my friend has hekka cotton in his sub box. Can anyone tell me what this is for?

 

Box stuffing can improve bass by minimizing unwanted box resonances.

 

basically in easier terms it makes the box think its bigger

 

From what I have seen most times u want to pack it with cotton is if its a crappy store bought box and or a poorly built box. Reason being that a poorly built box doesnt have the right dimension or wasn't sealed right, thus lets air pass through the seams. Store bought boxs just suck so u gotta fix them after ya buy them.

 

true... but some boxes cancel out bass due to the box being exactly square and matching the resonance length for the low frequencies generated by a specific sub.

 

not all store bought boxes suck. mobile spec has a whole line of them coming out that i have installed in many customer cars and they are great. i can stick a 8500 mtx in one with the proper air space and run 1200w to it no problem. probox also makes literally indestructable boxes, they are coated with urethane instead of carpet, it almost looks like line x. i see no point in stuffing a box with cotten, if you dont have enough air space go with a smaller sub and run more power to it.

 

^^^Do you own a shop??

 

Stratguitarist puts it the simplest - cotton is also especially good in situations where it's not possible to have a very large box (i.e. a truck) or in sealed enclosures...

As for store-bought boxes, I believe QLogic makes a fairly good box, although not matched to an individual sub.

 

Sealed boxes are pretty forgiving if you go slightly over or under so it doesn thave to be dead on. Ported boxes on the other hand are much more sensitive.