I'm running a PB2-isd with my M60s, QS8s & Vp150 in by 14x24x7.5 basement. That puppy is a monster and has more than enough power that you don't have to worry about clipping the sub, the gain is only at 1/4.

M60s, VP150, QS8s(3), SVS PB12-isd, Denon 3805, Emotiva UPA-7