaurice.com specifically the TableTuba.  I know you said you didn't want to buy new drivers but the driver for that enclosure is $40 shipped.  

I replaced my HWK with dual 15"s and 1500W with a tabletuba loaded with a cheap 8 and 150W and it blows it away.  The efficiency of a folded horn is incredible.  The proof for me was Master & Commander.  The HWK just flat out could not keep up with the cannon fights but the tabletuba rumbles ALL the way down.  It's quick thanks to the small driver but still unbelievable low and loud.

You can build it with 2 sheets of 1/2" MDF or ply so the wood costs are really low.  It's a bit intimidating to build because of all the angles but once you get into it, it's not that bad.  I built mine in a weekend.  Exterior dimensions are about 30x30x16.  

Not having built a WO or WO32 yet, I cannot do an apples to apples comparison but I can compare the TT against the HWK and the TT takes it hands down.  Add the fact that the TT is an 8" against two 15"s & 10x the power just adds to the margin of victory.

Hope it helps,
Chris
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #41 - 05/01/06 at 23:57:27
 
Bob,

It sounds like the sim you ran was correct.  In the thread where Dan made the recommendation I was soliciting advice to best handle 25hz and down using 2 15" Tempests.  He said that cab should get 110db in room from 11hz to 40hz with 200 watts, so 10db of room gain down at 11hz sounds about right and output would fall off rapidly above 40hz.

Now that you know how to work WinISD, see what is possible with your existing box.  In modelling, leave the top chamber alone and move the other driver up there and don't forget to factor in the 3L or so volume decrease.  That may be low enough tuning for your higher tuned chamber.  Then play around with port lengths for the other chamber (including the center chamber in the volume).  You may have enough volume there to get down close to 20hz without too much port velocity.  Forget about the teens, because that really does take 300L+.  I'm not sure what kind of space you have, but you might even be able to get away with just adding on to your current HWK cab and getting output down to where you want for HT.


Chris,
While I've heard that Bill's designs were pretty good, those are all for music and as far as HT and bottom end extension goes, I could build a 2ft3 box for a single shiva that would laugh at what any small box horn could do for HT.
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« Last Edit: 05/02/06 at 00:01:05 by John in CR »  
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trashfire
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Re: hz numbers on a 15" 2 driver
Reply #42 - 05/02/06 at 04:09:58
 
The tabletuba was designed as a home subwoofer for theater and musical applications.  It has a 13 ft path which gives it a very low fc which lends itself well to theater applications.  I can personally attest to it's excellent performance in HT.

If the small box horn (which does extend even lower than the $2k velodyne 12 I originally compared the HWK to) doesn't float your boat, build a bigger one.  The Tuba36 loaded with a 12" or 15" driver would absolutely spank a shiva in any enclosure.  The verticle baffle 15" version extends to like 15hz at 95db 1w/1m. Even if it falls flat on it's face and rolls off at 18db below that, you're still getting ludicrous output to bowel loosening frequencies without sacrificing the higher bass above 40 and 50hz.

There's a reason people use these things to entertain thousands of people at a time.  You're not going to find a Shiva up on stage at the next concert you go to.  I'd really like to see a 2 cube box with a single 12 extend below the mid-teens with an effectively flat response on 150W.  AND still do it for under $100 total build cost (excl amp but incl driver).  I just don't see it happening.

If nothing else, it's worth a try to learn.  I was looking at getting some stroker 15's or 18's for my theater when I found the folded horn design.  I've become enamored with the horn theory and learned quite a bit about what all those TS numbers mean and how horns work.  That's what this is really all about.  It's also a blast to see the look on people's faces when 1 tiny teeny little worthless 8 shakes their ass from 15 feet away.  Check it out, read the forums and decide for yourself.  

I personally will never go back to direct radiators for my sub needs.  That's my opinion and we know opinions are like @$$holes, everyone has one and they usually stink.  I'm not trying to put down steve & prop up bill or vice versa.  I just think in my situation which sounds similar to Bobs, I found a better mouse trap and built it.

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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #43 - 05/02/06 at 07:03:50
 
Well Trashfire that's big talk.  Why don't you send your little over compromised horn a 15hz sine wave and 50-100 watts for a while before you go around bragging about how great an HT sub it is.  I'm sure it does fine above 25hz, but subsonic it's going to be excursion limited rather quickly.

I'm sure that Bob would rather do it right this time instead of just building another stepping stone in route to getting the performance he wants.  He's already got drivers that can get him where he wants.  He has an amp that will do it.  He even has a good portion of the box already built if he plans things well with a very simple build to finish it up, but of course my opinion stinks.
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Mr Content
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Re: hz numbers on a 15" 2 driver
Reply #44 - 05/02/06 at 08:35:42
 
[quote author=Bob  link=1145573673/30#38 date=1146485514]Another good idea C.  I'll find out how much it wieghs, then call FedEx for shipping price to Australia, what was you address again??  :-*

BTW, it's painted gray now, to match my walls, but it can change colors very easily, just tell me what color you want.  :D

Seriously, I can't believe anybody would pay much for it, especially since my salespitch hasn't been very positive.

Bob [/quote]

Hmmmm..... I think I might have enough MDF, HDF, PLY. Solid Timber here already Bob, but thank for thinking of me, I appriceat it. Cheesy  ;D

Mr C
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #45 - 05/02/06 at 12:38:01
 
John, you made me laugh, "I know how to USE WinIsd"  :-/. No, I can't USE it, at this point in my life, I can input numbers and look at the pretty line I've created. Just for fun I can play with the signal generator and attempt to blow my poor little PC speakers. But as far as using it intellegently, no. I've clicked on things that look like something I want to do, but it tells me this version can't perform that task. I've checked for updates but apparently this is the newest version. I need to check into WinISD pro I think. But it may do nothing more than provide me with more buttons to click that do something I don't recognize.  ::)

Slow learning curve with all going on in life. Beginning to think I'd rather be a lazy mooch and build from plans. (I've learned over the years I rather be the creator, than the designer) I feel like I need to have a night course at a local college to learn what all this stuff really 'means'.

As far how much room I've got to play with, Plenty. The area between the seating and back wall is about 11' wide X 6' deep. +++++ And for those of you that think I need a couple of Imperials, the rooms not that big. I've thought about it.+++++

trashfire and John, I'm enjoying the frendly discusion, please continue. I like to learn from other people. Do you guys think the difference of opinion may be the difference in reference points? Example; The pilot of an old B-29 bomber may think his is the cats meow, it does everything he could ever need or want. But, since he's never piloted a B-52, which is sooo much more capable, he's got no refence point, no idea that such a better piece of equipment exists.

Mr. C, glad to here your doing ok in the lumber department. Just say the word and it could be yours! Well, maybe not just yet, we'll see how it turns out the next time it comes back through the doors of the "Bob the Builder" workshop when John gets finished with me.  ;)

Bob
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trashfire
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Re: hz numbers on a 15" 2 driver
Reply #46 - 05/02/06 at 14:42:07
 
How do you know I haven't sent it a sine wave sweep?  I wouldn't be lauding it's worth unless i've put it through it's paces.  The driver has an xmax of 16mm so there's plenty of excursion.  My front window resonates at 42Hz, the side ones at 35, the large painting in the hallway (more likely the wall itself) around 25, the dog gets mad around 18, etc etc.  If you want or need more, you can put an Eminence 10 (HL10) in it, throw 300 watts at it and probably do damage to your hearing, your relationships with your neighbors and your criminal record.

If you want a 1 note wonder, build a giant 6th order BP. It's going to sound like crap but it'll be loud.  Have fun trying to blend it with your 3 other tuned wonders and then your mains to get the full audio spectrum.   A Bandpass is just that.  It's a "lets focus our attention at a couple frequences and play the hell out of them and ignore the rest".  What good really is the movie going experience if a girl banging on the aquarium massages your back while the explosion of a bus allows you to hear the phone ringing in the next room?  You need to be able to play way down low for today's LFE tracks but still blend it well with the frequencies in the 40 to 80/90/120 range (basically however far down your mains will play).

I'm building a Tuba36 right now.  I should be done in a couple weeks and I'll have a comparison to that as well.  I'm fairly confident I'll find it blows everything including the TT away.  That the TT can handily defeat the HWK, I can only imagine the orders of magnitude that a Tuba36 would outperform a HWK and do it across a MUCH wider range.

You may be right Bob on the reference point issue.  I've spent a good number of hours and days reading up on enclosures and theories behind them.  I'm in no way claiming to be an expert and anywhere near the knowledge or experience of most of this board and certainly Steve & Bill but I know what I like.  The theory behind horns just makes sense.  A horn (as it's been explained to me) is basically an acoustic leverage device.  A small driver exciting alot of air at one end will excite a large amount of air at the other end of the horn thanks to an exponentially expanding throat.  That's why you don't need a huge driver and kilowatts of power for huge sound.  The imperial cabinet is a type of horn and you see how much everybody here loves the bloody things.  I just don't have the room or I'd probably build one or two.

What I've found in practice supports my opinion that horns rule, a good sealed box will work if you can't have a horn, vented if you're desparate and bandpass if you're only concerned about SPL drag racing.  
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Adrian D.
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Re: hz numbers on a 15" 2 driver
Reply #47 - 05/02/06 at 14:57:14
 
i say both john and chris should build the best they can and send it to bob for a comparison.  :D
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« Last Edit: 05/02/06 at 15:03:11 by adi_ro »  
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #48 - 05/02/06 at 15:41:33
 
Every few months someone brings up the tuba designs and I can't remember why I didn't like them so I check the site again and remember very quickly.

Even on the largest tuba, lf rolloff starts around 40 hz and is down 10 db or more by 20 and still dropping hard, measured for corner response.  You would have to stack at least one more, and probably 3 more, to get close to flat down to 20.

There are much smaller, albeit less sensitive ways to do this.

I've read reports of the WO going flat to 27.

If you want a traditional horn flat down to 15 the mouth is going to be roughly the size of the cross sectional area of your listening room.
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #49 - 05/02/06 at 16:00:09
 
Once again Trashfire, if your little overcompromised horn sub is so good, why are you building a different one to replace it?  I'm not knocking your TT.  It looks like a real performer for its size.  

I'm just trying to help Bob do something with what he already has.  An hour or so, and a sheet of plywood and he can find out if it's a fit for him.  He wouldn't even need to change anything that he already has.  The wiring, drivers, etc can all stay in place.  Just take off the bottom cap, add 4 rectangular pieces of plywood to extend the bottom chamber and cover the existing ports, add some shelf braces and a port, and the old bottom cap now becomes an end insert instead of a cap.  

Now that I'm thinking how easy this would be, I may have to dust off my old HWK12 and do a HWKenstein conversion on it.  I already have the drivers, wood, and flared ports required.  Plus it would satisfy my curiosity regarding the effect of Steve's twist on 6th order bandpass (the large isobaric air cushion), using similar dimensions recommended by Dan Wiggins for an over the top low tuned sub.
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« Last Edit: 05/02/06 at 16:22:18 by John in CR »  
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trashfire
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Re: hz numbers on a 15" 2 driver
Reply #50 - 05/02/06 at 17:47:20
 
With Adrian's comment, I can't help but think of the old schoolyard days... "fight fight fight fight!!"  :)  I think if John weren't in CR and I weren't in FL and Bob wasn't wherever he's located, we probably would!  :)

Extending the HWK, aside from looking kind of ghetto, is still going to suffer from the same problem of being a 1 or maybe 2 note wonder.  Increasing the chamber size is going to change the tuning, obviously, but it won't rectify the issue.  

I'm not building the Tuba36 to replace the TT, I'm building it as an experiment and for a different sound system.  Bassboy mentioned it rolling off at 40Hz and down 10db at 20 hz and it keeps going. The vertical baffle is maybe 10db down at 15 hz and not down quite so sharply.  What's not mentioned is the scale.  10db down from 130db is still 120db.  A little EQ will flatten that out very nicely.  

Bassboy, what are the smaller ways to accomplish the response we're talking about?  I'd like to read up on them if you have some links.

Bob, try the extension.  We're all in this to learn and debate (on occasion) our ideas & opinions.  If it works for you, wonderful. That knowledge will help the next guy who comes along with a similar issue.  If not, at least we know, so same deal.  

John, you keep mentioning the TT's size.  It's not really that small. The enclosure is 30X30X16.  That's about the size of a WO or WO32 give or take.  I've got some woofers intended to go into a WO and I will be building one in my quest for the ultimate sub.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #51 - 05/02/06 at 19:06:15
 
John, I was with ya on the construction for awhile there until you said; "the bottom would be an insert instead of a cap", it seems so obvious the bottom plate would be relocated, but since you mentioned it, makes me wonder if I missed something there.  I understand we're talking adding hieght to the enclosure, but are you saying attach the extra wood to the SIDES of the box extending lower? Then I see how the cap plate would fit inside.  What kind of numbers we talking here for extra box length, port length and diameter? WinISD program is at home, I'm not. Wanted to get started on construction in my head. ( besides, like I said, I know just enough about the software program to ruin some wood.  ::) )

I'd almost be willing to build the TT and start my collection of subs to fill the hz/db gaps if needed. I've got an older Sony stereo receiver that does 100wpc I could use. But would rather alter what I've got.

Bob
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« Last Edit: 05/02/06 at 19:53:18 by Bob »  
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #52 - 05/02/06 at 19:22:20
 
Trashfire,

Now you are just pulling numbers from the air.  Bassboy is probably correct that those predicted responses on Bill's site are with corner loading.  Plus all of the ones I looked at cut off at 20hz.  120db at 15hz, come on get real, 90-95db max at 15hz, maybe.  You really need to talk to Bill instead of just making things up off the top of your head.

There are no links to the kind of stuff you are talking about because it doesn't exist.  Sealed with Linkwitz transform, big vented box, and giant horns are how you get down really low.

While a 6th order bandpass can be a 2 noter, it doesn't have to be.  I built several HWK 12's for friends and they all worked fine with reasonably flat response from 40-100hz.  All I want is the same octave and a half, but starting as close to 10hz as possible.
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trashfire
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Re: hz numbers on a 15" 2 driver
Reply #53 - 05/03/06 at 01:29:15
 
Additional charts are provided in the plans and have been discussed in the forums.  The 120db figure is obviously not 1w/1m but what someone measured, not predicted responses.  These figures also do not apply to the TT, I was referencing the T36 if that wasn't clear.  

There's no point to arguing with imagined numbers. It serves no greater good.  Any figures I quote are going to be measured responses.

If all you care about is an octave and a half, BP is right up your alley and I wish you all the enjoyment it can provide you.  Audio is too much a subjective topic to have a right and wrong answer.  I want as many freq's as I can get to sound the same.  That's just me.  

For my purposes, my overcompromised horn is a better performer than the HWK ever could be.  I'm not going to try to shove my beliefs down anyones throat and tell them what they should like.  

My opinion, and it's just that, the best solution is to ditch the HWK and build a horn enclosure.  If that doesn't work due to desires/sunk costs/taste/etc then disregard.  

Unfortunately I do not have the knowledge of bandpass enclosures to offer any advice on modifying the HWK so I don't have anything else positive to contribute.  
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #54 - 05/03/06 at 05:30:58
 
Trashfire,

Don't get me wrong.  I firmly believe that horn bass and OB bass are the 2 best sounding ways to make bass.  It's just that neither is practical once you start talking about real HT extension and getting the performance level where you never feel the need to build yet another sub.  If subsonic extension was reasonably achieveable using horn loaded enclosures, then no one would build anything else.

If anything near 120db at 15hz was possible from a 36"x36"x20" single 15" horn or even the 36" cube dual 15" Tuba 36, I'd start building tomorrow.  Just filter or EQ the higher response down to flat and you'd have the ultimate subwoofer for music and HT.  Unfortunately, the laws of physics get in the way.
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Adrian D.
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Re: hz numbers on a 15" 2 driver
Reply #55 - 05/03/06 at 12:30:42
 
problems solved with this
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« Last Edit: 05/03/06 at 12:40:18 by adi_ro »  
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #56 - 05/03/06 at 13:35:50
 
Dude, are kiddin' me? I guess that would fix it.  ;D I could fully load a HWK for just over $2,100.   Cry That's friggin' dandy.  :-X

Ok, back to reality...... (Adrian, got a couple grand I can bum?)

JOHN HELP... I "played" with WinISD for 'calculate box dimentions', and it said this version can't perform this task. WTF?!
You got me all worked up and exited now John.

Bob
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« Last Edit: 05/03/06 at 13:36:16 by Bob »  
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Adrian D.
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Re: hz numbers on a 15" 2 driver
Reply #57 - 05/03/06 at 14:10:25
 
Bob, if i had 1k$ i'd jump on an rl-s 15 and a 2kw pa amp. but i don't have that money.  :D
sure i'd lend you a couple grand.
it's too much xmax (38.5mm) for the hwk. it would blow up  :D
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« Last Edit: 05/03/06 at 14:10:41 by adi_ro »  
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Adrian D.
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Re: hz numbers on a 15" 2 driver
Reply #58 - 05/03/06 at 14:21:05
 
Bob, you could try to simulate in winisd a vented box and choose the EBS alignment. -3dB version i guess. ebs is a pretty good choice for ht.
another idea would be to look into TLs.
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« Last Edit: 05/03/06 at 14:21:47 by adi_ro »  
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #59 - 05/03/06 at 14:48:15
 
Well Adrian the thing is, I've got this house wreckin' beast in my room that I'd like to tweek. Sure there's some pretty sexy looking units out there that have more than peaked my interest (grass is always greener) but I was trying to stay monogomous [sp?] if you know what I mean. Would love to have the ability to have several to swap/play with, I've got plenty of space, but it's not possible.

EBS? have heard of it, forgot what it means. Please refresh my memory...

Bob
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« Last Edit: 05/03/06 at 14:49:57 by Bob »  
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #60 - 05/03/06 at 14:52:36
 
Guys,

Don't get fooled by hype.  That sound splinter thing has the specs of a piece of junk,  primarily Qts .95, Fs 25.5, and SPL 82db.  Plus I'm sure that Xmax is point to point, so the true Xmax is 18mm.  They're pretty and would make nice OB or IB woofers, but that's about it.  Their own graphs show a steep roll off below 30hz even with the 10cuft enclosure.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #61 - 05/03/06 at 14:57:39
 
John are you teasing me?

Bob
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Adrian D.
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Re: hz numbers on a 15" 2 driver
Reply #62 - 05/03/06 at 15:07:14
 
whoops. john, the rl-s has a Klippel verified xmax of 38.5 mm (one way xmax, so 3inch peak-to-peak). it supposedly broke the measuring device when the guys at tc sounds played with it. qts is that high, because the BL is constant on the whole stroke . on any sub the qts varies across the stroke because bl varies across the stroke. xbl^2 is nothing compared to that when it comes to linearity.
info on the topology used by the rl-s : http://www.soundsolutionsaudio.com/forum/index.php?showtopic=2748
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« Last Edit: 05/03/06 at 15:11:01 by adi_ro »  
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HT-EXT
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Re: hz numbers on a 15" 2 driver
Reply #63 - 05/03/06 at 15:43:04
 
Bob do not get rid of the HWK. Just build another sub, of course on a budget, to complete the circus. WO36, WO32, or some of John suggestions that could be located in front of you to play lower bass than the HWK and use the HWK to fill in what you might be missing(50Hz to 100Hz). The klopping noise is the speaker being over driven to the point of bottom out just like the others said. With the amp only turn up a quarter of the way it seems that you gains on the receiver might be set to high. Not that I am the master of adjustment but when I play the movies you talked about with excessive gain on the receiver my HWK15 sounds like the "Budweiser Beer Wagon" pulling up to the front door and loudly I must say(klop/klop/klop). Just my "Brain Wiped" two cents.       HT-EXT
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #64 - 05/03/06 at 15:54:27
 
The "Budweiser Beer Wagon" pulling up to the front door is a good thing.  ;D

Bass setting on receiver is at 50%, less than that make the surrounds sound weak. (NO system eq unit)

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #65 - 05/03/06 at 16:05:55
 
Bob,
I wouldn't even worry about WinISD, since it won't model the center chamber.  Just go with Dan's dimensions for the big chamber and build it with an extension to your current bottom chamber.  To get it to his size just do the following (You'll need a sheet of plywood plus enough for say 3 or 4 shelf braces similar to your current driver cutout baffles, but only 1 thickness is needed, and a new end cap, same as your current one but the new interior dimension will be the same as your original cab exterior dimension):

Cover the 2 current bottom port holes from the inside.

Cut 4 side panels-  48"x (current exterior width + 1 material thickness).  I go a tad wider, then use a flush bit for the router to perfect the edge after assembly.

Cut 3 or 4 braces-  Original cab exterior width X depth.  Make a big cutout for air flow (driver cutout size should do the trick).

Now if you didn't do wrap around assembly the first time, you get to learn the easy way.  Attach the braces to one panel, flush with one edge.  Then, starting at the non-flush edge, attach the other panels one at a time to the existing panel and braces by wrapping them around the braces.

To make it so you can take it apart and get to the bottom driver but get a good seal, build a sealing ring on the interior of the new construction 4" from one end.  Say four 1" peices of material forming a ring around the interior, 4" from the end.  Using foam rubber as a gasket on that ring, it will give you a seal when you slide the end of the original cab into the new construction and attach it with screws.

Build your end cap the same way as the original.  I'd put the port in the end for simplicity and go with a temporary straight port at first and try a few different sizes for desired tuning, starting with Dan's recommended 4" by 17".  You'll probably settle on something a little shorter (higher tuning), since the other end is tuned a little higher than Dan recommended.  Once you get the tuning you want, buy flares for both ends.  I'd replace the coffee can port with a real flared port too, unless it has zero port noise.

That should give you impressive extension, eliminate the whacking noise, and make you feel like you're inside the fish tank when Darla taps on it in Finding Nemo.  If you still have some excursion problems at very low frequencies, then you'll need to tune coffee can port lower with a longer port.  Your current banging problem is most likely with your current bottom driver and chamber, not the top, so the new big chamber should resolve it.


