not easily
not easily, and, why would you, it has tons of output.
Mind you, theres a sharp roll off.
If you added one, it would have to come out of another subwoofer pre out like the one for the 6 channel direct, but it would have the center in it as well, but you can cross it out. Then you would have to step it up to rca from 3 mm and then plug it in. seems like a waste of time.
try that.
sheep
