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.