I have experience personally with Rockford Fosgate and Kicker. The Kickers are usually louder but less accurate. The Fosgates are much more accurate. P3's are good and they hit nice to if you have a decent amp. For the price I would say they are well worth the money.
That box must have been ported. But the quality of Rockford Fosgate as far as subs go, is not very good. I recommend getting kickers instead of Rockford Fosgate. Or what you can do is ask whoever owned those subs how they hooked everything up. Good Luck
