does polyfill work?!?

[ls-r]

i have two mtx thunder 6000 in an undersized sealed box (looks like a box for two eights, good thing tho is i still have room in my trunk)..and a rockford fosgate 500 watt amp powering both...BOX IS EVERYTHING! i have some friends with some lower line products than me but with a bigger and better box and it hits better and bassier than mine. My question is can i just stuff polyfill/cotton in the back of the speakers inside the box to compensate for sound? I heard it makes the box appear as if it were bigger..and it slows down the sound waves..how much should i stuff? till its packed? or loose? thanks yall

[Sniper]

it does work to an extent, but it's not going to do as much as a correct sized box would...genereal rule of thumb is 1/2 lb fill for every cubic foot of volume.....don't pack it in or it may cause the waves to simply bounce off, effectively decreasing the size of the box...leave it loose, and if you can, keep it off of the sub to allow better cooling....