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Bob
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Re: hz numbers on a 15" 2 driver
Reply #66 - 05/03/06 at 16:59:40
 
John, your cool, and Thank You. Helluva detailed description.
I buzzed through quickly once, will read it more methodically later today.

But a couple questions I noticed;
-We are talking a structure that's 7' 8" correct?
-Leave driver location alone
-I installed 1/2" fiber padding in top and bottom chamber. Should I; Leave it alone, / add more to extension, / or take it out stupid, it shouldn't be there in the first place (noticed no difference anyway).

Thanks again John,
Bob
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« Last Edit: 05/03/06 at 17:00:21 by Bob »  
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #67 - 05/03/06 at 19:22:51
 
Bob,

You got the idea, but I think more exactly 7' 10.25" with top and bottom caps and using the current bottom cap as a brace and cutting a big hole for air flow.  You have room to lay it on it's side right?

I wouldn't even take the drivers out or disconnect them.

Maybe save the padding for another project, or leave it there.

We haven't talked about your mains.  Do they go low enough to work with a sub that only goes up to 40-50hz ?
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« Last Edit: 05/03/06 at 21:39:43 by John in CR »  
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #68 - 05/04/06 at 18:57:43
 
Yes, I've got 11' in width behind the seating.

No John those mains won't do that.   Sad Angry  I'll have to tolorate the gap until I can find something to build.
Looking for plans for a center, and four surrounds.  ;D   I had a long conversation with Dave (hurdy) and Terry about driver numbers. I havn't got "the right stuff". Not even close. (I don't mind learning by my mistakes, just when those mistakes cost $, that's when it's harder to swallow.

....Got any plans in your back pocket?

Bob
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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #69 - 05/04/06 at 20:45:08
 
82 dB sensitivity on the RL-S sucks hard.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #70 - 05/04/06 at 20:47:05
 
Thanks 'J', you just made me feel soooo much better about my 89db........ Cheesy

Bob
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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #71 - 05/04/06 at 20:51:01
 
Well, considering your 89 dB will get as loud with 300 watts, you should feel proud. lol.

I mean, full wattage the RL-S thing will ony go to 122 db. (without the box in the equation....)
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« Last Edit: 05/04/06 at 20:51:54 by j_rock777 »  
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John in CR
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #72 - 05/04/06 at 21:10:02
 
Bob,

I would say let's change the plan to one of my backups, in case the HWKenstein didn't work for you.  You can even use the same construction outlined above giving you the flexibility to try both with the only waste being 2 end caps.  

That plan is to create 2 low tuned ported subs using the old HWK as one box with the driver on one end and the port on the other.  The new construction would be the other sub.  Put them both behind you firing at each other and the ports firing into the corners resulting in some extra down low.  That way you'll get the top end extension to meet your current mains and still get great extension at the bottom end.  You won't have quite the max output down low as the bandpass, but I'm pretty sure it will put a smile on your face, especially since you have 2 of those Dayton 15's.  It will be close to EBS (Extended Bass Shelf) tuning.

If you construct and connect your end cap/drive baffles in the same manner as the HWK end caps, then you will be able to try both ways.  The ported boxes will work better for music because you can stuff the ports for music and open them up for HT.
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« Last Edit: 05/04/06 at 21:12:05 by John in CR »  
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #73 - 05/04/06 at 22:44:50
 
Ok, John let me make sure I've got this correct.

-Build your idea as planned.

-Don't "SEAL" the double ports permenantly on the old HWK.

-You said; "Put them both behind you firing at each other and the ports firing into the corners resulting in some extra down low." --- You lost me there. "AT each other, but ports AWAY from each other?"

-Does the new box have the 3 ports just like Steves, or eliminate the doubles in the second build? The single center port would be 4" X about 17"?

I've modded this reply seven or eight times, got frustrated, removed it once, and started over.  >:(  Just when I think I've got it straight, and only have a couple questions .....  :o ? bla bla bla.


I THINK I'm with you John

Bob
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« Last Edit: 05/04/06 at 22:45:46 by Bob »  
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #74 - 05/04/06 at 22:49:21
 
One driver in each box mounted with magnet in lower chamber, so "top" chamber now includes the center chamber also?

Continue running amp bridged with a "Y" in cable?
Or, run each sub on it's own channel? It might have some kind of neat stereo thing, or it might just sound funky running it that way.

Bob
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« Last Edit: 05/04/06 at 22:58:25 by Bob »  
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John in CR
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #75 - 05/04/06 at 23:56:45
 
[quote author=Bob  link=1145573673/75#75 date=1146779361]One driver in each box mounted with magnet in lower chamber, so "top" chamber now includes the center chamber also?

Continue running amp bridged with a "Y" in cable?
Or, run each sub on it's own channel? It might have some kind of neat stereo thing, or it might just sound funky running it that way.

Bob [/quote]

No, each box would have the driver mounted on one end and a port on the other end, no more chambers.  You'd just be able to easily convert it to the HWKenstein later.

Another alternative is to build HWKenstein exactly as described and leave the cap off of the original cab.  Give me a few days to crunch some numbers first and get port lengths for your different options and do some modelling to be sure they all make sense.  Plus I have another idea that I need to model first, and it might involve even less construction.

The bottom line is that you don't need different drivers or amp and you can put what you already constructed to good use.  At most all you need is some wood and port(s) and end up with impressive bass.  

Sometimes I forget and talk about what I would build for myself.  I already have plenty of subs to choose from and most have much more output than sane people would want.  I'm into this mode now where I want to outdo Dirt Dawg's Big Whistles and make my chair move with big LFE's.
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John in CR
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #76 - 05/05/06 at 00:50:49
 
OK Bob,

Here's something easy to try this weekend.

Take the bottom and top caps off of your HWK.  

Take the bottom driver out and clamshell it with the top driver.  Wiring remains the same (opposite for each driver since they are still push/pull).

If you don't already have a 4" port, pick up a 13" piece of 4" PVC.

Block one of the bottom ports from the inside with a piece of wood.

Enlarge the other bottom port just so the PVC fits snugly from the outside (enlarge it to the top and center of the cab so you don't interfere with the bottom cap and try not to mess up your exterior finish work too much).  This is just a test for you at first, so let the port stick outside the box.  The tuning difference will be insignificant.

Try to smooth the interior and the exterior ends of the port as much as possible.  Don't worry too much because without flares on both ends, you'll probably get port noise due to turbulence no matter what you do even though that interior corner will act kind of like a flair.  Remember this is just a test, so ignore port noise.

Put the bottom cap on (leave the top cap off) and crank it up.

You now have a ported sub with a Vb (interior net volume) of right at 150L, with a port tuned to 19hz (actually a little lower due to port placement).  You should have a gradual slope from 50hz down to -3db at 19hz and a -10db at 14hz, which should be offset by room gain unless you have an open room configuration, so a net in room close to flat down into the teens.

The exposed basket of the driver on top will be hidden by the old top chamber.  That open chamber will have no effect on response at these subwoofer frequencies.  You will have traded some amp power for a smaller box and your max output is 6db less than possible with the same total power and 4 times the Vb.

Let me know if that does it for you and I'll help you finalize it when I get back from the beach Monday.  Gotta get back to burning CD's to bring with me to listen on Silver Iris OB-RLH's down at the beach.



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Bob
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Re: hz numbers on a 15" 2 driver
Reply #77 - 05/05/06 at 11:56:36
 
Thanks John... "Gotta get back to burning CD's to bring with me to listen on Silver Iris OB-RLH's down at the beach."

Don't work too hard.  :)

Goal #1 this weekend, build a deck. (WAF ya' know....)
#2 tweek sub. (my play time  :()

I'm sure I can find a reason to "need" to go to Home Depot to get one more nail for the deck. A couple pieces of MDF and a lenth of 4" PVC may happen to fall into my truck, 'How'd that happen?'  (just in case HWK needs steroids. Can ALLWAYS use MDF.)

Thanks again, John

Bob

p.s.  John said, "I already have plenty of subs to choose from and most have much more output than sane people would want.  I'm into this mode now where I want to outdo Dirt Dawg's Big Whistles and make my chair move with big LFE's."

This is a good thing!

Hey BTW John, how do you keep your projector bulb from exploding with the LFE's?
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« Last Edit: 05/05/06 at 12:02:55 by Bob »  
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #78 - 05/10/06 at 13:07:40
 
John, I bought "Master and Commander" based on Rap's recommendation a couple months ago. Very good movie. Was anxious to hear the LFE's.....My God man!   I had to keep turning down the amp, AND reciever to keep Mr. Klop at bay. I see the potential of the LFE, but frustrated that I can't "get there from here".

I think I've got myself another LFE referance movie....

One thing I'll say about the Daytons, they must've been made by Timex, 'cause they take a lickin' and keep on tickin'.

Bob
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gexter
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Re: hz numbers on a 15" 2 driver
Reply #79 - 05/11/06 at 01:07:39
 
Thats the movie we were seeing how much the big pair of SV subs could handle. we had to remove the wall lamps and stuff off the walls even before we turned the sunfire power subs loose.
felt like the carpet was rippling under our feet.
too bad it was my cousins system. Well maybe a good thing because my wife got pretty cranky during a couple cannon shots.
she was on the deck outside and I got a earful when we left.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #80 - 05/11/06 at 11:57:19
 
Hmmm Gex, I really hope it rains this weekend. Why you ask? Well you can't build a deck in the rain, BUT, you CAN tweek a sub!  
I'm looking forward to performing John's HWKenstien "adjustments" to the sub. I'm definetly missing something here in the LFE realm. In NO WAY am I rippling carpet much less 'wrecking the house'.

Bob
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gexter
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Re: hz numbers on a 15" 2 driver
Reply #81 - 05/11/06 at 13:08:36
 
LOL
Bob I am very interested in Johns mods as much as you, and rain is good news for both of us.
If you were closer I would  help ya so you could get to your sub. I like building decks Smiley No really!
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #82 - 05/11/06 at 13:22:37
 
I'm not that far away from you, well,... compared to John that is.  ::)

I like building decks too, just not when I'd rather be in my cave.  :'(

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #83 - 05/11/06 at 19:09:12
 
Try the simple one first.  It may be enough.  You can't beat that size, but port noise is my concern as an ultimate solution.  Plus, you can squeeze in doing the new bottom port while she goes to the store.  Then after dark (can't build pretty decks in the dark), you can swap the driver over to the top and be testing Master&Commander that night.  The HWKenstein won't work with your current mains anyway and the single isobarik BR may be enough for now.  That way you'll have a better idea of what you ultimately want (more extension, more max output, etc).  Plus you can start tracking down your room rattles and get wifey used to the concept of high impact LFE's.

Oh, I almost forgot.  Stop banging that back plate on your drivers.  You have some good drivers and you don't want to mess them up.
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« Last Edit: 05/11/06 at 19:15:00 by John in CR »  
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #84 - 05/11/06 at 19:57:50
 
Hi John, Port noise seems easily remedied by "creative flaring", I would think?

Forecast for St. Louis is RAIN 'TIL MONDAY,... WOO HOO.

As far as what I ultimately want,.... subsonic, no driver self destruction, good quality sound (doesn't have to be perfect. Remember it's not an audiophile listening room)

The mains John, are on "the cut list". They'll be going soon. I'd like to chat about those someday, as far as DIY options go. Just not in great detail at this point. --- Baby steps. Smiley

Wifey is getting "used to" overall volume capabilities of the overall system, but hasn't (obviously) had much in the way of LFE potential.  :-*

I get this panicy chill in my spine when I hear that noise. Scrambling for the correct remote in a pile of 6 in the dark to turn down the volume is getting old. (LFE is done and gone by the time the I.F. hits the eye anyway  >:()

I'm sure I'll be in the cave this weekend, a cuttin'. Shouldn't have a problem getting mods finished. I still can't post at home  ::) so I'll be getting back with results on Monday.

Hey, by the way, Just for grins / in the name of science.... Those Radio Shack SPL meters are pretty cheap arn't they ($35?)  Would it be worth the time/$ to get an A/B difference as far as max (unbottomed) output goes? What do you think?

Bob
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gexter
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #85 - 05/11/06 at 20:45:52
 
Get one. well worth the money.
I have to sneak a replacement into the house for my old one.
great for balancing HT I use it at first then by ears
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John in CR
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #86 - 05/11/06 at 20:48:07
 
Nothing like that is cheap down here.  Once I finally found an SPL meter, it was over $150.  While you are at Radio Shack, put up a programmable remote.  Once you get it going then you have just 1 that controls everything.  It's worth every penny and time spent setting it up.  Generally you just need on/off for the PJ, on/off + volume for the receiver, on/off + guide + chan(+/-) + prev chan for DirecTV and cable boxes.  I tried to put all functions of everything in mine, but ran out of memory, however, doing so gives you backup in case you lose a remote.  I still don't understand how some things on some units can't be done without a remote.  eg I can't even turn on my video enhancer unit, which centralizes all of my video sources, without a remote control.  That's just absurd, but I have backup now and remotes all go in one secure box if I need them.

Re port noise, big 2" radius flares help tremendously, but eg with the HWKenstein that's a lot of air to push through a longish 4" port and you may get a high enough velocity in the port that turbulence is inevitable.  With HT, a little port noise doesn't matter because there's plenty of other noise happening along with those LFE's that you don't hear it.  Plus you have your PJ noise to overcome already.  You'd have to be an organ music buff for it to be bothersome.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #87 - 05/11/06 at 22:51:39
 
PJ noise is VERY tolerable. Almost not even there!  :)

You may have missed an earlier question I had John, Do you do anything special to isolate the PJ from the LFE?
I'm already getting a slight amount of "jitter" on the screen from the HWK during 'Darla and the cannons'. (worried about bulb failure)

Why is the meter so expensive there, is it the cost of the equipment, or shipping? If it's the cost of the item, let me know if I can ship you something?

A buddy has a Sony 'Commander' he lent me. It won't control the Sanyo PJ for some reason. I got frustrated and put it down a month ago or so. I'll pick it back up one of these days.

Bob
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« Last Edit: 05/11/06 at 22:52:18 by Bob »  
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John in CR
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #88 - 05/12/06 at 00:04:19
 
Bob,

My homemade PJ mount is connected to one of support columns of a concrete wall, so only earthquakes can make it wiggle.  I don't think the LFE's will directly impact the bulb, but I agree that if what they are mounted to vibrates a lot it can't be good for the bulb at operating temperature.  Test it using a slow tone sweep with the PJ off first just to be sure you aren't stimulating a resonance in whatever supports the PJ.  You need to do that anyway to tie down room rattles.

Re the SPL meter, I needed it that week, plus my M/C doesn't work online, so the timing and cost didn't justify having someone buy it stateside and ship it to me.  Hard to find stuff can have silly prices, but our full time maid/nanny is only $200/mo and my skilled builder/helper is extremely happy with $20/day, so I don't complain, especially with shorts and tshirt weather year round and no A/C or heat needed.  Where I live it's lows of 60-70 at night and highs of maybe 80, year-round.  The sun can be brutal, but in the shade is always pleasant with a breeze.  I die down at sea level at the beach though.

I just use the top end Radio Shack remote, the one you can just point another remote at and copy the controls you want.  Quick and simple.
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« Last Edit: 05/12/06 at 00:06:42 by John in CR »  
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morpheous85
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Re: hz numbers on a 15" 2 driver
Reply #89 - 05/12/06 at 16:37:11
 
[quote author=Bob  link=1145573673/75#88 date=1147384299]PJ noise is VERY tolerable. Almost not even there!  :)
[/quote]

Ok, what is PJ noise?

Jason
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #90 - 05/12/06 at 16:43:16
 
Video morpheous,
Front screen projector (PJ). Cooling fan internal in the unit can be loud in some units. Projectors are usually located above and behind the seating position.

This is my rig. Notice the PJ tangling from the ceiling...

http://community.webshots.com/myphotos?action=showPhoto&albumID=549522535&photoI...

Bob
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John in CR
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #91 - 05/12/06 at 18:03:03
 
Bob,

Shorten that mounting pipe for the projector, which will reduce the wiggles tremendously, or do you have a beam between the PJ and screen like I do which requires a low mount?  If nothing is in the way then getting it up high will have other benefits;  less shooting in the eyes, less heads blocking the image when someone gets up, brighter image because more light reflects down to the viewing area, brighter image because less light reflecting to the ceiling, less chance of someone bumping into the PJ, and best of all, a better picture because you'd use less keystone correction, which distorts the image somewhat.
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #92 - 05/12/06 at 18:35:42
 
Yea, I've got "the beam" in the way.  >:(

Actually keystone is almost dead-on. It puts the lens VERY close to the vertical AND horizontal 1/2 way point of the screen.  ;D

Current location is as far BACK from the screen as I can get. Any closer to the screen, and the PJ will be directly over seating position. (don't want to smack it when I have one of those late-night over the head arm stretches, ya know.)

Here is a picture of the room with the "beam" (lower ceiling).... the "coffered" ceiling is drywall and is flanked by acustical tiles above and behind the seating position (shown in pic), and the same square footage of tiles is also in front of the screen. THAT area is several inches higher than the tiles you see in this pic. The reason was to get the screen higher off the ground. The reason for the lowered section of drywall, where the recessed lighting is, is the beams that hold up the house are inside the "coffer". (don't know how to spell that)

http://community.webshots.com/myphotos?action=showPhoto&albumID=549522535&photoI...

If you look in the far upper left corner of the picture, you can barely see the first ceiling tile. Notice it's higher than the tiles in the 'back' of the room.

Bob
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« Last Edit: 05/12/06 at 18:38:11 by Bob »  
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morpheous85
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Re: hz numbers on a 15" 2 driver
Reply #93 - 05/12/06 at 18:35:50
 
Ahh...it now makes sense. Thanks.

What about movie theater style where it's in a seperate room, shining through plexiglass or glass? Or, just build a plexiglass box around it (with ventilation of course).

Jason
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Bob
Ex Member



Re: hz numbers on a 15" 2 driver
Reply #94 - 05/12/06 at 19:16:48
 
morpheous, In another room would be a great idea, shining through glass. (logistics might be a bit of a challange, what to do in the other room to hide AND ventilate the rear of the PJ). Minimal video loss beaming through the glass, but probably acceptable.

Building a plexy box around it wouldn't be a good idea. The amount of holes drilled in it to get the needed airflow,... you'd end up hearing it anyway. Some guys have built "hush boxes" around the PJ. Simply a box with sound insulating lining, and an auxillary fan. But then the fan needs to be quieted also. Kind of an endless chain/dominoe effect if you ask me. PJ manufacturers are good about stating db output from fan noise, so you can be selective about the unit you buy. If it's going in another room, you have many more options on projectors to chose from since db's don't matter, see.

Now we're speaking my language. (feeling more confident talking about video than audio)  :D

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #95 - 05/12/06 at 19:43:53
 
Shooting through a piece of glass will eat 6% of the light output and Bob is already giving up a lot more than that with the see-thru screen (I see your speakers now on the screen only pic).

Bob,
You can probably pick up some stability by bracing those supports up above the ceiling tile and maybe a glass right triangle brace on each of the 2 front supports.  It all looks kind of wiggley.  Paint the supports all the same color at your walls for the PJ floating in the air look (at least the pair in the front).

BTW, work was done early last night, so we watched Finding Nemo with the kids.  We did the Darla scene a few times and just running  a single 100L ported 12" Shiva that is tuned to 24hz, we were getting quite a nice effect and that's probably -12db or more in the teens where the tapping really hits.  It was enough to get a little eyeball jiggling, but not the strange chest compression like in a car.  

I really think the iso loaded Dayton 15's in the box you already have and the single port making it a low tuned BR should hold you over until you're ready to get radical.  Plus the finish work is already done.  A tube for a port, bolts to clamshell the drivers, a small piece of wood to block the 2nd port, and something to seal is all you need.  Worry about HWKenstein later.
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« Last Edit: 05/12/06 at 19:45:47 by John in CR »  
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #96 - 05/12/06 at 21:09:43
 
John, The 3 speaker hole silouettes you see are no longer. Of the original 7.1 set-up, you obviously see the 2 front main surround. The system is now 5.1. The side surrounds are now the fronts. I had very little channel seperation with the fronts 9' apart, sitting about 17' feet back. Speakers behind cloth, well.... you guys don't need any more explanation there. Now the fronts are 12' apart, and 5' in front of the seating "plane". MAN, talk about stereo/surround seperation. 100% better.
The center is now sitting on top of a stand 1/2" below the bottom of the screen. Originally I wanted a 'clean' look, hiding 3 speakers would be idea,  but didn't stay that way for long.

I like the glass triangle idea John. Also may use extensive rubber for the feet of the PJ.

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #97 - 05/12/06 at 22:28:26
 
The center could go behind the screen.  Just turn the volume up for it to match.  You can also mount the PJ upside down, which can shorten the mount length by 4" and make it that much more stable.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #98 - 05/12/06 at 22:52:50
 
As far as the center behind the screen goes, if it's not 'right' then I'd rather not do it. Without spending a bunch on "acustically transparent" screen material, I've not found a way to get enough 'regular' material in the cut out to adequitly [sp] hide the fact there's a hole there without severely muffling the drivers. I've played with center channel volume but in the end it just sounds like a pillow over a speaker, just louder. For the throw distance and screen size I've got, I really need a screen material with about a 1.5 increase in gain.

Don't think flipping the PJ upside down will give anymore vertical hieght. The lens is placed directly in the center (top to bottom).

Well, gotta go, 6:00pm Friday night. Leaving work. Chat with ya' Monday.  ;)

Bob

p.s. weather may be clearing for the weekend.  :( Angry Sad Angry
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #99 - 05/12/06 at 23:35:32
 
[quote author=Bob  link=1145573673/90#99 date=1147470770]Don't think flipping the PJ upside down will give anymore vertical hieght. The lens is placed directly in the center (top to bottom). [/quote]

You did need the weekend.  You mount the PJ to the bottom of that platform and shorten the supports for same overall height of lense, but shorter supports will be more stable.

BTW,  It's good to get away from the speakers behind the screen.

With a new screen, if you can lower the top of it, then you can raise the projector.

