>>I am considering either another set of M2s or a set of M3s for the bedroom, but they would just about always be used at very low levels to go to sleep to. Is there as much of a difference when they are both played quietly?
I found the biggest difference at low volumes, maybe because the M3 response curve is shaped a bit like the Fletcher-Munson "loudness compensation" curves. M2s sound really good if you crank them up -- I guess the bass becomes loud enough to hear
Based on my limited experience so far I think the M3s are the obvious choice for a low-volume bedroom system. The only (minor) downside is that there is a bit more noticeable bass so more potential for disturbing someone but you're going to be playing pretty quietly anyways.
Note -- if matched with a good sub I would still prefer M2s to M3s. Just had to say that.
