To bi-wire the M60s, you should connect the two sets of cables to the left and right speaker outputs for Speaker A.
Don't use the outputs from Speaker B to run the right-channel speakers. I believe you may have introduced an out-of-phase condition, which would mess up your surround sound in a major way (no permanent damage, by the way.)
That said, there is no acoustical benefit to bi-wiring. It just lowers the resistance between the amp and the speakers (it can't hurt), but so long as you are using quality cables of sufficient gauge, there is no sonic benefit to bi-wiring. It just creates wiring problems like yours with consumers and lets cable companies sell more cable. So put back the jumpers on the M60's and connect them normally with one set of cables to each speaker. Your surround sound will be fine, and there will be NO difference in sound quality. Trust me on this one. No carefully controlled listening tests on bi-wiring have ever demonstrated that there is any sonic benefit to be realized.
I'll deal with bi-amping another day. . .
Regards,
Alan Lofft
Axiom Resident Expert
