Welcome, Guest. Please Login or Register
Decware Audio Forums
10/21/14 at 13:05:52


Pages: 1 ... 11 12 13 14 15 ... 20
Send Topic Print
hz numbers on a 15" 2 driver (Read 40876 times)
bassboy
Ex Member



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.
Back to top
 
 
  IP Logged
John in CR
Ex Member



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.
Back to top
 
 
  IP Logged
Bob in St. Louis
Ex Member



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
Back to top
 
 
  IP Logged
Bob in St. Louis
Ex Member



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)
Back to top
 
« Last Edit: 06/05/06 at 15:56:12 by Bob »  
  IP Logged
Bob in St. Louis
Ex Member



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
Back to top
 
 
  IP Logged
bassboy
Ex Member



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.
Back to top
 
 
  IP Logged
DirtDawg
Ex Member



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.
Back to top
 
« Last Edit: 06/05/06 at 19:10:59 by DirtDawg »  
  IP Logged
John in CR
Ex Member



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.
Back to top
 
 
  IP Logged
Bob in St. Louis
Ex Member



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
Back to top
 
 
  IP Logged
60ndown
Ex Member



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.
Back to top
 
 
  IP Logged
bassboy
Ex Member



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.
Back to top
 
 
  IP Logged
John in CR
Ex Member



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.
Back to top
 
 
  IP Logged
Bob in St. Louis
Ex Member



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
Back to top
 
 
  IP Logged
Gex
Ex Member



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
Back to top
 
 
  IP Logged
Bob in St. Louis
Ex Member



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
Back to top
 
 
  IP Logged
Pages: 1 ... 11 12 13 14 15 ... 20
Send Topic Print