Makes my boxes sound better. Why though I don't know.
did for mine. but expairment, find out foryourself. Wal-mart has a 2lb bag for $7. i used a 1lb per cuft. others will tell you it will make it feel like its in a bigger box. seince I dont have a 2nd box i wouldnt know.
it slows down the air waves been sent to the back of the box, making them take longer. thus, it seems as though the box is bigger because it takes the waves longer to get to the back of the box and back.
yes but adding polyfill isnt always a good thing because pollyfill decreases the amont of low hz output but increases the amont of hi hz output for a person that likes deep low basslines and extended bass notes this isnt a good thing but the good thing is it only alters the levle of output by 1 or 2 dbs wich in most cases u wont even kno the diffrence so in car stereos polyfill really doesnt do much it is meant to be used in home stereos that are specificlly tuned hi this is because they are running off of 8 ohms not 4, 2 or 1 ohms like car stereos do in that kind of aplication the sound diffrence with polyfill and without would be alot more noticable