Adrien, the M60s could certainly be set on the 1400 to reproduce the full range, including bass, when you play in stereo. The general procedure should be to set YPAO to skip setting the speaker sizes and crossover and instead manually set all speakers "small" and the crossover at 80Hz. YPAO should then be allowed to set equalization, levels and distances. Then, if on some occasions you'd want the M60s instead of the sub to handle the bass, you could temporarily manually reset the M60s to large, and/or set the bass to front rather than subwoofer. This of course would then bypass the 80Hz crossover. In my view however, there's no good reason to do this. A good sub, properly located and calibrated, will give better overall results in the lowest bass than even speakers such as the M60s which have good bass. Stay with speakers small and the 80Hz crossover for both HT and all types of music.
As to whether M22s with the good sub would be just as good as the M60s, opinions have varied. Some have reported that the sound above the low bass was essentially identical; others have said that the M60s sounded "fuller" even above the low bass. The M60s would be able to play somewhat louder in very large rooms.
