Forums - hz numbers on a 15" 2 driver

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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