I want to see smileys on Monday.  Do that conversion on your HWK this weekend.
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morpheous85
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Re: hz numbers on a 15" 2 driver
Reply #100 - 05/12/06 at 23:46:22
 
When I was talking about a box around the projector, I was thinking that to be practical heat wise (and to be an improvement sound wise), it'd basically need it's own ventilation duct. Might just be easier to do the separate room thing.

Jason
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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #101 - 05/13/06 at 00:41:19
 
With the lowered ceiling above your PJjust throw another fan in parralel with the fan on the projector.  The place that fan in the ceilign tile.  Build a box with a cut out for you lens, so just the tip sticks out.

Fan sucks heat from projector into lowered ceiling.  Movie goers are totally isolated from sound of fans.  And Pj is better braced against vibrations.

Heres a pick: (minus the walls, so you can see)



Notice the awesome fan I drew up?
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« Last Edit: 05/13/06 at 00:41:41 by j_rock777 »  
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #102 - 05/13/06 at 02:33:11
 
That's not enough ventilation.  The only way I'd box up a projector is if I was sure the projector was getting more fresh air flow than the projector got naturally.  You would need some kind of ductwork going to the intake.  Most projectors have multiple fans front and back, plus another one to force air through the bulb housing.
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gexter
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Re: hz numbers on a 15" 2 driver
Reply #103 - 05/13/06 at 06:25:35
 
Anything I have to keep cool I keep it cooler.
I tend to replace anything with a fast moving loud fan with a larger slow moving one. preferably with twice the CFM.
Nasty habit left over from Being a PC modder and overclocker.
I also undervolt the oversized fan and then add or subtract resistors to find the temp I am comfortable with.
this applies to 12 v fans. you also have to watch for keeping the voltage higher than start up voltage.
if it don't spin at 7V you need another fan to use with a lower startup voltage, as an example.

I know you can build a circuit to solve this but I am too lazy.

Blowing air in and in bigger quanitities leads to more dust unless your filtering and then you have filters to check.
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« Last Edit: 05/14/06 at 14:33:20 by gexter »  
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #104 - 05/15/06 at 11:56:16
 
[quote author=John in CR  link=1145573673/90#100 date=1147473332]
I want to see smileys on Monday. [/quote]


Ok John, here's the smiley after the mods......  :(   Cry

I've got numbers, I'll be 'organizing' them today. Will post when they're in a 'readable form'

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #105 - 05/15/06 at 12:32:29
 
Bob,

Before the numbers, please tell me exactly what you did in the way of mods first.  After reading that you painted a deck, I'm not sure what to expect.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #106 - 05/15/06 at 13:33:42
 
LOL John,

I didn't use 'regular' paint, it was supposed to be 'FOR' exterior use.  ::)

http://www.behr.com/behrx/act/view/products_detail?prodGroupId=53&catName=Wood+W...

OK, here we go...

- Removed both caps
- Removed both drivers
- Sealed one of the lower holes
- Installed 13" X 4" PVC port tube in other lower hole (slightly enlarging the original hole
- installed lower cap
- clamshelled both drivers in upper chamber (left the cap off)
- wired out of phase

Look ok? ) I think there may have been a Budwieser or two in there as well.  ;)

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #107 - 05/15/06 at 14:12:48
 
Sorry Bob, just couldn't resist.  I already knew decks were stain only (if anything other than just sealer).  Before I may have tried paint too.

It sounds like you did everything right.  What did the sub sound like?  My guess before hearing your result is that you wired in series instead of parallel (sorry I didn't mention that before) or maybe a receiver setting, amp problem, loose wire etc.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #108 - 05/15/06 at 14:35:10
 
[quote author=John in CR  link=1145573673/105#108 date=1147698768]Sorry Bob, just couldn't resist.    [/quote]

No harm done, I can take it.  :D Undecided Kiss

Wiring comes from amp to the ,... oh, what's it called, the "terminal block" on the sub. Inside the sub, the individual driver wires go directly to the spades on the back of the block, like a "Y" connection. ALL connections are soldiered, soldered? Dammit man, can't spell on a good day, much less a Monday morning.

Is that wired ok?

As far as sound quality goes, I "THINK" it was better, but I was more intent on looking at the meter than listening to quality (although I was listening for Mr. Klop to come to the door  :-X ). It was getting late and testing max SPL on Mothers day evening at dinner time was starting to strain the WAF. Main goal was to get numbers.

Went to Radio Shack to get the meter, the man said they don't have the analog meter anymore. "BUT, here's this cool nifty looking digital meter that's sooooo much cooler".  ::)
Never liked looking at a digital meter for things that "move" across a spectrum rapidly. That's what analog is for. The damn thing was $57 with tax, including the $3 9volt battery they ganked me for.
Shouldn't have bought it, I SHOULD have held out for a "real" meter, but when I have my heart set on something, It's mine. (Just like my 7 year old...Gotta have it now or the world will stop turning.)
Thinking about taking it back?

Here it is.....

http://www.radioshack.com/product/index.jsp?productId=2103667&cp=&origkw=sound+l...


Bob
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« Last Edit: 05/15/06 at 14:36:42 by Bob »  
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #109 - 05/15/06 at 15:33:13
 
Wiring-  Series, parallel or separate?  Series means through one driver to the other then back to the amp.

Did Mr. Klop show up?

What were you playing during your test?  Test tones?

I have an SPL meter.  How many times have I used it?...Less than I have fingers.  How many times have I used it for a sub?...None

Did you put Nemo on and see if it felt like you were in the fish tank when Darla was tapping?  That's a really good test.  Do you have Harry Potter 2?  The willow whomping the car is also good because it has a good variation of frequency as it groans with a nice impact to really feel when it slams to the ground.  Also, the train scene about a minute earlier.  You should feel the near miss of a raging locomotive.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #110 - 05/15/06 at 16:11:00
 
Ok, did (4) tests. First 3 were done never touching amp setting I have it set so the Daytons "just barely" klop. Last test turning amp output from 40% of max to 50% of max. 1st with unmodded HWK, 2nd after mod, 3rd after reinstalling top cap (just for grins) and 4th with more amp power. Chapter 3 in Star Wars III has two fairly long LFE rumbles, and Master & Commander, Chapter 4 has a nice cannon volley.

In parensesis is an (sk), that means I heard a "Slight Knock" from the drivers. No (sk) obviously means no knock heard. the "xxxx" on Master and Commander means the WAF had reached "IT'S max excursion"   Lips Sealed
Measurement taken at ear height, in the center of the 4 HT seats. ( also did a 3' foot distance measurement from the 4" port. The numbers mirrored the seated position measurement, just a few db's higher of course. )

STAR WARS III (chapter 3, 1st and 2nd extended LFE rumbles)


           Decware HKW       after mod      top cap    50% amp
1st rumble   105db(sk)        104db(sk)     105db      107db(sk)
2nd rumble   108db(sk)        107db(sk)    108db      109db(sk)

Master and Commander Chapter 4 Cannon volley
                104(sk)            103db          105db      xxxx

By the way, my 6 horsepower Campbell Hausfeld air compressor produces 88 db from 3 feet.  ;)
Will post numbers at a later date on what my 2 year old daughter can produce db speaking. Would like to know the hz rating. She can reach some unbelievable highs hz AND db's.  :D

Bob
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #111 - 05/15/06 at 16:56:37
 
[quote author=John in CR  link=1145573673/105#110 date=1147703593] Series means through one driver to the other then back to the amp. [/quote]

...."back to" the amp?  The "back" is thowing me off..?
Positive and negative to the sub, then "Y" to each individual driver, like a fork in the road.

Nemo on DVD was borrowed, the kids only have it on VHS. I won't even install a VHS in the room, imagine what 480X480 looks like blown up that big....  :-X

haven't tried tones with the meter. The Potter movie you mentioned is on my 'needed' list.  :)

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #112 - 05/15/06 at 17:40:09
 
Bob,

First, shame on you for testing your sub on Mothers' Day.  You burned up any credits you had and need to do something extra special to get some back.

Second, your tests don't really mean much at all except that they play up to 105db+ at the seating position and that you're playing low enough frequency info to send both the HWK and ported alignments into over excursion.  What it doesn't tell you is how low in frequency you were getting what output.  

Those LFE's have a wide range of frequencies in them.  The cannon shots, for example, probably have a burst across the entire range below the XO point set on your receiver all the way down to about 10hz.  It doesn't surprize me at all that the output was close to equal.  What it doesn't show is a comparison at say 20hz or lower.  Could you hear/feel a significant difference or were you too busy with your new gadget?  Was it enough feel or do you need more, because 105db is pretty darn loud?

If you like the tuning with the top on, that will give you the ability to go louder, because the top chamber is helping to control excursion better than the free air of the open top.

Put the ported end in the corner.  That will give you some boost on the bottom.

Lower tuning (longer port) will enable you to apply more power (go louder and lower) before going into overexcursion on the lowest material.

You should walk around the room while playing the Star Wars rumble to make sure you don't have a placement issue putting your seating area in a relative null.

If after trying all of that you are positive that you want more output, then you need 2 larger boxes, ported and tuned to the frequency you want  OR make your room so it can be closed, which will probably net you about 10db of room gain down at the bottom end of the range.  Your open floor plan prevents much at all in the way of room gain.  Two boxes will net you +6db at the same total power.  Half of your power is currently going to waste for no gain (except smaller cab size) with the isobarik alignment.  You double the alignment (+3db) and double the useful power (+3db).  If you are sure you need more, I'd try HWK size first with only one driver, in place of the top cap, and tuned even lower with say a 17" port.

Something to keep in mind is that with this very low tuning you are getting a shelved response, Extended Bass Shelf (EBS).  Below about 50hz the output drops by 5-6db and stays fairly level down to port tuning.  Typically this is a good match when room gain is factored in netting a pretty flat response.  A max flat response would require tuning to 25hz or so, and you'd give up bottom end extension.  I just question how much room gain you are getting.

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Bob
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Re: hz numbers on a 15" 2 driver
Reply #113 - 05/15/06 at 18:35:49
 
[quote author=John in CR  link=1145573673/105#113 date=1147711209]Bob,

First, shame on you for testing your sub on Mothers' Day.  You burned up any credits you had and need to do something extra special to get some back.
[/quote]

Fortunately we have a very stong marriage ( ie...she tolorates my toys)

[/quote]
Second, your tests don't really mean much at all except that they play up to 105db+ at the seating position and that you're playing low enough frequency info to send both the HWK and ported alignments into over excursion.  What it doesn't tell you is how low in frequency you were getting what output.  
[/quote]

Is there something a fellow could get to measure hz and db simultaneously, or would that be yet another toy in the hands of someone not needing more toys?

[/quote]
Those LFE's have a wide range of frequencies in them.  The cannon shots, for example, probably have a burst across the entire range below the XO point set on your receiver all the way down to about 10hz.  It doesn't surprize me at all that the output was close to equal.  What it doesn't show is a comparison at say 20hz or lower.  Could you hear/feel a significant difference or were you too busy with your new gadget?  Was it enough feel or do you need more, because 105db is pretty darn loud?
[/quote]

I believe it was you that said something about the level of sanity regarding your subs.  :) Am I correct  ;D  Yes, I was mainly concerned with the toy last night, but it seemed to be better. Over the next few days, I'll have some real play time to actually HEAR it.

[/quote]
If you like the tuning with the top on, that will give you the ability to go louder, because the top chamber is helping to control excursion better than the free air of the open top.
[/quote]

Would making the top port a smaller diameter create more air restriction, giving the ability to go louder?

[/quote]
Lower tuning (longer port) will enable you to apply more power (go louder and lower) before going into overexcursion on the lowest material.
[/quote]

Install a 90 degree fitting on the PVC to add additional pipe?

[/quote]
If after trying all of that you are positive that you want more output,
[/quote]

Absolutely

[/quote]
OR make your room so it can be closed,
[/quote]

Very hard to do with the archway. Light switch just out of view on right side of arch. And there would be three doorways in very close proximity of each other, all swinging towards each other.

[/quote]
If you are sure you need more, I'd try HWK size first with only one driver, in place of the top cap, and tuned even lower with say a 17" port.
[/quote]

I'd like to go down this path.


...Gee, I hope all this quoting works.

Bob
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #114 - 05/15/06 at 18:37:36
 
Well, that looks like hell. But I suppose a fairly smart guy could figure what it was I was attempting to do.   Roll Eyes

Bob
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« Last Edit: 05/15/06 at 18:38:17 by Bob »  
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #115 - 05/15/06 at 19:46:22
 
Google  "ttg test tone generator free" and download Timo Esser's tone generator that is free for a month.  If your puter isn't connected to your system, just make some tone files and sweeps and burn them on a disk.  Then you play a frequency from the generator and measure it with the SPL meter.

Be absolutely sure your other speakers are set to small or are off for running that kind of test or you'll blow them for sure.

Keep the port outside the box, so you can easily try different lengths first.  Don't put it inside until you get to the tuning you want.

You might be able to get away with a matched pair at the front of the room in the corners with the right color scheme.  I think that will load your room better, but that's probably just a few dbs at most.

Before building something new, check the SQ and max limits with the top cap on.  Also with the top off and lower tuning.

Yes I think a smaller diameter port and/or longer port will help control excursion to a lower frequency, but too low tuning could cancel some output from the big chambered end because they are at a different phase.

Just for grins, next time you have a sheet of ply or mdf, before you cut on it, place it over the opening leading out of the room and have someone hold it in place while you play some loud LFE's to see how much more room gain is possible.  That way you know whether or not it's worth trying to figure out if it's worth any trouble trying to make that work.

I'd say measure and listen to what you have first.  Going for extreme output is kinda fun, but realistically it will never be used, because your volume would be up way too loud for the rest of the audio spectrum.  Plus, if you do use it, you'd have to start worrying about cracks in sheetrock joints and other damage to your house.  Also, Dad's setting the example now, you may not enjoy the 7yro's taste in music in a few years and he/she will want to blast their's too.

Keep in mind that HWK size is about 100L too small for true EBS tuning.  It looks like Bassboy and I are going to try some new that we've been discussing over in the HT section.  If my 10hz version works, using a 15" driver, then that might be your answer once you want to cut some wood.  Tom Danely, a renown sub designer, is getting 120+db at 20hz with a pretty compact model with a 12" driver.  Mine will be 8ft x 1.5ft x 3 or 4ft and it looks like you have room for that behind your seating area.  http://news.ecoustics.com/bbs/messages/10381/169045.html
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #116 - 05/15/06 at 22:15:24
 
John, that's a lot of very good advise you just gave. Endless tweeking..... Several weekends worth I'm sure.

I like the specs on the HVAC cold air return you gave ( well, that's what it looks like  :) ). Very impressive. But for 3 grand + shipping + suitable amp, I can play in my toy room for a looong time spending the $$$ elseware.

I have been lurking the thread with yourself and bassboy with great interest. Yes I'm luck in that respect, PLENTY or room behind the seating. (unplanned, over-exagerated projector throw distance/screen size specs given by the manufacturer provided me with lots of extra room. Putting the seating where it was originally planned would put the PJ at adams apple level imediately after standing up from the seats.  >:()

I have thought about a temporary "door" but if memory serves, the opening is 5'wide 7'tall. Would have to make something. Really regret not having a door there. Didn't think I needed one 3 years ago when I built it.

Thanks again John. I'll be hanging in the HT thread to see what my next POSSIBLE project would be if the HWK doesn't work out.

Bob
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #117 - 05/18/06 at 22:39:17
 
[quote author=John in CR  link=1145573673/105#116 date=1147718782]
Keep the port outside the box, so you can easily try different lengths first.  Don't put it inside until you get to the tuning you want. [/quote]

So, let me get this right.  The total port lenth isn't the issue, it's how much of it is inside the enclosure? Does it affect tuning at ALL, or just not enough to worry about for tuning purposes only?

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #118 - 05/18/06 at 22:56:44
 
[quote author=Bob  link=1145573673/105#118 date=1147988357]

So, let me get this right.  The total port lenth isn't the issue, it's how much of it is inside the enclosure? Does it affect tuning at ALL, or just not enough to worry about for tuning purposes only?

Bob [/quote]

Bob,
The port length and diameter is the only issue with a cab that large.  When it's inside the box, the volume taken up by the port (and the volume taken up by the driver) is subtracted from the total volume to get to the Vb (the volume of air being tuned).  In your case the volume taken up by the port is immaterial in comparison, so you can determine the tuning you want by fiddling with your port length with it outside of the cab.  When you get to where you want, then worry about how to fit it inside the cab.  ie  Don't worry about 90 degree bends and stuff now.  Also, you can try different tuning in seconds, instead of having to take the bottom cap off and make changes.
John
the world's foremost believer in the KISS principle.
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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #119 - 05/19/06 at 00:50:59
 
I have been whatching this thread for some time.  I believe for home theatre you need to stop and step back.

Now realize the HWK is not going to work.

Now start over from scratch.  Working around the space, drivers and amps you have, design a new enclosure.  For hometheatre and double duty as music, the only option IMO is a low tuned ported enclosure (PR if needed).  

No offense, these ideas are great, but I think you have a much better idea of what you want, and can easily get it without haveing to modify a box.

And guessing at volumes and ports is fun for a few hours, but after awhile grows tiring, I suggest a program to model something.  Even if it is just to get a starting point...

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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #120 - 05/19/06 at 01:42:20
 
J_Rock,

You haven't been reading very closely.  Bob's HWK has been converted to a low tuned BR using only minor changes and NOT having to build a whole new box.  I did some quick and dirty modelling for him and using the center and bottom chambers as his Vb, he could tune pretty low using isobarik loading.  Now he's going to measure what he has, to figure out where he wants to go.

If his mains reached down to 40hz, then the HWKenstein would be the most compact way to get prodigous output down in the low teens.  The alternative is 2 big (350L+) BR boxes, if the isobarik BR doesn't have enough output.  About the only thing that hasn't been discussed is a rumble filter to protect his drivers from over-excursion.  Before getting into that, I was just going to let him run some tests with a longer port.
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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #121 - 05/19/06 at 02:45:11
 
I understand that much, I am suggesting that he DOES start over.  

Of course after testing the HWKenstien.

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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #122 - 05/19/06 at 03:13:38
 
[quote author=J_Rock  link=1145573673/120#122 date=1148003111]I understand that much, I am suggesting that he DOES start over.  

Of course after testing the HWKenstien.
[/quote]

He can't really use HWKenstein, even though I'd like to hear about it too.  The thing is, he already has a finished 200+L solid cab.  Using the 150+L of the bottom 2 chambers of his HWK may work until he builds new mains.  The 6th order BP with the HWK top cap on may even work well enough as a stop gap.  Another option to try is to iso mount the drivers in place of the top cap.  That will allow more optimum mid teens tuning of the ready made BR alignment.  Starting from scratch cabwise is the last thing I'd do.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #123 - 05/19/06 at 12:21:30
 
LOVING the discussion guys, keep going..  ;D

Weekends are best for letting the HWK "stretch it's legs" so to speek. So I havn't done much listening at high db's during this past week. I do believe it sounds better John. However, I am looking to go lower in the hz, and higher in the db's.  

Tell me if this correct..."Adjusting the port lenth will only change hz range, and not affect db's or prevent driver bottoming out".

If this is true then I would be interested in exploring other modifications. ie, trying iso loading drivers mounted ON the top cap, increasing Vb, or...?... letting more sawdust fly?

Tell me what this would do,...
- Lay original HWK on it's side, facing dual port holes up
- Build carbon copy HWK enclosure facing dual port holes down
- Lay it on it's side, on top of other HWK (the, now "quad holes", mating with each other
- iso mount drivers in the top cap of, say... bottom HWK
- install the adjustable port(s) in 'what would have been' the top cap of upper HWK (now the end of the upper HWK)

Anybody for some ascii?.....
                                                         
                                                         
     -----------------------------------
     I                                               I
     I                                          -----    /__ ADJ. PORT
     I                                          -----    \
     I                                               I
     --    ------------------------------I
     I                                            __/
     I                                           [        /___ ISO DRIVERS
     I                                           [__     \
     I                                               \
     -----------------------------------I

Bob
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #124 - 05/19/06 at 13:56:11
 
no way im going to read all this thread, but if the origional hwk is a good desighn (and im assumeing because steve d desighned it, it is) why all the modding? if built to plans with the right drivers it will deliver lots of accurate bass.mine does anyway ??? in a nutshell, whats wrong with the origional hwk for your application bob?
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #125 - 05/19/06 at 14:00:26
 
turning the knob up just creates the horrible 'klopping' sound from drivers hitting mechanical limit.



ah, the above quote is from bobs first post and seems to be where it all started.seems to me like you need heavier duty drivers. 900 wrms @ 25hz is gonna punish most mediocre drivers.
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #126 - 05/19/06 at 14:02:07
 
[quote author=Adrian D.  link=1145573673/0#2 date=1145626960]series II have only 8mm xmax and can handle 'only' 300w. so my guess is that, with 450w to each of them they're bottoming out.

[/quote]

post number 5?
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #127 - 05/19/06 at 14:04:17
 
[quote author=Bob  link=1145573673/0#3 date=1145628689]Sorry Adrian, I assumed the world centered around me, and that everyone had read the entire thread "amp to make Daytons happy".  ::)  :'(



The Daytons I've got are the series II. They've got an xmas of 15.1, and rms watts of 350, 600 max.

[/quote]

450 still pushes them beyond theyre ability.especially when you really want all that output below 50hz!
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #128 - 05/19/06 at 14:17:01
 
Even when the amp gain is at 40%?  :'(

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #129 - 05/19/06 at 14:18:50
 
Hi Bob,

Lower tuning by lengthening the port will give you excursion control down to a lower frequency, so playing the same content as your last test, you should be able to turn it louder before running into excursion problems.

The tuning frequency of your box is determined only by the net volume of enclosed and the diameter and length of your port.  Increasing the volume, lengthening the port, or decreasing port diameter lowers tuning.  Content below the tuning frequency quickly causes excursion problems, because the alignment can handle very little power below tuning.  Typically a "rumble filter" a high pass filter is used to protect your driver from content below tuning.

