depending on what you are driving, I would go with a ported box. Ive heard these subs in a sealed and a ported and with out a doubt the ported is much better. Read the owners manual that came with the subs and see what Kicker suggests for the subs. If you have a van or an suv(any vehicle without a trunk) i would go bandpass. I had a Q-logic bandpass box in my van and it was awesome. But like I said, see what kicker suggests and go with that.