Are any of you guys even looking at his question?
DO NOT use the IB3, they are not regular Sub-box subs they are IB(infinite Baffle) subs, AKA Home theater type subs, i would explain why, but i don't fill like typing that much.
Just get a SSD 15'' run 800-900 to it in a 3.5cuft@35hz box, and you will be happy.