Forgive me for a potentially stupid question, but I don't have a switch for A/B-ing speakers so when I was testing the M60s and M22s side-by-side, I had to continually swtich the wires (and I didn't have banana plugs to make it easy).

What would be the problem with hooking, say the left channel to one M60 and the right channel to an M22? Maybe also switching to a mono mode to make sure the same signal was going to both?