I've got an Infinity BU-120 150W sub with a blown amp module that seems to be no longer manufactured. The rest of the sub is in excellent condition. I know that if I buy a new amp from PE, I'll have the problem of finding one to fit perfectly or covering up the hole left by the old one. If I opt for using it externally, can't I just leave the old one there and just have the two speaker wires coming out of a small sealed (silicone?) hole?