is there any sorta stuff I should put inside the sub box? I was lookin at a walkthrough of someones boot install and they "cap filled" it or somethin, looked like foam.

any ideas?

If the box is sealed properly and is the correct volume or even slightly larger than whats recommended for your subs then no need for any internal fillings.

Only normally required if the capacity of your enclosure is smaller than whats recommended. And even then you honestly dont need it you will gain a lil more spl from it by adding like a fabric like dakron or expander foam..but just depends whether you really need it...

I'd make your boxes...seal all the edges with a good silicon glue or along those lines....and if its the correct size enclosure...leave it....if it smalls just buy some dakron...its cheap and no dramas to fit...

As Big Kev said, not really much point. I've tried many boxes with and without and heard no difference. But since I have heaps of it laying around already I chuck it in anyway, it can't hurt if you already have the stuff (dacron).

wot about like this cotton wool stuff, i have heaps of it laying around does it really make that much diff ?

well thats sorta like the dacron stuff...I havent noticed it make much difference except with big woofers like 12" and bigger in too small an enclosure...but even then to the ear it wasnt that great a diff....pays just to make the appropriate sized enclosure for your woofer in the first place....if you dont like that it requires too big a an enclosure or is gonna rob u too much boot space then dont go that bigger woofer or put it in a smaller enclosure and expect to get less performance out of it and not get ya moneys worth...in the end if ya dont like that a sub will require so much space spend the money on a quality woofer thats the next size down...

I dont believe it has any impact on the percieved size of the enclosure but i have found it reduces wooden ringing especially in boxes that are not carpet covered.

I alwayss pop it inside sealed boxes and often line te walls of poted boxes to reduce any wood ringing sounds.

Should only be $10

I did some experiments on this subject a few years ago using a sealed box, 3 jl10w6's wired to 4ohms, a series resistor, an osilloscope and a signal generator.
The theory is that by stuffing a box full of dacron or similar it gives the affect of a larger box, this in turn will affect the resonance of the system. When a speaker reaches resonance the impedance of the speaker will spike so by changing the box volume the resonant frequency (fs) will aslo change, as the box gets larger the fs will get lower in hz.
With the resistor in series it is a simple case of using the cro to measure how much voltage is dropped across the resistor, when the fs is reached the voltage will be at its lowest as there is less current being drawn therefor less voltage, simple ohms law.
So in my test I started with no fill and measure the fs and then with the box half filled measured it again and then with it full measured again. Each time the with extra stuffing the fs should fall according to the so called theory but the exact opposite occured it actually went up.
Make of that what you will.......

yep thats the sound i was getting with my single 12" a really loud wood ringing sound.. it sucked so i made my new box and linedit with some packing type foam all over the indside of the walls corrected that s**t sound i was getting

cheers