I believe it is only 14 day return policy for FS.
You are correct you should have enough power for the M60s. As it has been suggested on the other Subwoofer thread I think trying to set up the sub calibrated to the same SPL as the M60s at the M60s lowest drop out out point might help, possibly in that 30-50hz range, just to fill in that extreme low end that the M60 can't produce.
I just tried my old D-Box(they make Butt kicker furniture now) sub that goes down into the 25hz range calibrated at 80hz crossover point and it sounded pathetic. I have to drop its calibration point to the M80s lowest output to get it to sound even, still nowhere near what I heard with the EP400 but better.