The T/S parameters of your driver determine what size box is needed for optimum performance tuned to a specific frequency.  Isobarik loading cuts the Vas in half and the driver only needs to see half the box size for the same performance at a given port tuning.  With iso loading you don't need any more box than you already have.  In fact, the way you have the drivers mounted now gives you an effective volume equal to almost 340L for a single driver and moving the drivers up to the top cap wouldn't help.

At this point I'd suggest trying 2 things:  

First, see if you can live with the SQ and tuning of your current box with the top cap back on.  That alignment will give you more excursion control down low, but it will also limit integration with your mains.  As you saw last weekend, it will allow higher output with the content you were playing in your test.

If that setup won't work for you, then try tuning the existing setup to a lower frequency with some longer ports.

You can use the LFE's you used before for your testing to give you an idea of performance, however, you don't know low that content goes.  I'd mix some more LFE's in for that kind of testing.  Let's say you're tuned to 15hz and the LFE's have 10hz content, you won't be able to turn it very loud and see how your sub performs from 15hz and up.  If you tune to 10hz, then you'll give up a lot of max performance compared to 15hz tuning.  That's where the tone generator comes into play, because it will enable to properly test performance and extension.  Then once you determine the desired tuning frequency, you know what rumble filter you need to protect your drivers which will enable you to crank it as loud as you want without the banging noise no matter what LFE's you send to it.

The bottom line is that you really don't need to let any sawdust fly, because HWKenstein won't integrate with your system.  After trying the stuff above, and you're still feeling adventuresome, then you could try just a single driver (not iso) mounted in place of the top cap using your current port.  That will give you a slightly underdamped alignment close to an EBS alignment.  It won't give you any more output or driver protection below tuning, although it would lower tuning by a couple of Hz compared to what you have now.  It will just tell you what to expect with 2 of the same boxes.  Just test it and add 6db.

You already have butt shakers, so realistically you don't need super low tuning for your sub, you just need a rumble filter.
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #130 - 05/19/06 at 14:27:02
 
i saw some pictures recently of i think your ht room? if that really is how serious you are about your ht then getting something like these



http://www.ddaudio.com/dd/caraudio/woofers.asp?series=3500d


is definately not out of the question.imo Wink
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #131 - 05/19/06 at 16:47:18
 
Even more good advise John, That'll keep me busy for awhile.  ;D

Hey 60, a 10.6 lb magnet, OMG! 3 inches Xmas, OMG!!! that's cool, but they arn't very forthcoming with prices are they?
Yes, to answer your question, I am serious about the room. Usually as serious as my budget allows  ::)
2X4's and drywall are cheap, so you can do cool things with design that increase the cool factor and help acustically (hopefully)
As far as the butt shakers go, they stopped working last night!?  ??? Cry
I've heard may referances to rumble filters, mostly seeing plate amps with the filter built in, but I'll do some research on an 'add-on' filter. Sounds like an interesting idea.

....and now for a completely different idea.
You may have see the pic of the rear wall. The drywall is about 9" from the concrete foundation wall, due to the upstairs 4" sewer pipe running across the wall. I didn't want "the ugly box" that a lot of basements have that incase HVAC and plumbing. Soooo, I brought the wall out. The point to all this is, ... IB. Is it feasible? Is it feasible with my drivers?

I've seen the radical set-ups on the infenitly baffled site. Neat ideas

Bob
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Adrian D.
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Re: hz numbers on a 15" 2 driver
Reply #132 - 05/19/06 at 17:28:56
 
60, i'd say 2 rl-p 15s.
amp gain@40% doesn't mean the subs are seeing 40% of the power.
one funny thing i noticed on my sub-amp: the x-over has power indicators (these are based upon input sensitivity) and the lower the bass goes the more power the sub is getting. gains untouched. it could be the weird headphone out i use as a pre-amp.
but the thing is that the lower you go down in hz, the more the subs have to move to produce the same spl. 8 mm xmax is pretty limiting.
i agree with john, because lowering the tuning will help. but only untill you will play something below tuning...
sealed could be the best option.  
the subs have to have high-ish qts to use in IB.
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« Last Edit: 05/19/06 at 17:40:05 by adi_ro »  
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #133 - 05/19/06 at 18:02:19
 
[quote author=Adrian D.  link=1145573673/120#133 date=1148056136]the lower the bass goes the more power the sub is getting. gains untouched. [/quote]

Well Adrian, That seems pretty obvious now that I see it in writing. I'm fairly dissapointed, and embarassed in myself for not realizing that. Several hundred watts at 100hz is much easier than at 25hz. Thanks for the reality check. That's why you received that A- !

Bob
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #134 - 05/19/06 at 19:03:00
 
[quote author=Bob  link=1145573673/120#132 date=1148053638]

Hey 60, a 10.6 lb magnet, OMG! 3 inches Xmas, OMG!!! that's cool, but they arn't very forthcoming with prices are they?



Bob [/quote]

but you dont get high end per..... really high end perfromance from an entry level sub.$120,000 cars are just that much better than $12,000 cars. sure crazy subs are expensive, but they will give you what you looking for.all the time you invest with 2x4s and drywall etc, thats all worth money isnt it? i say build a hwk the way steve designed it, and throw a pair of serious subs in there, then you get to sit back and enjoy.on the other hand my e bay $40 pair of old skool 15" jbls can fill my garden with enough bass to make me feel quite ill after a few hours Roll Eyes i have used ib installs before and as far as im concerend, the hwk gets as low as any ib stall ive ever used.
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Adrian D.
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Re: hz numbers on a 15" 2 driver
Reply #135 - 05/19/06 at 19:18:06
 
[quote author=Bob  link=1145573673/120#134 date=1148058139]

Well Adrian, That seems pretty obvious now that I see it in writing. I'm fairly dissapointed, and embarassed in myself for not realizing that. Several hundred watts at 100hz is much easier than at 25hz. Thanks for the reality check. That's why you received that A- !

Bob [/quote]
rotfl, i've topped my previous scores on all exams this year. i couldn't believe it.
hmm, i never applied anything i learnt in school, except maths
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #136 - 05/19/06 at 19:48:39
 
Bob,

Don't buy into the hype.  Your 2 drivers will almost equal the performance of one of those 15s that cost so much that they are afraid to post the price.  If you had a 3rd driver, you could out perform it.  

If your amp doesn't have a LF protection filter (rumble filter), then it's really not something to worry about now because you have to know what your final setup is first.  ie at what frequency you need it and whether you need one or two and how your drivers will be wired.  You have to know the ohms and hertz, for the correct filter.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #137 - 05/19/06 at 19:54:18
 
60, Good bass from a couple of used 15"ers outside is different from <20hz in a movie soundtrack though, don't ya think?  I'll never say the HWK doesn't crank. Ever. It'll knock your socks off with a good source for music, no doubt about it. Steve has a helluva design there.

It just won't go low enough, loud enough on movie soundtracks for psycho's like me.

The IB thing was a passing thought/daydream. Not something I had my heart set on.

I do know the difference between a Ferrari and a Yugo, but I've seen too many 'hotrodders' that can build a rod that would keep the Ferrari looking nervously in the mirrors for a fraction the price. (That's where I want to be, I'm just having a hard time getting there.)  :)

Bob
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #138 - 05/19/06 at 19:56:47
 
[quote author=John in CR  link=1145573673/135#137 date=1148064519]Bob,

Don't buy into the hype.  Your 2 drivers will almost equal the performance of one of those 15s that cost so much that they are afraid to post the price.  If you had a 3rd driver, you could out perform it.  

If your amp doesn't have a LF protection filter (rumble filter), then it's really not something to worry about now because you have to know what your final setup is first.  ie at what frequency you need it and whether you need one or two and how your drivers will be wired.  You have to know the ohms and hertz, for the correct filter. [/quote]

Understood John.  ;)

Bob

P.s. No, it does'nt have a filter.
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« Last Edit: 05/19/06 at 19:57:48 by Bob »  
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #139 - 05/19/06 at 20:24:02
 
bob...and john,
forgive me for flogging a dead horse but, if bobs drivers are bottoming out, doesnt that mean they have reached the end of their capability, and to get 'more' you either need more drivers or a 'better' driver? bob have you tried just a straight sealed box? apparently the roll of down low is 'best' in a sealed enclosure, also the subs might be able to handle more power? just a thought. personally i would have thought a pair of daytons and 900 watts would be more than adequate for watching a movie? cant imagine what your trying to achieve Roll Eyes tyranosaurus rex @ realistic levels would require a 30 ton creature jumping up and down outside your door.i wont comment further, john is way more qualified to asist you than i am. but i do believe some of the 'hype' those beastly subs sure do pack some punch. Grin
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #140 - 05/19/06 at 20:45:51
 
[quote author=Bob  link=1145573673/135#138 date=1148064858]60, Good bass from a couple of used 15"ers outside is different from <20hz in a movie soundtrack though, don't ya think?   [/quote]

i have tested my hwk with a test disk and had useable output
below 20hz with my e bay jbls
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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #141 - 05/19/06 at 21:25:15
 
Bob's drivers are fine.  The HWK is not a LFE sub.

The HWK design ports at higher frequencies for the CLUB bass its meant to be used for.  Below these frequencies the enclosure does little to curve the driver's movements.  Hence the bottoming out.

Those DD audio subs will nto work for HT, a FS of 32Hz makes them unusable for sub-bass frequencies.

The Rlp subs might work, but again I do not believe in their SQ.

So John is absolutely right in sticking with your series 2 woofers.  They have a low Fs and a decent power handling.  Not that Power is that much these days.  Linear throw is what will determine the viability of any woofer for sub bass frequencies, 2 15s with 12 mm xmax or 24 mm of travel will move plenty of air.

With that said, John is again right in his thinking.  I just differ slightly in that I believe you need to get out of the moding HWK scene and start over.  There are many different options to explore:

~Low Tuned Horns - Although Huge they are my favorite type of Bass
~Transmission Lines - The main objective of these enclosures are as "Bass Enhancing devices."
~Low Tuned Large Boxes (Notice "boxeS"  Stereo subs for better room node excitiation.)


I think Bob really needs to step away from the ISO config though.  HT is all about air movement, ISO halves his capability when compared to 2 seperate 15s.  The only gain being a smaller enclosure and decrease in even order distortion due to suspension non linearities (Which I suspect these daytons have few to begin with).

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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #142 - 05/19/06 at 21:35:12
 
[quote author=J_Rock  link=1145573673/135#142 date=1148070315]Bob's drivers are fine.  The HWK is not a LFE sub.

The HWK design ports at higher frequencies for the CLUB bass its meant to be used for.  Below these frequencies the enclosure does little to curve the driver's movements.  Hence the bottoming out.

[/quote]

so what freqencies are we talking about? if my car sub plays flat-ish from 80 down to 20, LFE frequencies are how far below that? 19, 18, 12,?? and how much imformation is on the movie recording that low?

is there a significant difference between music lows and movie lows? does bob need 2 seperate subs, 1 specifically for movies and another for music?
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #143 - 05/19/06 at 21:38:58
 
Responses range from narrow bandwidth to wide bandwidth with typical responses down to 13 HZ on all three models. Box can be built for 8's,10's, 12's, 15's or 18 inch woofers.  Note: The design is for a 15, however the the box can be scaled down (and so the performance) to smaller drivers but you will have to specifically tune anything below the original 15" design.
Using musical instrument woofers (ex. PEAVEY BLACK WIDOW) you get tight full accurate bass from 200 down to 40 HZ. Using subwoofers you get big warm full bass that can on command create Subsonic pressures lower than 20 cycles.  


thats a quote from decwares hwk page. i believe the hwk IS able to produce very serious low bass.how much lower than 13 hz do we want to go?
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« Last Edit: 05/19/06 at 21:39:32 by 60ndown »  
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #144 - 05/19/06 at 21:50:19
 
Check reply #22 and #28 on page 2.

Bob
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« Last Edit: 05/19/06 at 22:12:01 by Bob »  
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #145 - 05/19/06 at 22:02:46
 
60, If I understand correctly, drivers (cone travel distance) can be controlled by how much air is allowed in and out of the enclosure.

Playing with airflow restriction is a form of "brakes"/"shocks" for the drivers, changing the max cone travel.

So if this is true, to continue the automotive analogy, it would be like antilock brakes, or traction control. The system allows life to happen "as it will", until it see's something it doesn't like, then it interveens [sp] and reigns it back in just before bad things happen (tires lock up, tires spin, driver/cone bottoms out)

.....or, this could be complete bullshit. Please correct me if I'm wrong.   Wink

Bob
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #146 - 05/19/06 at 22:07:44
 
[quote author=John in CR  link=1145573673/15#28 date=1146245146]Bob,
 The HWK is not an HT subwoofer.  It is a great club cab though.  It simply doesn't do low enough to be good for HT.  As stated above, it was designed to roll off below 40hz.   [/quote]

hmm so who do we believe john or steve? 40hz or 13 ???
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #147 - 05/19/06 at 22:12:28
 
I don't have any means of measuring hz, but this thing is not getting NEAR that low. I've played sweeps a few months ago from 150hz, down to, ummm..... 20?.. 25???
Sweep, or more like 'steps' when one hz at a time. They trailed off badly, almost got QUIET below,.... umm, 40hz? Just about the time things started getting GOOOOODDD.


Bob

(I believe my ears)

I need to run the sweeps again, just for 'grins'.
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« Last Edit: 05/19/06 at 22:13:07 by Bob »  
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #148 - 05/19/06 at 22:22:25
 
call steve on the phone and ask him what the best way to implement the hwk into a ht system is.
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #149 - 05/19/06 at 22:47:58
 
60,

I appreciate your enthusiasm, but the HWK is not at HT sub.  In the good sounding aligment making use of the big iso chamber, the upper chamber (lowest tuned one) of the 15" version of the normal HWK is tuned to about 45hz.  If you put the driver(s) in the bottom baffle only (unbalanced sounding IME), the top is only tuned to about 35hz.  The alignment definitely allows for extension below port tuning, but none of the driver arrangements are going to give any kind of significant performance in the teens no matter what driver you put in them.  The HWK is for music.

With Bob's current configuration, the big chamber is tuned to about 19hz, and with the magnet in the top chamber and the cap on, it is tuned to about 47hz.  Bob, now that I've put the calculator to it, you should test the SQ and limits like this, call it the HWK-HT.  If you want to try 15hz tuning, you need to add another 10" to that 13.5" port OR you could leave the vent the same and mount the drivers as the top cap (14-16hz tuning).

Bob, if you can make the 6th order bandpass (ports top and bottom) work for you SQ and extension wise, that's probably your best easy thing to do, since the top chamber helps control excursion below tuning better than the ported alignment (driver open to the room).  

Put the top cap back on and try to integrate it with your mains and play some of those LFE tracks.  You may have gotten lucky and be done for now, at least until you build some new mains.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #150 - 05/19/06 at 22:48:52
 
Not a bad idea 60.
I'll tweek some more based on John's advise. I have faith the man can help. He seems to be focused on bassboy and my projects fairly intently. He's got MUCH more experiance and knowledge than I. He's also got a home theater, so he might just have the edge on LFE's for soundtracks vs. music.
I don't mind tweeking, but like J_Rock said, it gets old after awhile. Especially when I thought I knew something about audio/video, and as it turns out, I know just slightly more than nothing. Tweeking is free. Being of "average income", I can't justify the purchace of the "just buy the high-dollar piece and be done with it" philosophy.  :(


Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #151 - 05/19/06 at 22:53:47
 
Bob,

Check my post above, in case you missed it.  If you want to think of ports like air brakes on a truck, then below tuning you have a busted air line.
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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #152 - 05/19/06 at 22:55:02
 
Without a doubt the HWK will go that low.  Bob would just need different drivers that sweep more air.  and to lengthen ports.  The reason the HWK is a club bass cab is the tuning of the chambers, the top chamber and the bottom chamber are tuned signifiacantly higher than one would tune to get the really deep bass LFE channels contain.

(I would say the exact tunings, but then someone could easily copy the HWK design.  So Lets just say its too high for Bob's Subs to go low.)

As far as having two subs~
I think subs should be used for the really low frequencies.  From 10 to 80Hz max.  Thats 3 octaves.  Not a lot to ask of a main to go down to 80Hz.  And 3 octaves isn't alot to ask of a subwoofer.  SO as long as the subwoofer design gives clean extension deep and distortion free up top, there should be no need for two subs.

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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #153 - 05/19/06 at 22:57:12
 
[quote author=John in CR  link=1145573673/150#152 date=1148075627]Bob,

Check my post above, in case you missed it.  If you want to think of ports like air brakes on a truck, then below tuning you have a busted air line. [/quote]


this is an excellent analogy.  

Below a port's tuning in a normal ported box the Air behind the sub looses control over the sub's movements.   This is why You hear a klopping sound.  Below the port tuning, the ports no longer resist the Sub's motion so they flop around...

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Bob
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Re: hz numbers on a 15" 2 driver
Reply #154 - 05/19/06 at 23:05:31
 
[quote author=J_Rock  link=1145573673/150#154 date=1148075832]

Below a port's tuning in a normal ported box the Air behind the sub looses control over the sub's movements.   This is why You hear a klopping sound.  Below the port tuning, the ports no longer resist the Sub's motion so they flop around...

[/quote]


By that reasoning, wouldn't DEcreasing diameter of top port help regain cone control?

John, That's a lot to chew on. Didn't understand totally after reading the first time.  Signing off here at work, will re-read again in the am.

Bob  (THANKS ALL)
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« Last Edit: 05/19/06 at 23:07:41 by Bob »  
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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #155 - 05/19/06 at 23:07:31
 
Nope, decreasing the diameter while keeping the same length raises the the tuning of the port.  Above that tuning everything is okay, but below you loose control.


If you really want to know why a port losses control below tuning I am sure someone can explain, but Its really not important the HOW or WHY.  Just know that it happens.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #156 - 05/19/06 at 23:09:24
 
Knowing HOW or WHY would "help one master the outcome".

Remember, knowledge is power.   Grin

Bob
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« Last Edit: 05/19/06 at 23:09:48 by Bob »  
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #157 - 05/19/06 at 23:12:32
 
DAMMIT, just remembered, can't post at home.....  >:(

Talk to you all on Monday.

Bob
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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #158 - 05/19/06 at 23:16:45
 
Well alright then.  The way I understand it:

A Ported box is extremely alike to a sealed enclosure.  Only difference is there is a hole in a ported box that is deep enough to support a standing wave.  The frequency at which this wave will stand is based on the length and diameter of the port.  Above the frequency of this port, the box acts just like a sealed enclosure.  As you get closer and closer to the tuning frequency, the port begins to resonate.  The resonace results in a boost in output near the tuning frequency of the port.  

Below the tuning of the port, things go haywire.  They do this because below the frequency, the waves are too long to form a standing wave, and so they pass in and out of the port without any restriction.  Since the hole in the box no longer resists the air flow, the air cannot control the subs movement from the lack of pressure behind the cone.  So the sub becomes "unloaded" and is esentially acting as if it were in free air.  

At low power this has very little effect on the sub, but at higher power, the sub quickly begins to move back and forth farther than it is intended to do so.  Eventually leading to the sub reaching it's mechanical limit of excursion.  In other words, the voicecoil starts slamming into something.

Hows that?
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #159 - 05/19/06 at 23:29:11
 
Bob,

Something to keep in mind is that a little tweaking is very easy and realistically starting from scratch is going to require one of 2 things, 4 times the box size (which will at most get you 6db more than optimizing what you have) OR two smaller boxes plus as much power as your drivers can handle and Linkwitz transform circuitry (which probably won't net much SPL gain).  You could spend over $300/driver and get some extreme excursion drivers, but again your 2 will about equal one of those, so you'd need 2 of them to add another 6-8db to your existing potential.

Getting into the low teens just isn't easy without numerous high excursion drivers, not when you're asking for 100db+ down there.  That's why I haven't built a super sub yet even though I have lots of drivers.
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Adrian D.
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Re: hz numbers on a 15" 2 driver
Reply #160 - 05/20/06 at 17:37:05
 
i remember HBbass got pretty good results with the 10" version of the hwk, and steve's subs.
check the second page of the HWK support forum.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #161 - 05/22/06 at 11:54:52
 
Well,.. had zero play time this weekend due to deck buliding, and the death of a good friends wife.  Too much death recently on this forum.

John, how about Dan Wiggins design you mentioned on page 3, reply #34. 110db @ 11hz to 40hz. I've got the amp, I think I've got the drivers (not sure if he's referring to DVC's or not?)

I've got the space,...I think for a 14cu'  box. That'd be less than 2'X2'X4' I believe. That seems small.

Now, I realize there's a gap from 40hz to my bottom of my current mains.
But I see an option...
"buck-up" and spend some money, Use Dan's plans for the content below 40hz, with new drivers, use HWK for the content from 40hz and up. Use existing 2 channel amp to feed both subs.
Would this be an acoustic mess? Crossover nightmare?

OR,... Build Dan's box, suffer with the hz gap until new main/surround can be built.

Whadya think big guy?

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #162 - 05/22/06 at 19:27:28
 
Bob,

Sorry to hear about the problems.  It really sucks when others die.  On the bright side, when it's our turn hopefully it won't.

Dan said "more than 110db in-room".  It's essentially what you have now (with the top cap on) output-wise, but with deeper extension.  It's also exactly what I was talking about with HWKenstein by just adding the extension to your existing cab as previously outlined.  If you make the extension removeable, then you can have your cake and eat it too.
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #163 - 05/22/06 at 21:39:49
 
Ok, so I refered to post #66 on page 5. THAT is what I need to get lower hz, not nessesarily higher db.
Right?

I can accept the volume for the most part.  ???
But lower hz would be nice. I feel I'm not getting the most out of a movie if the soundtrack has material beyond what the equipment is capable of. The volume is the "cherry on top", as long as it has a decent punch. Your correct about teaching the youngsters bad audio habits. Not in the least, I'd hate to damage the frail little ears.
Bob
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« Last Edit: 05/22/06 at 22:16:32 by Bob »  
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #164 - 05/22/06 at 22:38:18
 
Bob,

That's the one and I think I had a post shortly after that talking about how to make it reversible.  Note that you will need to change the top port too to something close to Dan's recommendation.  The volume in that chamber net of the 3L for the driver and 4L or so for the port is a almost the size he recommended.

