Hi,

Follow Mark's advice on switching the speaker channels to make sure it's not your electronics that are at fault. The drivers are easy to change out if indeed you've damaged the drivers. You mentioned your preamp, but what amplifier are you using to drive the M60s, and what is the rated power output per channel into 8 ohms? Is it solid-state?

Regards,
Alan

Alan Lofft,
Axiom Resident Expert (Retired)