what does polyfil do

I was wondering why do people put polyfil in there sub boxes, does it fool the subs into thinking the enclosure is bigger when u have a small amount of air volume.?  thanks

FROM WHAT I HAVE LEARNED FROM THIS Forum 12Volt.com The sound wave coming off the back of your subwoofer reacts with the air contained in the box. Poly-Fill stuffing slows down sound waves inside the box, making the subwoofer perform as if the box were bigger.

Polyfil, when used correctly can fool a woofer into thinking its in an enclosure anywhere between 0-20 percent larger than it really is in. Why would you want to do this? Well, when a woofer is in a bigger box, it can produce the lower bass frequencies alot better. Now, let's say, you dont have those extra 2 inches clearance in the trunk? what to do? STUFF IT!. 1990 Honda Civic HB:

Clarion DXZ545MP H.U.

2- 6.5" Power Acoustik interiors

Diamond Audio 600.1 amp

Diamond Audio 15" M6MKII

Pyramid PB881X 4 CH. Amp