I think first though, try what you have with the top cap on.  Do your max test and SQ.  Experiment with lower tuning (longer ports) on each (4" in the case of the top one).  That higher tuning will get you higher max SPL than the big one and might just blend OK with your current speakers.  Even try a 10" longer bottom port for 15hz tuning, which may be low enough, although I think you'd be getting into high port noise territory with that long of a port.  

To check what 15hz tuning is like, you can also use your current bottom port length and mount the drivers in place of the top cap.  You wouldn't have the same excursion control (and max potential) that the 6th order BP (ported top and bottom) has, but it would definitely blend with your mains.  Easy conversion and easy change later to HWKenstein makes trying with the pretty box you already have make a lot of sense to me.  

If you want to go for the gusto, don't let me hold you back.  I've all but decided to give HWKenstein a go myself.  I just can't see building the 900L version of the Tower of Power that I've been discussing with Bassboy.  I might as well go sealed and use all my woofers if I'm going that big.  I change my mind on a daily basis.
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Gexter
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Re: hz numbers on a 15" 2 driver
Reply #165 - 05/23/06 at 04:59:35
 
[quote author=John in CR  link=1145573673/165#165 date=1148333898]Bob,
I change my mind on a daily basis. [/quote]

Really I would not know what thats like. LOL.
Grin Undecided Undecided Undecided Undecided
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Bob
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Re: hz numbers on a 15" 2 driver
Reply #166 - 05/24/06 at 15:22:07
 
Ok, John, thanks. hurdle #1 is just getting back in the room.

Havn't spent much time in there recently. Well, except for American Idol with the wife.  :)

I'm not smart enough to change my mind. It spends enough time time trying to reinvent the wheel.  ;) I believe it was DD that discussed the uncontrolled dribble that his brain continues to spew forth. Kinda like that.

Bob
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #167 - 05/30/06 at 15:45:47
 
Ok, John, I got some to spend some time in the cave. Preliminary "first" impression is the overall sound quality is improved (for HT use). bass is less boomy (in my room) more precise. Didn't go for SPL / drywall cracking bass. Happier with the 'kids listening level'.
However, when the kids arn't home and it's dad's turn with the controls, still lacking in the very low hz. I'm going to perform your tweeks when time allows.

Thanks again John.

Bob
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #168 - 05/30/06 at 21:34:28
 
[quote author=Bob in St. Louis  link=1145573673/165#168 date=1149000347] Didn't go for SPL / drywall cracking bass. [/quote]

why dyu want drywall cracking volume when your watching a movie?  i find the impact of correct tonality enough, a bmw door being shut or a body hitting the sidewalk from 3 floors accurately reproduced is more than satisfying.....2 mi? bmw door being shut @ 130 db would likely give me a heart attack....litterally.why the need for such excessive volume?
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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #169 - 05/30/06 at 22:50:41
 
As you go lower in frequency, Waves need to be much louder in order to sound equally as loud as normal thing we hear, human voices.  Meaning, a 20hz wave at 130db sounds as loud as a 4000hz wave 120 db.

Plus its really cool to have drywall cracking...
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #170 - 05/30/06 at 23:04:17
 
60, I'm not looking for the entire 2 hour movie being 130db. I do like my hearing just the way it is, and am not looking to start checking on the availability of audiophile grade hearing aids. My goal is for the LFE, and "superLFE" (to coin a phrase) to be just that 'little extra'. It may be slighlty unrealistic to have that spl with the hz I'm looking for (in real life). BUT, the theater going experience is'nt real life, in my book. The examples John and I have given as the "benchmarks" are: first person view inside an aquarium with a small child banging on the outside in Finding Nemo. The opening scene of Star Wars III when the fighters are flying amonst the big ships. And finally the cannon fights between the two 1820's era ships in Master and Commander (which, if memory serves, was YOUR recommendation in the other thread. Good movie too, thanks 60.) All of those examples are situations that most people in real life have never / will never be in. So there is no reference point. What does a mile long, 1,000,000 ton spaceship sound like, in real life, when it explodes?.... Well, nothing really if you want to be REALISTIC about it, since sound doesn't travel in space. But when I watch it on the big screen, I not only want to hear it, loud mind you, I want to feel it too.
We all know what the gental voice of a female vocalist sounds like when reproduced perfectly, or the pluck of a guitar string, and the whack of a kick drum. Even the slamming of a BMW door. I don't want to screw that up, BUT my main focus on this room is home theater first. (I know, I know, I'm on the wrong forum,... whatever. You guys have more audio intellegence than any other forum I've seen regarding home theater. AND nobody here is "better" than anybody else, one of my pet peeves.) So when I watch "TV", I have to turn the sub amp down just a hair, no big deal. But be warned,... if you come to my house to watch an action flick,.... by God, action is what your going to get!

Thanks,
Bob  ;)
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #171 - 05/30/06 at 23:04:48
 
J, I have been working with drywall and painting all week with no end in sight and let me tell you, sir, there is nothing fun about cracked drywall.
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« Last Edit: 05/30/06 at 23:07:06 by bassboy »  
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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #172 - 05/30/06 at 23:15:44
 
LOL. Maybe not if you plan on repairing it...


I would leave it and people would ask, "Whys your ceiling cracked?"  

Then I would be happy to reply "My Subwoofer is loud.  And I made it"
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #173 - 05/31/06 at 00:25:42
 
[quote author=Bob in St. Louis  link=1145573673/165#171 date=1149026657]60, I'm not looking for the entire 2 hour movie being 130db. I do like my hearing just the way it is, and am not looking to start checking on the availability of audiophile grade hearing aids. My goal is for the LFE, and "superLFE" (to coin a phrase) to be just that 'little extra'. It may be slighlty unrealistic to have that spl with the hz I'm looking for (in real life). BUT, the theater going experience is'nt real life, in my book. The examples John and I have given as the "benchmarks" are: first person view inside an aquarium with a small child banging on the outside in Finding Nemo. The opening scene of Star Wars III when the fighters are flying amonst the big ships. And finally the cannon fights between the two 1820's era ships in Master and Commander (which, if memory serves, was YOUR recommendation in the other thread. Good movie too, thanks 60.) All of those examples are situations that most people in real life have never / will never be in. So there is no reference point. What does a mile long, 1,000,000 ton spaceship sound like, in real life, when it explodes?.... Well, nothing really if you want to be REALISTIC about it, since sound doesn't travel in space. But when I watch it on the big screen, I not only want to hear it, loud mind you, I want to feel it too.
We all know what the gental voice of a female vocalist sounds like when reproduced perfectly, or the pluck of a guitar string, and the whack of a kick drum. Even the slamming of a BMW door. I don't want to screw that up, BUT my main focus on this room is home theater first. (I know, I know, I'm on the wrong forum,... whatever. You guys have more audio intellegence than any other forum I've seen regarding home theater. AND nobody here is "better" than anybody else, one of my pet peeves.) So when I watch "TV", I have to turn the sub amp down just a hair, no big deal. But be warned,... if you come to my house to watch an action flick,.... by God, action is what your going to get!

Thanks,
Bob  ;) [/quote]

seems like a lot of work just to capture the few super-lfe moments you reference, there are very few movies i will watch twice, master and commander isnt 1 of them.but i accept we all have our own particular madness, and now i know where yours is bob.i however have 2500 watts on my sub in my car Wink
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #174 - 05/31/06 at 01:40:24
 
60,

Maybe you should change your nic to 30andUp.

Why play it?  It's on the recording for a reason, to be played.  Even most cinemas can't reproduce it properly.  We can get there relatively cheaply and it's fun to try.  I don't think anyone wants to boost what's on the track, just play it back exactly.  Explosions are loud, often uncomfortably loud for me in the audible region, but the subsonic stuff isn't.

I can see a lot more reason to have a sub that does 110+db at 10hz, than a car that will do 200mph.  I'd love to have both, so I'll start with the sub, since it's performance will get more use and it's more economical.
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #175 - 05/31/06 at 01:55:10
 
60, have you ever been at a friend's house, or anywhere, really, and listened to a tune that you KNOW has low notes that your system can reproduce that theirs can't?

It's frustrating and when it happens to me I just ask them to please turn it off, silence is better.

The fact is that MOST people are missing the whole bottom third of their recorded material and they don't even know.  Most people wouldn't care if they did know.

WE CARE A LOT.  Once you realize you have been missing it you would rather throw out your recorded arts collection than live without it.  Try it, you'll see.
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« Last Edit: 05/31/06 at 01:56:42 by bassboy »  
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #176 - 05/31/06 at 12:23:33
 
60, The goal is to hear 100% of the artist intension. (ok, maybe slightly exagerated in the LFE's) I will watch quite a few movies more than once. Kinda like listening to the same CD/album multiple times. Granted your more "captured" when watching a movie versus having background music. It's much harder to see a movie traveling down the highway than listening to your tunes in a car.
You and I might possibly be cut from the same cloth, we both want quality, just slightly different situations.
Given 30 minutes alone (like when the rest of the family goes to the grocery store) I'll watch the first bit of Saving Private Ryan, battle sequence ect...
Just like the strictly audio guys here will sit and listen to a couple tracks of an album/CD, and not nessesarily the entire disc. I'm perfectly happy seeing "bits" of movies (at volume of course  ;D). Sure, given enough time I'd rather see the whole thing, and make a event out of it. It's my drug, my escape from reality for awhile. I'm sure everybody understands that.

Bassboy, I completely understand what your saying about asking others to turn it down. Nothing worse than listening to someone elses tunes at high volumes when it sounds like crap (and they're grinning because they think it's cool  ::))

J_Rock, I've though about having SLIGHT drywall damage thinking it's cool and telling others, "yea that's because of the sub I built", and not fixing it. But I'd rather not have any cracks if the truth be told.

Bob
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #177 - 05/31/06 at 12:56:53
 
looking forward to pirates of the carribean 2 Grin
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« Last Edit: 05/31/06 at 12:57:05 by 60ndown »  
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #178 - 05/31/06 at 12:59:15
 
YES!
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #179 - 06/05/06 at 13:23:00
 
Spent some quality time just listening to the system from various souces this weekend, and am thinking the factory setup in my Chevy truck sounds better/sounds more accurate than my HT set up.  >:(
And this was at 30 miles per hour with both windows down.
I'm totally at a loss.

I realise my drivers arn't great quality (despite the MSRP) but I was happy for quite awile. Have I gotten used to them? (probably)   Am I board with them? (I think so)   Is my desire to build some of the good lookin' design YOU guys come up with making me "think" they're worse than they really are? (I'm very sure)    Have my tastes been refined by YOU GUYS? (guaranteed)    Have I "worn them out"? (doubt it)

Frustration with lack of knowledge and lack of funds is setting in. DIY is my only alternative. Unfortunatly being ignorant is a severe handicap.  :(

I havn't spent any money on another hobby I've got, thinking it may all go the way of Ebay soon. Problem is, it's also my sons hobby too.  ???  That one's more frustrating than this one. Shouldn't be that way.

ohhh what to do,  what to do.....

Bob

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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #180 - 06/05/06 at 13:46:29
 
Bob, hang in there.  I've been interested in the subject for 20 years.  It's only the last 2 that have brought internet and SERIOUS learning.  If you asked me to build a box 3 years ago, it would have been manufacturer's spec ported because that's the only thing I knew.  At this point, I can't imagine ever building a ported box again (unless it's EBS).

All these ideas you are getting are going to start making a lot of sense and become second nature.

Sometimes it's ok to put a project on the back burner for awhile and try something else, but don't give up on it.

Remember that when tuning a box below resonance costs efficiency.  It's all a trade off - if it's tuned high it's loud but bottoms out with low notes.  If it's tuned low it's quieter but handles low material much better.

What exactly is wrong with your SQ?  Does it actually sound bad or just not loud enough?  Are the Xmech (excursion) problems gone?  Does it sound ok at lower volumes, and if so, how much power are you trying to cram in there?

Keep at it, it's a lifelong struggle but you have to admit, it's fun.
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #181 - 06/05/06 at 15:14:44
 
Bob,

Just get a flat screen LCD and DVD player for your truck, or forget the LCD and bring the projector and screen outside to do the drive-in thing.  You and the wifey probably aren't old enough to have been on a date to the drive-in.....Steam those windows up.

You have enough woofer for a good sub or pair of subs, but it sounds like you aren't happy with your mains and surrounds.  I hope you didn't have the mains going and set on "large" for your sub tests, because you could have blown something.  

If all equipment is ok, maybe you've just messed with the setup enough that things are out of whack.  Go through the receiver setup routine again.  Then listen to some music, stereo only, no sub.  If it sounds okay, proceed with the other channels.  Dial the sub in last.

With the sub, you may have to play around with the distance setting and XO point to blend it properly.  Keep in mind that the physical distance is only the starting point.  You've got group delay with bandpass alignments and ported alignments.  eg I'm using a ported sub temporarily while I decide on my long-term solution.  It's crossed in very low, since my mains go very low, and really only the port output comes into play.  Despite the 15ft physical distance, I found the best setting for the subwoofer distance is 30ft in order to blend seamlessly with my mains.

It's like any hobby that can be frustrating at times.  Don't lose hope, it can only get better, and it's a lot less frustrating than golf can be.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #182 - 06/05/06 at 15:17:23
 
[quote author=bassboy  link=1145573673/180#181 date=1149511589]What exactly is wrong with your SQ?  Does it actually sound bad or just not loud enough?  Are the Xmech (excursion) problems gone?  Does it sound ok at lower volumes, and if so, how much power are you trying to cram in there? [/quote]

Well bassboy, I'm may not be enough of an 'audiophile' to accurately describe the SQ. But it seems to lack the accuracy, the punch, the.... DETAIL.  It's not as "crystal" as my truck is. I've sat in the garage with the engine off, windows up (best case senario) listening to a few choice tracks, then took the CD to the HT room for an A/B comparison. The truck (factory system) is clean, clear, accurate, precise, a "pin drop" type of thing, know what I mean? The HT room seems less of all. Hard for me to describe. It may be a room treatment issue?? It's kinda 'muddy', not 'skilled' enough to determine if it's crappy drivers, or room treatments. I've though about playing with absorbers, but I've played with too many things (and spent money) that havn't worked out.
Am I bitching?

ok, continuing to answer your questions. It's not an excursion issue anymore, I've learned to turn the sub amp down when  certian material is playing. (Still want to do John's mods to the HWK)
Actually, I've learned to turn everything down. I was trying to make my system "run with the big dogs" when it apparently wasn't made to.  ::) So instead of analizing db's and super low hz, I'm more on SQ.

I've got three 'modes' I use the room. #1 When everyone's sleeping in the am I'll play games at volumes almost too low to analize. #2 Movie time with the family, no obscene volume here either, sometimes hard to analize SQ with the kids in the room. #3 Bob's time when everyone is gone, guess what happens to the volume/amp gain then. It almost sounds better watching a movie at too high of volume than it does at 'resonable' levels. I'm usually "going for the gold" then, Like I'm spl drag racing. Ok, I've learned my lesson. I've quit doing that (don't want to blow something up) So now I'm listening at levels (music and movies) that, may be on the high side by some folks standard, they arn't "stupid high". But it seems I'm loosing material at these levels.

hmmph.

Bob
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #183 - 06/05/06 at 15:49:18
 
[quote author=John in CR  link=1145573673/180#182 date=1149516884] bring the projector and screen outside to do the drive-in thing. [/quote]

LOL, I like that John. I've thought about that believe it or not. It would be great for parties.

The surrounds have been set to small since the indroduction of the sub.

I've started over on the receiver set-up so many times, I can't count. I'm convinced any more improvement made in the audio department won't be coming from the receiver. It's got to be drivers (crappy) or room treatments. I've thought about making some panels to play with. The DIY of the panels is as easy as it can be, however the more time I spend looking at room treatment stuff, the more I find just how accurate of a science it is. I don't want to just 'put something together' and see what happens. Done that way too much already, as I mentioned in the last post.  ::)

So,... Should I stop on the HWK modding? Concentrate on drivers, treatments, or rob a bank and buy toys from "Steve D's toy room"?

I'd like to do one thing right the first time you know?

Bob (not on any anti-depressents either  :-X)
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« Last Edit: 06/05/06 at 15:56:12 by Bob »  
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #184 - 06/05/06 at 17:58:59
 
So now bassboy is spewing forth more news, adding to the doubt already planted in my head.  ??? Over in the 'Help me HT' thread about amps dropping off below 30hz. Dude your killing me Cry I know just enough to doubt everthing I own.)
Dammit, life in my own little world was sooo happy when I didn't know shit!

Ignorance IS bliss.

All you guys are great.  ;D  Thanks for the words of encouragement, and all the help. It's greatly appreshiated [sp].

Hang with me, I'll stop whining.  :)
Bob
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #185 - 06/05/06 at 18:51:15
 
Don't worry about the whining, it's a frustrating game in the beginning.

Take it into perspective.  You read about this box that could make carpets levitate.  You thought, man, that's what I need.  You built it and found out that it truly does kick some butt but you find you are unhappy with the very low end.  This happens to everyone, I'm no exception, I just had a different box and it happened to me a long time ago.  Believe me, no one does ANYTHING right the first time.

So now you have a problem and people are firing solutions at you from all angles, people are disagreeing with the proposed solutions and you are getting confused and a bit ill at the thought of it all.

Taking the leap and building your own box was your first success, even if it was not the perfect box for your HT.  Listening to EVERYONE and sorting through the confusion and taking John's advice to heart is your second major success.  The guy clearly knows what he is doing.

So now you have a different situation but it's still not perfect.  You don't know why it isn't perfect, but realize this.  John provided the answer to the problem before you even told us what exactly was wrong.  Let me say again, the guy clearly knows what he is talking about.

The problem here is that the issues you are describing are generally not sub problems.  Punch, detail and accuracy of the overall system is defined by the mains, the sub and surrounds are just filler.  Please don't confuse this statement as meaning that the mains are the only thing that matters.

At this point, I would advise, as John has done already, that a good bit of tweaking is in order, and I'm not talking about construction.

First of all, strip the system down to the bare essentials.  Amp and mains only, leave everything else off.  Make sure the mains sound good before you continue.  Then add the surrounds and make sure they are doing their job.  Only at the end should you fire up the sub, taking into account that it may not be in the BEST spot.  You may have taken some time positioning it in the past but it is a different sub now and it's time to make sure.  If your listening spot is in a room null, the only cure is to move either sub or yourself or both.  As you move yourself or the sub, or both, towards the walls, the bass gets heavier.  Even moreso with the corners.

Understand that there is nothing wrong with your drivers, they may be inexpensive but they are performers.  Understand that it is pointless trying to recreate the car audio sound in the house.  You use different sources in car and home, and these different materials contain different frequencies.  Many may disagree, but I find it incredibly easy to make a car sound good but incredibly difficult to duplicate that sound in a room.  Especially a difficult room.  But you should know it can be done well.

Nobody said this was an easy game, especially when you are just beginning and making everything yourself.  But there is no guarantee that ready made equipment will sound any better in your room.  Everything needs tweaking, whether it involves speaker placement, level adjustments, listening position, room treatments, etc.  It doesn't ever end until you are happy with it all.  Which, by the way will never happen, you will always want more.

At this point you would be doing yourself a favor to make sure your mains are up the the job by themselves.  Do the car/room A/B test only with mains and see if the indoor clarity, punch and detail can keep up with the car.  If they can't, there is a problem with either the speakers, the placement of the speakers, or the room itself.  Go on from there, adding components back into the chain.  Once you have it sounding the best you can, download some mp3 sine sweeps to hear EXACTLY what your FR graph looks like.  You may have some big holes or overlaps at crossover points, sine sweep is the easiest way to find out and equalize without owning real measurement equipment.

At this point, the clomping sound of Xmech overextension is gone, consider this a victory.  But at the same time, remember that your system is just that - a system of many parts, each of which has their own job.  The whole job will never be done well if the separate parts do not work in unison.

Above all, remember that the "big dogs" usually have a system that is tuned to very specific frequencies for very specific purposes.  They choose the material you hear because not everything sounds good in their system.  They leave you with the impression that their system is perfect but you will never hear it's inadequacies, they won't let you.

Remember our friend Tapeworm, not happy with his HWK, stumbled across a big horn and it was perfect for him, certainly way louder, but we both know it isn't going to play well below 40 hz.  Sub 20 hz is a totally different ballgame  and is not nearly as easy.

So now, taken into perspective, you have chosen to try to recreate the HARDEST portion of the frequency spectrum, starting with very little knowledge and success, but you are slowly gaining both.  Give it time.
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DirtDawg
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Re: hz numbers on a 15" 2 driver
Reply #186 - 06/05/06 at 19:05:25
 
[quote author=Bob in St. Louis  link=1145573673/180#185 date=1149526739]..... sooo happy when I didn't know shit!

Ignorance IS bliss.

[/quote]
Ignorance is a blister.

Cure:
Loads of surface area, low tuned EBS with enormous port, too much power. Bi-amp to second cab if you need bass, in addition to sub bass.
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« Last Edit: 06/05/06 at 19:10:59 by DirtDawg »  
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #187 - 06/05/06 at 19:15:44
 
Bob,

I think you should hold off on the sub and decide on mains.  Then you'll know what range you need out of your sub.  So for now, leave the sub with the top off, making it a fairly compact, vented isobarik tuned to about 19hz.  You should be able to integrate it pretty well with your current mains and 105db without a rumble filter on Master and Commander isn't too shabby at all.  By the time you are ready to finalize your sub, some of us should have already tested these exotic TL type alignments we've been discussing.

The first place to start, as Bassboy mentioned, is your stereo mains.  Put your SPL meter to use and measure what you have.  Start a thread in speaker builders and include close-up picks of the drivers in the speakers you already have.  If you're lucky, the drivers are good quality, but are just implemented poorly.  That way you aren't starting from scratch.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #188 - 06/05/06 at 22:54:33
 
Guys Thank You. I've managed to have a pretty bad day at work (after all of my spewing) and you have brightened it. Having some focus and a goal is mui importante' (that's for you John) but having a few intellegent individuals guiding you is invalueable. Priceless.

bassboy, John - I'll listen to just 2 front mains to get an idea of SQ to ensure I have'nt misadjusted something. However, if memory serves these are 88db drivers. I have enough knowledge to know that these are turds about to be polished.

