I see you have never ran any real subs. Size does matter alot though, it dictates the roll off of you peak freq.'s. Box size and type also are dependent on your subs and beleive it or not your amp. Like said above do not cheap out on the box, a bad *** box can make a cheap *** sub/amp combo sound like a million bucks or make a high dollor sub/amp combo sound like a fleamarket speacial.

 

Build one yourself? Work out the airspace you need inside the box (one 12 nich sub usually needs one cubic foot, so 2 subs would need 2 cubic feet) I think the calculation is height X width =N and then N x Depth... Please dont quote me on this though, it was ages ago that I did my box.

 

I built my own box. I made it for a 12 inch sub. I think it cost me 15$. I got 3/4 mdf fromhome cheapo, but I was lucky to find pre cut pieces that were cheap cheap cheap. Then I got some sealant and screws, and carpet. Took maybe 40 mins to make it from start to finish.

 

http://www.bcae1.com/spboxnew2.htm
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Thats what I used when I was scrapped for space and needed a certin volume out of my box. You can get exact dimentions to fit your sub perfect. A lot better than spending money on a name brand box thats "close" to the right size.

thats the best way to go, make sure its mfd though. It's also a good idea to drill pilot holes for the screws and make them countersunk. Holds a lot better that way. I also used liquid nails on every seam, then after a day went back through on the inside and calked the cracks. Carpet it and you're done. You'll gain experience and get a good quality box for cheap.