So when I got my box it had the fiber filling in it and over the years and three sets of subs later it got thrown away. now my system sounds good now really good but ive read that the fiber makes the subs think there is more air space and make them hit lower

anyways i have a sealed box with 2 RF p1's
a RF 3002 amp bridged
a mtx thunderform box with 2.5 cu feet

should I but some fiber filling back in it? if so how much? and where can I get some?

or is it just mumbo jumbo?

 

if the box has the right amount of airspace for the subs then no need it putting any in it.

 

If you like the sound I would stay away from the fiber fill, it can compress over time and lead to problems. Just another gimmick to sell prefab units...

 

Actually fiber fill is used in alot of sub applications. If you like the sound, then by all means you don't need it. However, adding fill to a box makes it less 'boomy', and can tighten the bass. Also, adding fill to a box can actually make the woofer think the box is bigger than it is.

Every time you replace a sub in a box, you should yank the polyfill and restuff it. It's just basic pillow stuffing you can get a Walmart. Don't pack it tight, just enough to fill the voids.

I use it in all my boxes.

 

ok so rockford recommends about 1.2 cu for each sub so my box is the right about the right size. the only thing that im wondering about is tightening the bass? what does that mean? Im not exactly new to car audio but im no db racer lol.

 

Think of the fill like dynamat for the inside of the box. It partially deadens the inside of the box, so only the speaker is involved in making sound. It also slows the air inside the box, so when the cone pushes the air in, you don't get a pressure wave rebounding off the inside surfaces causing extra reverb when the cone comes out. Since you don't have significant vibration in the box itself, you only get the notes passed to the speaker. Hence "tight bass response".

Oh, and just in case anyone is thinking of it, I've never seen anyone actually put dynamat inside a sub box. That would be crazy, but interesting.

Here is a site with a little more explanation of the 'volume cheating' you can do with the poly.
http://www.klausaudio.com/subwoofer-...woofer-box.php