hey i'm building a custom box... for 2 10' JL Audio subwoofers, i'm probably gettin W3's.... but the way i got this box designed i will only have like 1.16 cubic feet but i wanna put a divider in leavin me with like .508 feet per sub.... sub recommendation is .975 or something... will i be able to do it still or am i askin for trouble by cheatin the space... ??? not sure what to do ? ?

 

Did JL give a range of airspace? If the bottom end is .9 and you do .5, it wont sound good at all, esp if its ported.

 

You need a bigger box, or one less sub.

 

some ppl believe that filling the box with something like fiberglass insolation will trick the sub into thinking its larger box.
also some ppl mount them in upsidedown to get alittle more internal volume.

 

actually, when you fill the box with roughly 50% of polyfill(safer than fiberglass to handle) it doesn't trick the woofer into thinking its a bigger box, it makes the airflow behave like its a bigger box. By adding 50% of fill to the box, it actually slows the air down, making the woofer behave in a manner similar to a larger box, but anytime you have a woofer in a box, you want some kind of fill as it buffers any muddiness and cleans up the bass, makes the woofer more responsive, and you have less resonant waves bouncing around inside the box, so the woofers surround takes alot less of a beating while pounding away.

 

There. now you're right.

 

yes thats what i ment. But ive tryed both ways in my box with and w/o and i liked w/o better. No hurt in trying it.

 

yeah sometimes the fill doesn't make much of a difference.

 

Good quality fill can fool the sub into thinking it's in a 10-15% larger box... still nowhere near enough to make a W3 sound good in .5 cubic feet. Hell, they don't even sound good in the 1 cubic foot they call for... they need a little more space than that.

 

What kind do you recomend or what kinds are good?? Im still trying to think what i used.

 

I like polyfill, its for sale at walmart, and is pretty cheap, its as good as pretty much everything else available. Its safer to handle than fiberglass, and is like 2.50 for a 20 0z. bag. A friend of myne told me also that some car stereo mag said it was great for boxes too, even though I used it before I knew about it being so great.

 

the other option is to build an Isobarik subwoofer box, but that involves another 2 subs & isn't quite as cost effective

 

There are brands designed specifically for this purpose. Parts Express sells one called "acousta-stuff". This stuff is a little different than regular poly fill. I believe it's more dense. You only use about 1/2lb per cubic foot of airspace, but it's supposed to be a bit more effective.

I've never used it personally, however, so I'm going by what I've heard on some of the DIY audio forums.

 

Yeah I saw that stuff from parts express, but I was too lazy to spend the money on it, I'm sure it works as well if not better.