If installed correctly, the M60s are anything but muffled sounding. Your Pioneer should drive them well. If wired correctly (correct polarity, no shorts, bi-amp clips in place and tight) then I'm thinking it's a receiver issue as Randy is suggesting. You might want to reset the receiver to factory and try running the calibration again.

I had to replace a driver in one of my M60s; trust me, they're wired in tight.


Steve Axiom M60v2, VP100v2, SVS SB12-Plus Yamaha HTR-5990, Oppo DV-981HD Samsung LN-S4692D