If you think, based on that number alone, I've got a shot at a successful "main mod" than I'll proceed. If need be, I'll find all of the specs. No, they don't have T/S numbers, just the basics.
If we go with the mods of my existing drivers, it sounds like my steps are these:

#1 isolate (disconnect) ALL drivers but one main, run sweeps at three feet from cone (mains are an MT arangement). I can't measure wattage, so I'll "pick a numeric referance point" on the display of the H/K receiver. Should I use stepped sweeps and record db's at given hz intervals? If so, what range and what interval to give an intellegent test?

#2 My next step is to take an enclosures apart, and find out what I've got driver wise. I'll post pics in the builders forum. Damn, I really need a digital camera.  ::) Gotta wait to 'burn a roll of film', then develop.  :'(

bassboy, that reply you just posted should be a 'sticky' at the beginning of the General Audio forum.  ;D That was excellent.

Bob
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #189 - 06/06/06 at 00:34:07
 
so you butcherd your beautifully designed hwk and now it doesnt sound good............imagine ??? your vehicle is balanced because someone wasnt trying to make it play 18 hz at full volume, thay made it play reasonably flat across the board. perhaps its time to restore your hwk to its 'designers' spek and start to enjoy again? seriously bob, for now, forget chaseing 18hz@130db and get used to flat response and all the joy that brings....even to movies Grin so what if you miss the occasional 18 hz rumble? you get EVERYTHING ELSE perfect.
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #190 - 06/06/06 at 02:09:36
 
Actually, the reason I recommended sine sweeps is because you don't need any measurements but your ears.  Start at 20 kz and it's a continuous signal down to 20 hz.  It should be equal volume all the way down, no peaks or dips.  If you use the computer to play the mp3 sweep, you can roughly estimate where you are on the FR line by the moving bar in the media player.  That's about all sine sweeps are good for, as they certainly will not tell you if the speaker is musical, even if the FR is flat.  If you want to go to the trouble of measuring specific frequencies with a meter, go ahead, but I trust my ears to tell me what's going on.  They don't have to measured one at a time either.  Sit in your listening position and play the sweep played by both mains.  If the signal is the same volume top to bottom, that's all you need.

Then it's time to measure musicality, which is entirely your preference.  This can only be done with your favorite tunes.  Come back at us with impressions - good, bad, coherent, muddy, etc.  Compare it to the truck, if you want, just about all of us know what a GM truck sounds like.

Never mind the main's driver specs, they don't make any difference.  The box is already built, all you have to do is make sure it pleases you.  Low sensitivity drivers are not bad, just a bit quieter.

And finally, 60, no one is disputing the fact that the HWK is a great design.  But Bob wants a home theatre sub.  So do I.  The HWK has a place, and will stomp the competition if it's used for what it was meant for.  But it is not an extremely low tuned HT sub, that's just the way it is.  Bob probably would have been further ahead to build EBS ported or huge bandpass or maybe even an Imp SO in the first place, but he didn't know.  We all agree with the fact that the HWK is a great design, ok?  But we strongly disagree with the idea that reproducing the lowest notes on our recordings (mainly movies) is not worth it.
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #191 - 06/06/06 at 03:13:07
 
Also, Bob never did report on the sub's SQ as it currently is.  All we heard was that it bottomed out at 105db playing cannon fire including very low frequencies.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #192 - 06/06/06 at 13:19:49
 
60, In the eyes of many, sure it's butchered. It doesn't sound good your correct. The reason it's modified is that in MY room, with MY situation, with MY equipment, it didn't sound good in the first place so I had nothing to loose. I'm not enough of a 'professional' to make any concrete statements, BUT it sounds like the famous "one note wonder" everyone talks about. It has been pushed and shoved, flipped, leaned, tilted, and twisted in so many configurations in the room trying to find proper placement it's not funny anymore. I actually thought about installing casters on the damn thing to ease in moving it.

As far as my truck being resonably flat across the board, it may be. But the board ends at several hundred hz too. It doesn't have to work too hard.

I've put 18hz@130db on hold. Not sure it's obtainable on a budget. How about 18hz@105db? Resonable enough for a workin' class man? I think I'd be happy with that.

As far as missing the 18hz rumble and everything else being perfect, well.... I don't think I've got much below, hmmm 30, 40hz?

You CAN'T tell me you have never been unsatisfied with your equipment. You've never tweeked? EVER? If you just buy and install it, then your either easily impressed or have enough money to get what 'fits the bill' the first time.
BTW, I noticed your signature a few posts back, not to be vain, but was that for me? ???
Thanks for the multiple boots to the testicles 60. Smiley How's that landscape project coming along? You didn't have any critters build nests in the ports of the HWK being outside did you? hehe

bassboy, I've got the sweeps, no problem there. Either need to 'burn' a CD, or run some wires from the PC, to the system to hear them. As far as the "quieter" comment about low sensitivity drivers, you mean there is no quality difference (in sound) between a 88db and a 95db driver? (tube rigs aside of course, since I'm SS)
You hit the nail on the head in your last paragraph about using the HWK for it's intended purpose.

I listened to several tracks last night with no sub. All four "smooth" jazz instrumentals that were clean, simple, clear tunes, no finger smoken' guitar rifs. Volume was a '5' on a scale to 10. (And I don't mean 5 on the volume knob) Nice and easy just loud enough to hear all the nuances. With no sub, it sounded fairly clean and concise. The soundstage is excellent (no thanks to the drivers, I give all the credit to the receiver for that) I was pointing out to the wife the subtle aspects of the tunes that she never heard before (getting her interested in SQ, trying to raise the WAF. It's working I think  ;D)

Let me back up a bit. I established early on in my tenure hear that my CD/DVD source is an XBox 360. (I'm sure most of you just leaned back in your chair, eyes rolling to the ceiling)
The songs we heard last night were either 'burnt' cd's of jazz, or songs that were originally from a 'factory' cd, stored to the hard drive of the 360. I've found no difference in SQ from a 'factory' cd playing on the unit, compared to the same song stored on the hard drive.
Now it seems to me that all of the clues add up to a bass problem. The kids were sleeping last night when the wife and I were listening, so I had no chance to let the system 'stretch it's legs' with the sub out of the mix. But it seems that the lower content is mudding things up. Now I see a few posibilities; crossover problem, sub itself (not being a good match with my room) room treatments, or finally, something in my rack doesn't like the LFE's?

hmmmm  ???

Bob
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Gex
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Re: hz numbers on a 15" 2 driver
Reply #193 - 06/06/06 at 15:15:08
 
Your chevy truck sounds better than your HT?
I have a suburban with cavernous rear quarters and really nice 6X9's I alse have some modded speakers in the dash with a center channel.
One pro high power deck and thats it. I was listening to organ ( church type) music on my trip this weekend.
It amazes me still. MY mobile version of the MG944. All I ever adjust is the imaging.
It is so well balanced overall that I will not mess with it. Its been the same for about 5 years.
this truck required the least work out of any vehicle I have ever had.

I can relate
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #194 - 06/06/06 at 15:21:58
 
And it's a factory system. 5 years old with 90k on the odometer.  ::)
Sitting in the sun, cold. Worst case senario for a driver. Imagine you were at 5`F on a cold winter morning and some A-hole cranks your knob to 7, expecting your best when your frozen.  >:(
And some how manages to sound great. (granted not audiophile, but great for an O.E. set-up anyway)

Bob
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #195 - 06/06/06 at 16:39:09
 
The sensitivity rating by itself simply means the speaker is a bit less loud at any given power level.  That's all it means and you cannot make any guesses as to good or bad sound based on this spec alone.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #196 - 06/06/06 at 16:48:51
 
Thanks bassboy, and here I thought I'd make it through the day without learning anything!  :)

Bob
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #197 - 06/06/06 at 17:54:08
 
Here's another bit to think about.  Any audiophile will tell you that the proper sub level is barely on at all.

Start by listening to the mains.  Slowly turn up the sub gain until you barely hear it making any sound.  Then turn it down a notch and that's your sub level.

I would not consider myself an audiophile and those levels are a bit too low for me, but try it and you might notice that the muddy sound your are describing is just way too much bass.

By the way, if your box is aligned exactly the way John told you, it should start getting strong around 40 hz  (on a downward sine sweep) and be satisfying down to at least 20 hz.  Are you sure it's exactly the way John told you?
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« Last Edit: 06/06/06 at 17:55:28 by bassboy »  
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #198 - 06/06/06 at 19:35:50
 
the thing is for me fellas, that of everyone that posts here i believe steve deckert is the most knowledgable. he has been designing and building for a long time (and not part time), i have built several of his designs (not modded) and they all did exactly what he said they would , basically flat to 20 hz and excellent sq, i have a test disk and there is very little, if any drop off until about 23hz? in my hwk, i have had it in many different positions (includeing the garden Smiley) and all it does is produce 'gobs' of great bass. i know from your posts that you all understand audio better than me, so i cant argue any specific points, but lets say this, if i had to build an aeroplane and actuallyfly in it), i wouldnt try to modd one, i would build a tried and trusted desighn that had carried many people many miles many times, and returned them to ground safely. which i believe is exactly what steve offers in his plans Wink ....except obviously his subs dont fly, but apparently they can 'levitate' rugs!
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« Last Edit: 06/06/06 at 19:36:26 by 60ndown »  
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #199 - 06/06/06 at 19:57:50
 
60, I don't disagree with a single thing you said this time.  But you are neglecting a few points that we have made.

Not every sub is ideal for every purpose.  For example, the low tuned subs we are planning would absolutely suck where the HWK excells.  Even more to the point, your HWK measures completely different in the garden than it does in the corner of a small room.  Don't tell me it doesn't, unless you live in some other dimension.

The proposed other solutions (EBS ported and huge bandpass) are also tried and true options, they just weren't offered as plans by Steve.  The only product in the Decware lineup that is going to do what Bob wants is the imperial SO, that's just the way it is.

And furthering your alalogy of airplanes, a stealth bomber is not going to help you much if your need is really for a passenger jet.  (Notice I equated the HWK with a stealth bomber just to make you happy.)

By the way, I would encourage you to measure again.  Unless you have an Imperial SO, I doubt very much anything you have built is hitting 20 hz flat.  They just simply were not designed to do that.  What you just described in your HWK assessment is an F3 at 23 hz.  We are talking about F3's below 15, which may not seem to be an incredible difference until you look at the exponential nature of the FR line.  To be fair, I have only tried a WO and Imperial, both with inadequate drivers, but common sense tells you that you need bigger boxes and lower fs drivers to do 20 hz flat.  The only reason the Imperial SO is flat at 20 hz (as it is theoretically too small as well) is that Steve is ingenius in his designs, no one is disputing that at all.
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« Last Edit: 06/06/06 at 20:08:40 by bassboy »  
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #200 - 06/06/06 at 20:42:39
 
OK bassboy, John gave me a couple ideas, we're trying the small/easy/cheap version first. If memory serves, here's the current configuration;
One hole is closed
Other enlarged to fit 4" PVC, I think it's 17" long
Drivers clamshelled in/on top baffle
Drivers out of phase
Amp is bridged (900W)
Top lid off, then on, then off, now it's on.

You know 60, I saw your mug on the other post. It's scary how much we look alike.

Bob
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #201 - 06/06/06 at 20:50:22
 
By the way 60, --"bass, the final frontier!"?

Do you really mean it?

Bob
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #202 - 06/06/06 at 21:01:36
 
[quote author=Bob in St. Louis  link=1145573673/195#202 date=1149623422]By the way 60, --"bass, the final frontier!"?

Do you really mean it?

Bob [/quote]

its a play on words with startreck (1st series) and my love of bass Wink

"captins log......etc etc.........................."
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #203 - 06/06/06 at 21:04:50
 
[quote author=bassboy  link=1145573673/195#200 date=1149620270]60, I don't disagree with a single thing you said this time.  But you are neglecting a few points that we have made.

Not every sub is ideal for every purpose.  For example, the low tuned subs we are planning would absolutely suck where the HWK excells.  Even more to the point, your HWK measures completely different in the garden than it does in the corner of a small room.  Don't tell me it doesn't, unless you live in some other dimension.

The proposed other solutions (EBS ported and huge bandpass) are also tried and true options, they just weren't offered as plans by Steve.  The only product in the Decware lineup that is going to do what Bob wants is the imperial SO, that's just the way it is.

And furthering your alalogy of airplanes, a stealth bomber is not going to help you much if your need is really for a passenger jet.  (Notice I equated the HWK with a stealth bomber just to make you happy.)

By the way, I would encourage you to measure again.  Unless you have an Imperial SO, I doubt very much anything you have built is hitting 20 hz flat.  They just simply were not designed to do that.  What you just described in your HWK assessment is an F3 at 23 hz.  We are talking about F3's below 15, which may not seem to be an incredible difference until you look at the exponential nature of the FR line.  To be fair, I have only tried a WO and Imperial, both with inadequate drivers, but common sense tells you that you need bigger boxes and lower fs drivers to do 20 hz flat.  The only reason the Imperial SO is flat at 20 hz (as it is theoretically too small as well) is that Steve is ingenius in his designs, no one is disputing that at all. [/quote]

Using musical instrument woofers (ex. PEAVEY BLACK WIDOW) you get tight full accurate bass from 200 down to 40 HZ. Using subwoofers you get big warm full bass that can on command create Subsonic pressures lower than 20 cycles.  
??? Roll Eyes Cheesy Grin Wink Kiss Embarrassed
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #204 - 06/06/06 at 21:23:43
 
60, I was trying to ---  :-* --- with the 'frontier' comment, you didn't fall for it.  :)

I've quoted that very same line directly from the "pretty picture page" of the housewrecker ad.

It's been shot down many times. much to my dismay.
Steve hasn't devulged [sp] how he got there from here.  :'(

You never answered my question about your HWK and the critters.
You got pics yet of the landscape ?

Bob
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #205 - 06/06/06 at 21:32:42
 
Where in there does it say it's flat to 20 hz?  My imperial is flat to 40 hz, but you better believe it can create subsonic pressures lower than 20 cycles.  Let's see some FR graphs, please.  With real drivers in real conditions, please.  I don't post pictures, but if you want, I will gladly link to a spot showing a FR graph of my current unfinished (almost unstarted) project, clearly showing predicted response flat to about 18 hz in a box which is probably smaller than the HWK (but I assume not capable of anywhere near the brute SPL).  That's using the Dayton Quatro, the Series II's 4 ohm brother.  And that's before I start modding it Jensen style for a killer low end.

Measure your box, my friend, get out your meter and do some charting but be sure to mention where it was measured - outside, small room, corner loading, etc.  I'll guarantee both our boxes will sound good, so the differences will be pure SPL and FR.  You have chosen higher tuning and higher SPL, I choose lower tuning and lower SPL.  (Although I'm hoping for 95 db at 1 watt, shouldn't too far from yours)
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #206 - 06/06/06 at 22:01:30
 
my only measureing tools are my ears, what critters?

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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #207 - 06/06/06 at 22:06:49
 
Nice yard, VERY nice fence!

Do your ears fall off below,.... um... ?? How low?   ???

Bob
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J_Rock
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Re: hz numbers on a 15" 2 driver
Reply #208 - 06/06/06 at 22:11:13
 
research normally says 20hz.  But I feel (after reading some articles on ultra low high SPL sound, that we can hear below that.  It's just that our sensitivty to these sounds drop off at such a large rate, the sound level required for us to HEAR 15 hz is extremely high.  Normally we feel these sounds before we hear them.

An excellent example would be the large Barges that float down the Mississippi nearby.  When I am laying in bed at night I can hear them.  And while I listen I can count the peaks in the sound.  The frequency basically.  Now wether this is the beat effect or actually a wave I am hearing is still to be known...
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #209 - 06/06/06 at 22:17:21
 
Ok bassboy, way back on post #201.
Does that give you the information you need?

J_Rock, I've heard (no pun intended) that humans can hear down to 20 just like you have heard (ok, pun intended that time) but I agree with you, that we can hear well down into the teens.

Bob
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #210 - 06/06/06 at 22:36:55
 
Bob, I have to admit that I haven't done the calculations on any of the suggestions John and others have posted.  I have full faith that if John says the box is tuned at 19 hz, then it is.  If you chose the right length of port, it should perform as described.

But just if you want to be sure, plug the driver's specs into WINISD (it even allows isobaric loading as an option) and model the suggested box.  Then go to the next tabs and change the box size and port length to your box size and port length.  What you see in WINISD is what you should hear in your room, but with a bit of room enforcement on the low end, and even more for corner placement.

Keep fiddling with WINISD until the curve looks like what you want to hear, it's fun and free.

Try playing with flared ports too, it's good for you.
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« Last Edit: 06/06/06 at 22:38:16 by bassboy »  
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #211 - 06/06/06 at 22:39:40
 
And if you can't find ALL the specs, you have to download the manufacturer's driver specs in pdf, I found out they are all there.
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #212 - 06/07/06 at 01:55:30
 
The bottom 2 chambers of Bob's box nets to about 155L (net of driver and port).  With the 13.5" long 4" port the tuning is just above 19hz, but with that corner placement he's getting an effective length of over 15".  With the isobarik loading, the drivers are acting the same as a single driver in a 310L box.  It's closer to an EBS type alignment but with a small box.  Even though he could lower the tuning, the port would turn into a problem because it would get so long.

So no Bob's box isn't flat to 19hz, but the few db sacrifice for the added shelf of extension is offset by some room gain.  In room, Bob should be pretty flat down into the upper teens even though his layout doesn't give him maximum room boost.


Bassboy,
I'm pretty sure that 95db on 1 watt at 20hz is a pipe dream (excuse the pun).  I think only a giant bass horn or multi-driver rig will do that.
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #213 - 06/07/06 at 02:10:09
 
Bob,

How about if I throw you a real curveball.  If you only connect 1 of the voice coils on your drivers, it is almost identical to the Dayton IB15.  That means you also have the capability of going OB or IB with those drivers and even get the added advantage of fine tuning the sound with RDO (Resistive Damping Operation) using a variable resistor across the unused terminals.

What's on the other side of the wall behind your screen?
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #214 - 06/07/06 at 03:52:02
 
The Tower of Power does 95 db.  My traditional design models at 93 in open space.  With Transflex loading, corner loading and room gain I am hoping for 95 db at 1 watt at least way down low.

I would be thrilled with that level, and I am hoping for that much volume but we'll see.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #215 - 06/07/06 at 12:45:10
 
John, my drivers are Single Voice Coil...

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-130&CFID=4954...

The depth of the surrounding cabinets is about 18", the back of the cabinets are about 1 1/2', slightly less from the sheetrock wall. The thickness of the screen is about 1". The screen is "torsion panel" construction, like a cheap interior hollow core door. The distance from the back of the screen to the wall behind it is right at 30". Currently the space is storage. The screen is hinged at the top, and 'flips up' like a giant car hood. My original plan back there was to put shelving for storing 'stuff', but just havn't gotten around to that particular project. So the 'stuff' is just sitting on top of the cabinets.

So yea, I've got plenty of space back there, cubic feet wise. But that may be irrelevant if were not talking about the correct drivers.

Bob
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #216 - 06/07/06 at 18:26:08
 
Bob, overlooking the DVC issue, the end results are not irrelevant.

The important thing when designing EBS ported is the box and port tuning.  As long as the box and port are tuned to work together, the driver is the only responsible for putting out whatever it can at the requested frequency.

The box will output whatever sound the driver presents it with at the box's tuning frequency.

The problem comes into play when you tune the box and port WAY out of the driver's range, which you haven't.  The cost in that case is sensitivity, because the driver is struggling to make sound way below it's resonance and we've all seen the FR graphs that show heavy rolloff around fs.

I strongly urge you to play with WINISD, you'll learn more there much more quickly than anyone can explain anything.  It's an excellent visual tool that you can experiment with.
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« Last Edit: 06/07/06 at 18:27:15 by bassboy »  
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #217 - 06/07/06 at 19:58:24
 
bassboy, I've played with WinISD, it is pretty cool. Somewhere around page 3 or 4 of this thread I mentioned to John, that the program was giving me the message, "this version can't perform that task, you looser". I guess I need "PRO" version?
It is fun to play with though.

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #218 - 06/07/06 at 20:13:54
 
Bob,

It would be nice to know once and for all which drivers you have.  Back on page one you gave us a link to these, which have 15mm of Xmax (that's almost a 6db difference at the bottom end):  http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=295-190

Let's get on the same page before proceeding.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #219 - 06/07/06 at 20:38:11
 
John, I'm sorry. Your reading post #3 which is the one I said I have Part#295-190 (DVC's)
On post #8 I apologized, corrected my mistake by saying I have Part # 295-130 the single voice coil.

I though about deleting/modifying post #3 so thing like this wouldn't happen. I figured I'd leave it alone since it would "F"-up the 'story line'.  ::)
I didn't think by now, anyone would have gone back that far, or would have read further down and see the correction.

Again John, I'm sorry.
I do sincerely Thank You for the time you've spent with me.

Bob
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #220 - 06/07/06 at 20:54:22
 
Bob, WINISD cannot model the HWK or 6th order bandpass but it does very well with isobaric vented, which is what you have.

I'd go through the motions but I don't post pics so it's meaningless for me to do it.
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #221 - 06/07/06 at 21:20:05
 
Bob,

I think we're back to where you should give a good listen to what you have (drivers in top baffle clamshelled, one bottom port blocked, the other with a 13.5" or so long 4" port.  I think with the top off will be easier to blend with your mains but check it out, since the top on gave you better control over excursion.

Then play some of your DVD chapters with the sound at a good level overall and note whether you're getting pretty good oomph on your LFE's.  Keep in mind that later you can split the drivers up and put each in a box twice the size with the same tuning and get the same sound but +6db in potential.  You can also add a rumble filter at say 15hz which will give you more potential at 15hz and higher.  With only 8mm of excursion, I think you should forget about going lower than 15, but don't worry there's plenty of feel in the LFE's 15hz & up.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #222 - 06/07/06 at 22:28:19
 
John, I don't know where we're at now in the hz department, but I think I'd take the 15hz/rumble filter idea over the +6db gain since I'd have to build two boxes twice the size of my existing one to get there.
I'll take bassboy and your suggestion first. Remove some wires, listen to the mains then slowly add wires/equipment and gentle tweek along the way.

