Hi Nashvegas,
You really should regard the "0-dB" level on your AV receiver as a cautionary level beyond which you may risk clipping and or increased distortion. As JohnK has pointed out, it's a very rough approximation, but understand that as amplifiers approach their maximum output distortion increases.
The M22s when mated with a good subwoofer, will reproduce "quite loud" to "very loud" levels of 85 dB SPL to 95 dB, respectively, at your listening position in an average sized living room of 2200 cu. ft. about 8 to 10 feet away. However, don't expect them to cleanly reproduce the crazy-loud levels of the M80s or M60s in bigger rooms, great rooms with cathedral ceilings or similar spaces at greater listening distances. I'm speaking of 100-dB-plus levels, which the M80s or M60s will do in larger spaces fed with robust amplifier power.
As remarkable as they are, the M22s are nevertheless a "bookshelf speaker," with maximum output limitations and compression issues that all bookshelf speakers share.
Generally speaking in all things audio, the "0-dB" level has historically been the point beyond which distortion will significantly increase and may become audible. So avoid it.
