I keep hearing about putting polyfill in a box for speakers, subs, etc. What purpose is polyfill serving in this box? Do you always need to put it in a sub/speaker box? How do I know how much I am going to need to put in the box (is there some calculation or something)? Where can I buy it from? Can anything be substituted for polyfill? Thanks

Ryan

 

Most people put polyfill in sub boxes to "trick" the sub into thinking its in a larger enclosure than it is.
No, you do not need to add polyfill but often it makes a small sealed box sound deeper. Plus you can add and remove to your taste.
Poly can be bought at any fabric store or upholstry shop(it's pillow stuffing). I usually use 1lb per sq. foot.