After I do that, I think I'll play with room treatments.
This is cheap/easy, don't laugh if it's a dumbass idea.
Take all of the cushions from the sofa's / loveseat's from upstairs furniture and line my walls with the cushions.

I've got to think that the room is playing into this. Despite how much time/effort I put into the room (with acustics in mind) that it turned out good enough not to need SOME form of absortion/diffusion.
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #223 - 06/07/06 at 23:17:54
 
If you want to see what bass traps might do, haul a couple of mattresses down there too.  Are the recessed areas on the ceiling in front of the seating area reflective or do you have acoustic tiles up there too?

BTW, the rumble filter would be needed with the 2 box approach as well.
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #224 - 06/07/06 at 23:34:03
 
mattresses on the celing? man alive, i laugh at myself sometimes trying to move my hwk and other subs, im sure they weigh in excess of 100lbs and awkward as a dead elephant . but im sure i would collapse into a ball of hyseria trying to fix a mattrress to my celing, bet the wife would love it 2 Roll Eyes
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #225 - 06/07/06 at 23:39:53
 
60,

You must get in trouble with the wife all the time misinterpreting what people say.  Mattress on the ceiling?  :'(
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #226 - 06/08/06 at 14:25:57
 
60, "AFRS" in the other 'active' HWK thread just told me the HWK is 140 pounds. (10 stones BTW, just in case that's your form of measurement.  ;))

John,  mattress is a good idea. I've thought about that, but I'm too lazy to drag a "califorina king" mattress down a flight of stairs.  ::)
Might rob the kids crib mattress (but it's plastic coated)
Or my son's 'twin' mattress  ;D

Cieling tiles are USG 2X2 acoustic, (very heavy compared to the cheap/standard white one's) They've got a very agressive texture on them.

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #227 - 06/08/06 at 15:41:49
 
Bob,

I was just making sure those recessed boxes weren't highly reflective.  Is it a basement?  If so, which walls are concrete?  Sure room treatments can always help, but from the photos it doesn't look like something I'd be in a rush to blame.  Unless you have some parallel concrete walls creating havok with room modes, you can throw room treatments under the header "fine tuning" on your list.  A 20-200hz tone sweep, can tell you if you have mode problems.  That will also reveal any holes in response with your sub/mains integration.  

I was asking what's behind that wall in front, not behind the screen.  Can't put a sub behind a screen anyway...too much air movement.
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #228 - 06/09/06 at 02:22:19
 
[quote author=John in CR  link=1145573673/210#224 date=1149718674]If you want to see what bass traps might do, haul a couple of mattresses down there too.  Are the recessed areas on the ceiling in front of the seating area reflective or do you have acoustic tiles up there too?

[/quote]

cmon it was a fair misinterpretation? first matresses get mentioned and then the celing?
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #229 - 06/09/06 at 02:39:29
 
Technically, mattresses on the ceiling would work for higher frequency bass, at least to some extent.  Placing them standing up, across a corner, however, would probably get a lot more mileage out of them, and work on a broader range of frequencies.
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #230 - 06/09/06 at 02:45:18
 
60,

Are you sure you aren't from Mississippi?

Those of us from Louisiana thank God on a daily basis for giving us Mississippi.  That way someone else gets to be #50 in almost every category. Grin
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« Last Edit: 06/09/06 at 02:47:16 by John in CR »  
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #231 - 06/09/06 at 12:20:18
 
John, it is a basement. 3 walls are concrete. Front, (behind the screen), the Back, and right walls are your standard basement foundation walls. Standard 2X4 walls with insulation. The only wall that deviates from the norm is the back wall. The drywall is somewhere around 8" or 9" from the concrete. This was done so I could avoid the various ugly "drywall framed boxes" people use to 'encase' the plumbing. I wanted a cleaner look. All walls in the basement are insulated with 'the usual', including interior walls.

Ok, who's comin' over to help with the mattress installation?  :-/ I'm going for all walls, floor and ceiling.  :-*

Ok, not really.

Bob
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« Last Edit: 06/09/06 at 12:21:40 by Bob »  
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Gex
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Re: hz numbers on a 15" 2 driver
Reply #232 - 06/09/06 at 13:09:10
 
Hey 60 don't feel bad about being 50.
Canada is the state that Americans did not want.

Thats a joke. in case  put anyone in a crank.

Funny you should mention the mattresses ( not the ones on the ceiling) I have a heck of a time getting my wife to throw out old mattress. maybe I could convince her to recover them with nice fabric and store them were the stereo is. Then I could get the stupid things out of my office.
Its so quiet in there I can can't hear myself think and I have to, or I don't think.
could be the reason for the last 100 or so posts  :)
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #233 - 06/09/06 at 13:18:27
 
Line your walls with old mattresses from the "junk store", saves money on drywall. Saves time on mudding the joints.  ;D
And just think, NO PAINTING!

Bob
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ado420
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Re: hz numbers on a 15" 2 driver
Reply #234 - 06/09/06 at 16:24:00
 
[quote author=Gex  link=1145573673/225#233 date=1149854950]Hey 60 don't feel bad about being 50.
Canada is the state that Americans did not want.
[/quote]
Really?
Because I always thought Canada was the state for Americans that aren't liked amongst other Americans  :D
Except for Alaska, that's an even further, more boring, exile.
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ado420
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Re: hz numbers on a 15" 2 driver
Reply #235 - 06/09/06 at 16:25:42
 
[quote author=Bob in St. Louis  link=1145573673/225#234 date=1149855507]Line your walls with old mattresses from the "junk store", saves money on drywall. Saves time on mudding the joints.  ;D
And just think, NO PAINTING!
Bob [/quote]

Ya, you don't have to paint because someone already beat you to the punch  :)
That's why it's in a junk store
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #236 - 06/09/06 at 16:56:56
 
Bob,

You're getting some bass trapping with those interior walls over the concrete walls, but they're probably all tuned the same.  Next time you can incorporate a panel bass trap design into the construction at essentially no cost.  I did that in my room and my entire room is a giant bass trap tuned to a very wide range of frequencies.  I don't need any additional bass treatments.  Your room probably isn't too bad at handling bass either.  A LF tone sweep will tell you a lot.

How much air volume do you think is enclosed with that back wall?

How difficult would it be to move that front cabinet/shelf unit away from the front wall?
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #237 - 06/09/06 at 17:32:10
 
[quote author=John in CR  link=1145573673/225#231 date=1149817518]60,

Are you sure you aren't from Mississippi?

Those of us from Louisiana thank God on a daily basis for giving us Mississippi.  That way someone else gets to be #50 in almost every category. Grin [/quote]

i must be number 51, i have no idea what you just said.
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #238 - 06/09/06 at 18:07:32
 
60,

I thought you were changing your name to 40nUp.  You understand that one don't you?
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #239 - 06/09/06 at 18:14:20
 
[quote author=John in CR  link=1145573673/225#237 date=1149868616]How much air volume do you think is enclosed with that back wall?

How difficult would it be to move that front cabinet/shelf unit away from the front wall? [/quote]

Are you looking for the volume behind drywall including the 4" insulation, or volume between back of insulation to the concrete?

Horrible PITA to move cabinets. Don't know if it's possible with the way the screen attaches to the wall. (wouldn't have a wall to fasten to anymore if it's moved out)

Bob
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« Last Edit: 06/09/06 at 18:15:53 by Bob »  
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #240 - 06/09/06 at 19:40:01
 
[quote author=Bob in St. Louis  link=1145573673/240#240 date=1149873260]Are you looking for the volume behind drywall including the 4" insulation, or volume between back of insulation to the concrete? [/quote]

If it's less than 100cuft don't worry about it.  If it's more, then approximate total volume behind the drywall.

Quote:
Horrible PITA to move cabinets. Don't know if it's possible with the way the screen attaches to the wall. (wouldn't have a wall to fasten to anymore if it's moved out).


I was hoping just a handful of screws holding the whole unit to the wall.  Move the light fixture on the right.  Move the cabinet unit out 18-24", and build a new wall with the airspace behind to house 1 or 2 IB manifolds.  Then just replace one of the panels with a grill to vent it into the listening area.  You sub would be out front where it belongs.  Extreme extension and output is easy.  No worries about integration with mains up to 80 or 100hz.  Your projector can move back and you get a bigger image ratio, and no big ugly sub to hide.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #241 - 06/09/06 at 21:12:34
 
[quote author=John in CR  link=1145573673/240#241 date=1149878401]If it's less than 100cuft don't worry about it.  If it's more, then approximate total volume behind the drywall. [/quote]

Without being at home, and the ability to measure the wall, I'm at a handicap. Hears a close guess. Under the 'cove' the wall is about 7' tall, we'll call the drywall .75 feet from concrete, and wall is about 20 feet long. I'd call that 105cu' which sound close enough to need an accurate measurement. I'm assuming an IB needs essentially no 'sealing' in the cavity the magnet is in.? The cavity between drywall and concrete is 'open' to all sides but the floor. It's as sealed as a 2X4 could be when next to concrete.

I really like the idea of an IB in the screen wall ( Yea, I've seen "The cult of the Infinitely Baffled". Cool stuff! )

When I started this project, I had never heard of IB.  ::)

Man that would be a huge undertaking, dealing with moving the screen and cabinets.

        l
        l
COVE \/    X         X         X joists X        X         X
------------+-------------------------------------
               l l                   ceiling tiles /\
               l l                                   l  
__________l l
                 l  <----- screen
                 l
                 l
                 l                      seating ------->
"open area"   l
                 l
-------------l
                 i
                 i
                 i
 cabinets     i
                 i
                 i
                 i
                 i                                 floor
------------------------------------------------------

Ok, the 'cove' is very permanent. Never to move. The "+" sign is the hinge for the screen (actually on the facing wall of the cove) If I pull the screen out, even a fraction of an inch, I'd have to 'reinvent the wheel' attaching it to something. Dealing with the tiles, and joists above to hang it from the ceiling instead of a wall is a bigger PITA than I think I want to get into.

Now the back wall,... I'm wide open.  ;D

Bob
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #242 - 06/09/06 at 22:59:57
 
You got me thinking John.   Smiley

Talk to you Monday. (here in the 'upper 50') Don't know what time it is there.  :P

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #243 - 06/09/06 at 23:26:03
 
IB just means the front radiation is kept separate from the rear radiation and the rear air space needs to be of sufficient volume that the driver cone operates like it is in free air.  The typical recommendation is 8 times Vas, but you can get away with less.  eg For the IB15 driver Dayton recommends at least 15cuft of box volume for each driver (less than 1.5xVas).  How well the airspace enclosed by the rear wall can be used for IB will depend upon how freely the air can flow in that enclosed area.  The drivers you have aren't suited for IB use anyway, just trying to help develop a good plan when you are ready to upgrade.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #244 - 06/12/06 at 17:19:27
 
John, I think two things have helped my rig.
#1 Your advise on the sub. The tweeks have helped. I've played with some of those car audio bass cd's (you know, the woofer torture discs). This sub could be used for a room fan. The air coming from the lower port is amazing (scary actually). WITH NO KLOPPING.  :D

#2 My maturity level. I've turned down the overall receiver/surround volume, and turned the sub amp up, quite a bit actually. I suppose I was so interested in the HT "escape" that I thought the entire experience had to be loud. Like a good song you crank up. (However, a 2 hour long cranked up movie leads to fatigue.) But was still looking for the 'punch' from the sub. Well, at that volume, the sub was already at 90%. Not much headroom left. So, turned the receiver down, sub amp up. Gives it the nice little suprise when the movie requires it. Didn't really change placement so to speak, but twisting it on it's axis so the waves have to take a different path has helped somewhat.

I guess I'm an official member now of the housewrecker club. One of my favorite cocktail 'hurricane' glasses I got from Bubba Gump's Shrimp Company in Chicago broke.  ::) I truly had mixed emotions about that one. Pissed that I broke it, but had an uncontrolable grin as I walked past my wife to get the vacuum cleaner...... Thinking to myself as I cleaned the broken glass, "Yea, I got me a badassed sub, I can break shit now."

I'm beginning to realize some of my unhappiness with the system is due to me. I've always had a problem with wanting to make something that works perfectly fine, better. We all know my setup would not be considered audiophile grade. I hear you guys talk about your systems knowing mines nowhere close. Man, I can't imagine how some of your systems sound (charlieboy's, Mr. C's ect..ect..). Granted they're listening rooms, not HT, but there is no law that says you can't have both. I guess knowing that there is something out there that's sooo much better acoustically than what I'm hearing from mine is what my biggest problem is. I'll never be happy.  :(
I'm not at all embarrassed about my system, I'd show it proud to any of you guys. Knowing all the while your probably thinking, "this sounds like hell. I can't wait to get back to MY room". But proud none the less.
I could stop on the room right now, never tweek another thing and be pretty happy with it. I'd continue to have friends/relatives over and show it off. BUT, I know myself, and will continue to tweek/complain/modify/spend money/bitch untill I'm blue in the face.

So John, as far as your comment about being ready to upgrade,.... I'm always ready (just not ready to move walls yet  ;)) ... you just keep those radical ideas coming. I'll build 'em...
Can't wait for you and bassboy to design that W.M.D. your planning.   Smiley  I'd build it, as long as the drivers is'nt super high dollar.

Bob

EDIT- just proofread after posting, apparently the website censored me when I wrote "c0cktail", it replaced it with thingytail!? ... WTF? a totally innocent word censored by a website.  >:( (had to use a zero instead of an 'o' to get it to work that time.) Apparently "it" doesn't have a problem with me using other 4 letter words though.  ::)
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« Last Edit: 06/12/06 at 17:31:03 by Bob »  
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #245 - 06/12/06 at 19:46:54
 
In an effort to further educate myself (surfing the net) I ran across this...

Specifically look for the clock, and the jar of rocks.

http://www.machinadynamica.com/

I wasn't feeling bold enough to start it's own thread.

Bob
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jj420
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Re: hz numbers on a 15" 2 driver
Reply #246 - 06/12/06 at 20:28:44
 
for such a "popular" product, that clock has very little to back it up.... there's not even a white paper on it, I am not certain a passive device such as this could actually improve the sound in a room.  I would have a much easier time believing it if there was more to digest on the site than some reviews of questionable objectivity, along with the alway suspect comments from "customers"

The pebbles on the other hand, I can see those working, I always weigh my speakers down with something, helps the definition a little.  At the ame time, a sort of " phase plug" in corner helps to break up refractions in these problem areas.

Magic rings, stage expanders, isolation platforms, this may show my ignorance, but the site is either a snake-oil cart, or a shop out of AD&D...

and all of it at bargain basement prices!!!! I cant wait to give them my account number HAH

almost always skeptical
JJ
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #247 - 06/12/06 at 20:58:29
 
I understand the principle of weight on a speaker enclosure, but the ounce and a half the glass jar of rocks provide wouldn't do didley squat. (except rattle and buzz).

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #248 - 06/12/06 at 21:12:52
 
Bob,

I thought you were in St Louis.  I ran accross a Missouri audiophile group on Audio Circle and it was filled with nothing but "believers".  Since when did Missouri go through the gross transformation away from being The Show Me State.  If it sounds too good to be true, guess what, it is too good to be true.  

You want a jar of colorful rocks, fine buy a jar of colorful rocks.  You want to buy a digital travel alarm clock, buy one.  You want to separate you rig from vibration with weight and springs, fine, learn the math and do it right with the appropriate mass and springs, just don't go out and pay $25/ea for 25cent springs.  In any other business, vendors like that end up in jail for fraud, yet audio welcomes them with open arms.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #249 - 06/12/06 at 21:44:42
 
John, I've read some of your conversations with my geographic brethren. Funny stuff. (Although not funny for those involved)   Tongue

Yea, Missouri IS the 'show me state", but I didn't need anyone to 'show me' those things.  ::)

I've been trusting (nieve) before, but that's just stupid. Anybody that buys that... well, you know.

Hey John, do you have any pics of your setup?

Bob
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #250 - 06/13/06 at 18:14:03
 
Ok, I want to put a Deathbox INSIDE of a Housewrecker, then put the Housewrecker INSIDE an Imperial, Then put the Imperial in the back of my truck. What would that sound like? Should I install a camper shell on my truck for more gain?

Bob  :-/

By the way, I took pics of the face of my Niles, then disassembled the cabinets and photo'd the inside. Have to develop the film to post.  ::)
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« Last Edit: 06/13/06 at 18:17:22 by Bob »  
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jj420
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Re: hz numbers on a 15" 2 driver
Reply #251 - 06/13/06 at 19:33:13
 
[quote author=Bob in St. Louis link=board=Housewrecker;num=1145573673;start=240#251 date=06/13/06 at 12:14:03]Ok, I want to put a Deathbox INSIDE of a Housewrecker, then put the Housewrecker INSIDE an Imperial, Then put the Imperial in the back of my truck. What would that sound like? Should I install a camper shell on my truck for more gain?
[quote]

outrageous man...

lets see, theoretically the two tunings would average the output from the db, yeilding two 'smaller than a normal HWK' spikes, which would in turn be amplified by the imperials horn...

so the system would have a fairly restricted output (low efficiency), likely resembling the comb effect of voight pipes, except distributed across the imperials response curve instead of a flat line.  Likely this would sound like @$$-mike + a long stairway, but with excellent power handling...

I think you were kidding though...  but the camper shell would help the gain a bit, by lowering it, that would be your only hope of achieving decent loadiung of the horn

I still think you are kidding, but a useless post is never truly appreciated until it is justified by an equally useless response.

JJ
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #252 - 06/13/06 at 20:41:22
 
[quote author=jj420  link=1145573673/240#252 date=1150223593] I still think you are kidding, but a useless post is never truly appreciated until it is justified by an equally useless response.
JJ [/quote]

Yea, I was joking. I was amazed at the amount of threads dedicated to fitting a home sub into a vehicle. Had to add my own flavor. Didn't want to trash someone else's thread, sooooo,... naturally had to trash my own.  :)

Thanks for the quick response though. Shame our last two post were useless (you were correct JJ)

So, are you board at work too?

Bob
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #253 - 06/19/06 at 19:14:12
 
Ok. B.S. aside. I've got pics and numbers. (Pics of surround drivers to be posted on webshots later today. Hopefully)

John, I played with some toys over the weekend. I have db numbers from 1 meter away from the bass of the sub at a hz range from 90hz, down to 10hz. ( yea, 10hz   Grin ) in 5hz increments. The first column is db's, second and third columns are hz's with the top cap on, then removed, respectively.
     cap    cap
     on      off

DB - HZ  -  HZ
90 - 110 - 110
85 - 112 - 110
80 - 115 - 111
75 - 117 - 112
70 - 119 - 112
65 - 119 - 112
60 - 117 - 112
55 - 113 - 109
50 - 109 - 106
45 - 109 - 107
40 - 109 - 107
35 - 109 - 108
30 - 109 - 108
25 - 108 - 107
20 - 105 - 104
15 -  94  - 97
10 -  88  - 96

With cap on (middle column)--Imagine a graph, (from right to left) you could see a small climb, to a peak of 119 between 65-70hz, with a gradual slope back down below about 20 hz where the slope falls sharply. (need to find my graph paper, just to see the pretty picture).
Interesting thing happens there in the teens with the cap off. The damn thing falls off in the same place, but is doing pretty well in the 'bottom of the well' so to speak.
Back on post #193, I said "18hz@130db may not be obtainable on a budget, but I 'might' be happy with 18hz @105db."   Well, the proofs "in the puddin'" as they say. John, thanks to you, I've got 20hz@105db. May play around with increments in 1hz from 15 to 20hz to see if we're there, but that's pretty damn close if nothing else.

BTW,  2 year old daughter can maintain 101db's when she's pissed, with an occasional peak to 108db. HZ is unknown, but painful.

Sound quality is perfect for movies (my goal) the torture tracks/chapters faired very well. The amp knob is now actually at about 1 o'clock (60%) during these tests. If memory serves, I believe I posted earlier that the knob was around 40%, and drivers were bottoming before the mods were performed.
Sound quality for music is ok, (granted the knob is at around 10 o'clock for music) but havn't sat down to actually LISTEN to some tunes without the family around. But what listening I've been able to do, does sound favorable.

John, would your Flinstones, or a OB in general "fit my bill"?

Bob
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #254 - 06/19/06 at 20:39:39
 
Bob has a real home theatre subwoofer!  Good job Bob.

I'd keep the cap off as response looks much flatter that way.
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« Last Edit: 06/19/06 at 20:41:27 by bassboy »  
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #255 - 06/19/06 at 22:06:19
 
[quote author=bassboy  link=1145573673/255#255 date=1150745979]Bob has a real home theatre subwoofer!  Good job Bob. [/quote]

Thanks BB, but the only credit I get is for the muscle part. Steve D. and John are the brains of the deal.

I'll save the cap for future 'playtime', just for grins. May leave it off for a month or so, after I'm 'used to it', then put it back on for a while.

John, thank you again.
Bob
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #256 - 06/20/06 at 11:53:30
 
Ok, I'll give this one shot....
Here's an 'attempt' at placing pics of my Niles surrounds.
I left the one inch screw in the cabinet for a size referance.





If that doesn't work, they're on my Webshots album.....

http://community.webshots.com/album/549522535hKJQbw

Bob

EDIT, hmmph.  Whadda know, it worked. (Thanks Jet  ;))

EDIT AGAIN, Now it doesn't work?  ??? WTF?

EDIT #3, Pics only display if I've got the pictures open on another 'Window'? Why is that?
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« Last Edit: 06/20/06 at 17:04:30 by Bob »  
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #257 - 06/20/06 at 18:21:21
 
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #258 - 06/20/06 at 22:53:40
 
Yea 60, I think you might be right. I believe you told me about them before and somehow, during the search, I got hold of a porn site that was tinypic...something. I though you were B.S.ing me at the time.

