I Run a 2000watt Audiobahn amp on two 15" Audibahn 1300watt aluminum subs, and I am getting some distortion around 145.5db
my old subs were 1000watt audiobahn aluminum subs and they ran 149db fine, so I went to the stereo shop and they told me the 1300watt subs had too much space to move inside my box and told me to isulate it to take up some space. Does this sound logical? if so what should I use to fill up some space?

 

Yeah, the insulation can make a difference. What works good is to get some insulation from the hardware store. The stuff that rolls out, not the shredded stuff. What I used to use is foam like the stuff they make chair cushions out of. You can run a test by putting some pillows in there too. If you have a couple of those eggshell pillows, they would work best. Anything that isn't too dense. The main thing that I tried to accomplish with the foam is it deadened the "reverb" from the wood the box was made out of, but it will take up some air space also. It's worth a try. Good luck

edit: btw, that's a nice setup you got there. Looks like enough to make the bill of your hat vibrate.

 

GREAT SETUP...yeh..i'd defintely get insulation.....cotton blend i believe....i dunno....or cut the cover of a pillow and use that stuff....it should work well....i would LOVE TO HAVE A SETUP similar to that..good job man

 

I'll try the foam trick, if it works well should I put adhesive or something on it to keep it from moving or will it be fine? And thanx for the compliments, I've been building this for db drags but my main competitor is a 94 Dodge Dakota with eight 10"s there aren't alot of trucks around here with 15" subs

 

If you add polyfil (insulation), the subs will think that they are in a larger enclosure. It sounds to me like the shop was telling you that you have too much airspace already. If that's the case, find out how much air the subs need, then add some blocks of wood of the appropriate size to the inside of your enclosure(to reduce airspace). You can glue them in or use screws. If you use screws, be sure to use short enough ones that won't make any airleaks in your box.

BTW, Nice looking setup!

 

^^^ I agree. I think the stereo shop was talking about insulation as in a sound deadener (dynamat, peel & seal, etc.).

 

Really nice set-up! How do you keep the glass in your truck ??


On a serious note: Do you have front to rear bracing in the box? This makes a larger difference when you run monster subs and power like you have.

I would also line the entire box internally with sound deadening material (RAAMmat, Dynamat, etc.)

I think Robdude30 is dead-on. Adding wood to reduce the internal volume of the box is a great idea. If I were you, I'd glue and screw the pieces into the box.

BTW, if you do use glue inside the box, be sure to pull the subs out until it has a chance to cure. Some glues give off gasses or fumes that can disolve the binding agents used to assemble the subs themselves.

 

You can buy pillow-sized bags of polyester fiber fill like that used in sleeping bags, at fabric stores. This is inexpensive, easy to use, not fiberglass, and dampens the box volume perfectly. Often used in home speaker construction, and in many of my auto setups.