The best sealed volume for a sub that big is about 2 cubic feet, now you have alot of choices here. One, youe could go with a sealed box and your woffers would sound great. Two, you could go with a ported box and they would sound ok. And three, you could get a band-pass box which from what I hear makes any sub-woofer over 10 inches sound like sh*t. The one that I would go with would have to be the sealed box.
If your having trouble building it or anything with volume E-Mail me for more information.
Senor Wae
"In the beginning there was the WAE!"
Saab 9000 Turbo
Sony CDX-M630
Diamond Auido 3.5(2 Fronts)
Alpine Type-R 6.5 Component(2 Rears)
Alpine Type-R 12(3)
MTX Thunder 81000D(1000w x 1ch.)