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #259 - 06/20/06 at 22:54:49
 
Bob,

Glad you sound happier.  If the sub wasn't in the corner for the measurements, you should give that a try.  That should give you some more boost.  For music you need to stuff the port for better sound, because an EBS type alignment will sound too loose with music.

BTW some simple mods should help those Niles.  I can't tell, are the cones of the woofer paper or plastic?  They need some deadening and bracing on that thin plastic cab, along with some stuffing in there.  Just for grins do a sound comparison with one open plus a piece of cardboard to extend the baffle and the other speaker stock.  

Do a similar measurements on one of the Niles.  Not max, just at a moderate set volume to see what extension they have on both ends and a general idea of response across the spectrum.  Any big peaks or nulls?

The Flintstones are the first pair of OBs I ever made in finished form and that was 2 years ago, when I was a noob.  What you want is my next similar set, although you might consider something similar and cheap in the meantime.  Use the guts of your Niles + 2 pairs of cheap 6x9's or 5x8's per side, as a simple test venture into OB's.
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« Last Edit: 06/20/06 at 23:38:59 by John in CR »  
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #260 - 06/20/06 at 23:09:42
 
Yes, sub was 1' from the right wall, and 6" from rear wall, with port facing back of seating.

Paper/Plastic; You know,...I'm not really sure. I'll have to look at them better. They're fairly shiny, like plastic, but couldn't promise that. I'll check.
They have a nice thick/dense white batting in there. Actually some pretty impressive stuffing. Hate the plastic though. Roll Eyes

Sounds like a weekend type project with the testing. Probably a better idea to check the same speaker (sealed then apart) instead of two different one's I'd imagine?

Liken' that OB thing. (read the WHOLE DarkStar thread, all 87 pages to date. Lots of stuff 'over my head')
I suppose a guy could just grab some mdf and cut 3 pieces, poke some holes, and see how it sounds. And some bracing of course.

Bob
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60ndown
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Re: hz numbers on a 15" 2 driver
Reply #261 - 06/20/06 at 23:45:41
 
[quote author=Bob in St. Louis  link=1145573673/255#259 date=1150840420] I got hold of a porn site

Bob [/quote]
and you wern't happy? Wink
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #262 - 06/20/06 at 23:53:47
 
[quote author=Bob in St. Louis  link=1145573673/255#261 date=1150841382]Sounds like a weekend type project with the testing. Probably a better idea to check the same speaker (sealed then apart) instead of two different one's I'd imagine? [/quote]

No, it's a 5min project.  No, not just one and stuff the woofer port and turn the XO cutoff up much higher to help fill in the bass.  Tape a piece of cardboard to each side of the opened up speaker to add some baffle to it.  Then play some music and pan left and right to hear the difference between OB and boxed, keeping in mind that the bass mayl be severely lacking on the OB.  With both playing though, the other one will fill in most of the missing bass, but you'll hear much more open and natural sound on the open speaker side.  It's not subtle and you'll wonder why they ever started closing up speakers (bass more cheaply and higher power handling are the reasons.  You want instant switching and direct comparison, because out audio memory is very short and only direct comparisons are worth much.

Quote:
Liken' that OB thing. (read the WHOLE DarkStar thread, all 87 pages to date. Lots of stuff 'over my head')
I suppose a guy could just grab some mdf and cut 3 pieces, poke some holes, and see how it sounds. And some bracing of course.
Bob


Cardboard and duct tape.  If you want to spend a few $, get a couple of pieces of the posterboard with the foam core that architects use for models.  Then with a serrated knife and tape you can try a few test speakers in minutes.  Don't worry about bracing on test cabs.  That's for a slight refinement at the end.  You just need them to stand up.

Does your center channel have dual woofers?  Once you go OB, you won't want the center anyway, so the drivers may be useful.  Open it up too for pics.
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« Last Edit: 06/21/06 at 00:00:01 by John in CR »  
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #263 - 06/21/06 at 15:06:08
 
Good advise John, I mentioned the weekend thing since I'd rather spend some 'quality' time listening to all of the various sources.
The surrounds are wall mounted. Would you recommend I remove them, maybe set them on a stool further away from the wall for the "OB test"? Or should I just experiment?

The center is MTM. I've peeked in the rear port once, found nice supply of stuffing. But will photo some 'exploritory surgery'. I've heard about people not using centers for HT, I understand the imaging and soundstage a guy can create with proper drivers and placement, BUT what about discrete channels? What do you do with dedicated center material?
Realizing an OB needs to be vertical with one end on the floor for bass, what about an OB center channel placed horizontal on legs? Center doesn't carry much bass anyway?

Would be cool if I could "bastardize" my speakers and make them all "baffleable".  hmmm, rear surrounds too?  ???

I know, I know, one step at a time, Bob

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #264 - 06/21/06 at 18:11:38
 
For seeing what OB is about, connect them in front in place of your mains and with the center channel turned off.  Use whatever is convenient and place them some distance from the front and side walls for the test listening.  Include music and some movie dialogue.  I love OB's for music and they're even better for HT, because dialogue is much more clear and natural.

Regarding the center channel info.  When you set your receiver to no center channel, then what usually goes to the center is sent to the mains.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #265 - 06/21/06 at 19:27:27
 
[quote author=John in CR  link=1145573673/255#265 date=1150909898] When you set your receiver to no center channel, then what usually goes to the center is sent to the mains. [/quote]

I've tried casually to find 2 channel output in the receiver menus, and have not found it. Never really tried though.
Will give it another shot.

60,  yea I did like it.  ;D But I didn't think they wanted pics of my crap on that site.

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #266 - 06/21/06 at 21:39:24
 
Probably where you set the size.
Large, Small, or None.
Mode would do the trick too, just 2 ch stereo.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #267 - 06/21/06 at 22:29:30
 
[quote author=John in CR  link=1145573673/255#267 date=1150922364]Mode would do the trick too, just 2 ch stereo. [/quote]

I think it's there....on the remote, however (since electronics ALWAYS know whats best for us  ::) ) the receiver is in some kind of "mode" that will not let me select any of the functions like 2,3, 5, 7, channel surround, in addition to all of the various Dolby doohickeys.  ::) It's locked on 7.1 surround (although the front/mains behind the screen have been unplugged for weeks)
....hmmm, may have to kick it.  ???

Bob
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« Last Edit: 06/21/06 at 22:30:49 by Bob »  
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #268 - 06/22/06 at 02:48:41
 
OB may be my final frontier, I've tried just about every box style that I know of so far.  I've got lots of high Q drivers but none that will go low enough to get down to 60 hz.  Unless I could be convinced otherwise, I've got 8 eight inch drivers with Qts higher than .6 and fs of 57.  Either OB or Frugal Horns, I don't have to decide for a few weeks yet.

Bob, this is what I would really like to see you try.  Use the full HWK size box (all three chambers, full volume of the enclosure) with one driver only.  Stuff the snot out of it with fibreglass.  It would have to be retuned a bit higher but I don't think it would be too much higher.  Then take your other driver and put it another HWK size box and put that in the other corner.

Same amount of power, same drivers but a whole lot louder.  What's a couple more sheets of wood?  I dare you.
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« Last Edit: 06/22/06 at 02:50:05 by bassboy »  
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #269 - 06/22/06 at 11:58:54
 
[quote author=bassboy  link=1145573673/255#269 date=1150940921]  I dare you. [/quote]

Is that a "double dog dare"?

I'm all about MORE for LESS. What's a couple sheets, ... $30?
I think John said that would net me about 6DB, give or take.

hmmm, might have to see what our resident Costa Rican friend has to say about this.

Bob
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #270 - 06/22/06 at 13:07:32
 
John, I saw your post on AC about the remote, but the thread is locked. ?

Try here...

http://www.remotecentral.com/

Bob

p.s. They've also got (buried in the site, somewhere) a nice section where people post the "cool" scenes of a movie, ie.. super low LFE, exceptional surround track, good examples of surround, ect.ect...
Kind of like the SVS site has a list of movies with super low LFE's.   Cheesy

Actually here's the specific forum for HTPC and general PC remotes.

http://www.remotecentral.com/cgi-bin/mboard/rc-pcremote/list.cgi

Bob
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« Last Edit: 06/22/06 at 13:09:06 by Bob »  
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #271 - 06/22/06 at 16:16:51
 
Bob,

I'm not Costa Rican, I bleed red white and blue.

Yes, +6db.  If you have them in the front corners, you should also get some mutual coupling in the lower frequencies, which offset the added distance.  Same tuning would require a shorter port due to the increase volume, so less port noise, but response would fall off a bit faster below tuning.  Try first by just taking the top driver off.  Then try it with your current port and just one driver in the top cap, which will tune you about 2hz lower.  That should get you pretty close to 100db at the listening position, maybe more, at those lowest frequencies with the second box.  The wave expansion from the front should sound better and blend easier, plus you should get some small gain due to placement at the end of your L shaped area instead of projecting from the corner into both sections of the L.

Nothing about the Xbox remote hack at RemoteCentral.  It's only $9 + a USB connector and a little solder, so I'll be the forum guinea pig.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #272 - 06/22/06 at 17:03:29
 
[quote author=John in CR  link=1145573673/270#272 date=1150989411]I'm not Costa Rican, I bleed red white and blue. [/quote]

 :)  Louisiana, right? Grandmother in Illinois?

Quote:
one driver in the top


Dual HWK's with 15"ers sticking out of the tops would look kicka$$ too! Like a gatlin cat launcher. I think it would pass the WAF.  ???

Quote:
Nothing about the Xbox remote hack at RemoteCentral.  It's only $9 + a USB connector and a little solder, so I'll be the forum guinea pig.


Oh, I didn't know it was a hack, thought it was a store bought thing.
Did you try the XBox forums, they have 10,000,000 - 15 year old kids there, surely one of them knows.

#1 I didn't know you were a gamer.  ;D (can't blame this one on the kids, John)
#2 What's it's purpose?
#3 I've got the wireless XBox360, will it work?
#4 Do I need it, probably so.  :-/

Ok, all you closet gamers, come out now.  ;)

Bob
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« Last Edit: 06/22/06 at 17:06:05 by Bob »  
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #273 - 06/22/06 at 17:17:15
 
Looks like you have a big advantage being in the US.  I paid $60 for 2 sheets of mdf and I thought that was pretty good.  I paid $150 for my 15" Quatro (lists $15 cheaper than your Series II's) and I thought that was reasonable too.

It appears Canadians are paying roughly 2x the cost for the same materials.  With this in mind, I think you owe it to yourself to make 3 more and get 12 db more output.  So there.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #274 - 06/22/06 at 17:35:47
 
Yea, welll.... um, ... I'd need another amp,.. and um... the space factor,... and well, um...Then the cost of drivers,.. and ummmm.
Dude, your psycho.  ;D In a good way.

Is that a triple dog dare?

So, now HOW many of those TL's you makin'?   Kiss

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #275 - 06/22/06 at 17:48:04
 
No Bob, I'm no gamer, although I did play Resident Evil 2 for the PS1 until I got Tofu (no memory card help).  The remote is just to control my PC (movies and music) instead of using my cordless keyboard as a remote control.  It's just a simple cheap conversion.

Regarding your sub, you'd don't need another amp.  Your current one is powering both, so it's the same thing, just 2 different boxes.  Same power needed, etc.
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« Last Edit: 06/22/06 at 17:49:55 by John in CR »  
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #276 - 06/22/06 at 18:12:51
 
[quote author=John in CR  link=1145573673/270#276 date=1150994884]Regarding your sub, you'd don't need another amp.  Your current one is powering both, so it's the same thing, just 2 different boxes.  Same power needed, etc. [/quote]


Yea, I knew that for the dual sub arrangment my existing amp would work, it's when bassboy got radical on me and wanted a "Housewrecker array" that I would need more than one amp.

Sorry bassboy, I think I'll have to pass on 4 Housewreckers.  :)
Cool idea though. Say,... how many HWK'ers do you think 60 could stick in his minivan?

John, I found this...

http://www.llamma.com/xbox/Mods/xbox_controller_to_pc_usb.htm

Bob
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« Last Edit: 06/22/06 at 18:20:03 by Bob »  
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #277 - 06/22/06 at 20:20:27
 
I'm just making one prototype to start, but if it works out well you can bet there will be at least one more in the other corner as time and money permit.

Depending on how serious you are about really low bass, it might be worth considering tl's.  My Quatro models about 6 db louder at the same tuning in a tl vs. ported enclosure.  The Series II doesn't model nearly as well in tl (down about 5 db compared to my driver), that's why I didn't buy one of those.

By the way, my box is under 16 cubic feet, outside dimensions, and takes up just over 2 square feet of floor space, how big is yours?

Full report in about T minus two weeks or so, lots of graphs and comparisons between different boxes and my Quatro 15.  There's even a comparison between Quatro and Series II in a tl.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #278 - 06/22/06 at 21:06:16
 
[quote author=bassboy  link=1145573673/270#278 date=1151004027]how big is yours? [/quote]

HMM, kind of a personal question, but if you must ask,.. well, mines exactly twice as big as yours.  :D

Ok, sorry, cheap shot. Fortunately I'm one of the lucky one's, I've got this 'extra' space behind the seating area, so subwoofer size isn't a concern. (and no, a couple Imperial SO's arn't in my future.)

Bob
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #279 - 06/26/06 at 21:34:16
 
Well, I started my journey down the OB road this weekend despite the fact my receiver 'shot craps'. I felt like I was installing new tires on a totaled car.  ::) Building speakers for a receiver that's broke.

Made some nice progress. I didn't have cardboard large enough, But I did have some leftover counter top (formica veneered particle board.)

Since I'm using "real material" as opposed to a temporary setup, I figured I'd do it right with symmetry, neatness, ect..ect..
I got the 2 front baffles made, routered resseses for the drivers. Drivers are complements from 2 donor Niles OS-10 surrounds that were originally part of my system.

The wind has been let out of sails with no audio in my house, so I'm like a little kid who's favorite toy has been taken away.
Not much enthusiasm.

Bob
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #280 - 06/26/06 at 23:17:31
 
Bob, got any regular 2 channel amps lying around?  Maybe steal one from the shop or the kids?

It might be time for some 2.1 channel OB for a completely different experience.  If you're going to get into OB, you might as well get completely immersed with only OB speakers (and sub of course).  Any other box types playing the same frequency range are going to swamp the OB's and you won't hear why they are special.

Life, lemons, lemonade, know what I mean?
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #281 - 06/27/06 at 03:02:52
 
Whoa Nelly!!!

Bob,

Please don't go hacking your speakers up.  We have no idea what those drivers are and they may not be suitable for OB.  I didn't even want you to take them off of the existing baffle, just tape some small additions on to what was already there.  You could have used some wood scraps or whatever.  Then leave everything connected, original box behind the baffle, and give it a listen, a 5 or 10 miinute process to get an idea of what OB sounds like.

I think it's time for me to stop throwing out ideas and let you explore away.  Feel free to ask questions any time.  The reason I  jumped in to begin with was that I hated to see you scrap a perfectly good cab, when I knew you could make some minor changes and achieve something closer to what you were looking for.  If my new sub works out, I'll run the numbers with your drivers and see if something similar makes any sense for you.
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #282 - 06/27/06 at 03:30:13
 
I'll admit that I know very little about OB but I do know that high Q drivers work best.  High Q = small magnet and lightweight material = drivers that can be very cheap.  I would assume old factory car speakers and old cheap home drivers would work great.  That equals free of charge.  So now that you have a frame I would go ahead and use it with a wide assortment of different drivers to see what's possible.  Small surround speaker drivers are probably not very suitable to OB but you should be able to get your hands on some good ones.

Other than the excellent resources here, there is a lot of info on other forums.  A good place to start would be diyaudio.com.

I haven't been interested enough to study any of it yet but I would think that you could make something that sounds and looks very good for very little and maybe even no money.  It might be hard to go as low as your sub crossover point for free though.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #283 - 06/27/06 at 12:04:00
 
John, No speakers were harmed during the making of the baffle.
The Niles screws were turned to the left, No damage done. Empty plastic enclosures complete with stuffing and screws are safely tucked away from the sawdust. If it all goes to hell, They can be reassembled. No harm done.

Please DON'T EVER STOP throwing ideas my way. Never, Never, Never.

When I build something, I don't take the time to make written plans. Because I'd probably change something anyway which would make the plans null and void. That goes for outdoor decks, indoor speakers, or entire finished basements. No plans. Ideas are generated and stored in the noggin.
So when I set out to try OB, I did a quick inventory of my building materials and found that the Formica was some pretty cool lookin' stuff (the counter top is leftover from the bar in my pics.) Thought it would be cool if OB's matched the bar.
Yea, I got carried away, took your idea to an extreme.
My ideas sometimes get extravagant, but an audio noob with radical ideas can be a dangerous thing. John, I like your ideas, keep 'em comin'!  ;D I'd rather build your ideas instead of mine. Granted, 'play time' in the workshop is a good learning experience for me, BUT, I'd rather build something with a more proven track record than what my brain can come up with.

By the way John, the drivers cones are plastic.
The tweet's domes appear to be a synthetic fabric type material, VERY soft material, the dome deflects with very little pressure from a finger tip. They've also got one heckuva large magnet for a tweeter (IMHO).

Early Saturday morning I stopped by the local pawn shop to check for orphaned drivers. All they had were large car subs, and guitar amps.
A couple local flea markets (huge one's) may be a good place to explore. Havn't been in years.
Unfortunately being a noob, I wouldn't have a clue what I'm looking at a far as what is acceptable for what type of enclosure (unless of course is says Visaton B200  ;D). And I'm sure the drivers sitting on a table at a flea market arn't going to have T/S numbers.

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #284 - 06/27/06 at 15:31:44
 
Bob,

Yes, the formica to match the bar would have been nice to use, but now you've used it on test baffles.

In general, you're looking for smaller magnets.  That is usually an indicator of higher Qts.  Ideas for cheap-  The 8" Pioneer full ranger from parts express for $25.  Check out car audio installation shops for the factory drivers they remove from the rear deck of cars.  Most of the whizzer coned 6.5" in the back dash are used in a free air alignment (IB), so their parameters are perfectly suited for OB use, and they typically sound surprisingly good especially with a tweeter added to the top end.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #285 - 06/27/06 at 16:31:59
 
[quote author=John in CR  link=1145573673/285#285 date=1151418704] but now you've used it on test baffles. [/quote]

Dammit.  ::)  I screwed that up.

Quote:
 Check out car audio installation shops for the factory drivers they remove from the rear deck of cars.


hmmmm, VERY GOOD IDEA .  OHHHH, Man, I'm exited now! That's a really good idea John.

Bob
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bassboy
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Re: hz numbers on a 15" 2 driver
Reply #286 - 06/27/06 at 17:41:27
 
I have an assortment of old Delco 6x9's and 5.25's from old cars.  I just assumed everyone had a closet full of junk...

This old, cheap stuff that is not so good for other box styles seems to be a great fit for OB.

There is even a local surplus store that sells the OEM Delco stuff.  The 5.25" sells brand new for about $4.

You are going to want some big drivers if you want to get low with OB though.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #287 - 06/27/06 at 19:18:25
 
bb, (soon to be bm) no closets full of junk/goodies. Havn't been into the hobby long enough to collect trophies.

Is 'big' and 'OE' possible?

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #288 - 06/27/06 at 20:42:36
 
I'm currently planning an OB bass augmenter manifold with B200's as the main driver.  They'll end up being quite compact floor standers with the woofer section 8-9" wide and 25" tall, which will contain 8 6"x9"s in each speaker.  They will be the equivalent of a pair of 15" woofer, but in a compact depth and drastically lower price.   Something very similar to my Flintstone cabs, but slightly taller.
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Bob in St. Louis
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Re: hz numbers on a 15" 2 driver
Reply #289 - 06/27/06 at 21:35:34
 
Hi John, I'm trying to picture the setup.
Like the Flinstones, is there a hole/slot in front baffle, surrounded inside the "enclosure" by another box with all drivers on the box, not the baffle.

Sounds interesting. Reminds me of some of those 'extreme' IB towers with a dozen 15"er, all radiating through a small hole.

Do I have the visual picture?   ???

Bob
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #290 - 06/27/06 at 23:53:11
 
Exactly, you just can't see the drivers through the front pathways because I put a piece of expanded metal over the opening from the back and those driver frames and entire chamber are painted black.  The work behind that is invisible but I was very worried about vibration noise from the grill and went to significant lengths to prevent it.  The new one will move a lot more air and will require a larger grill approach.  I'll also have to equally air mass load the back side too.

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« Last Edit: 06/27/06 at 23:54:58 by John in CR »  
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DirtDawg
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Re: hz numbers on a 15" 2 driver
Reply #291 - 06/28/06 at 03:16:47
 
Those look nice, John.
Are they going on stands or do you plan to angle them upward slightly.
The idea is similar to what I was trying figure out. I want to incorporate a "W" baffle into the main, with the 2 - 15s running push-pull. I like the use of smaller drivers in multiples, but I am a little spoiled with the low Fs (22Hz) the JBLs have.

I was using a MTM arrangement (2 - 15s + B200) for about a month and that really sounds great, but I tried to flip one of the drivers around and the difference is amazing. They remain that way, for now, but I'm getting tired of looking at (and bumping into) a 20 lb magnet structure. Roll Eyes
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John in CR
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Re: hz numbers on a 15" 2 driver
Reply #292 - 06/28/06 at 04:21:40
 
Thanks Dawg,

Those are about 2 years old and were one of my initial forays into OB.  I didn't plan for enough surface area on the augmenters and they sound really good, but only up to moderate levels.  The reason I want to try the 6x9's is that I can pack them into a more compact depth.  That way any depth in excess of 10" is 2 for one value and makes it a hybrid U-baffle.  That way I can keep it really compact, plus less pathway depth means I can cross as a higher frequency making main driver options more flexible.  My goal is to see how compact I can go with a high performance without cheating and boxing up the bass.  Whether I ever go to market with it is irrelevant to me.  I'm just having fun trying to do what no one else has, create a domestic size OB with real bass that can be driven by a single amp.
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