Without a sub, the M2s are just a bit too thin in the bass unless you are listening to exclusively jazz & small-group classical (solo instruments, quartets etc..). M3 or M22 both seem to have enough bass response to stand alone although M3 will probably be more satisfying if you have a lot of pop/rock music on the agenda.

M2s with a good sub really do sound good, and the only thing you give up is the ability to play loudly. M2s in your room would be perfect for "comfortable" listening but might not be able to fill the room with really loud music if that's what you want some times. Either M22 or M3 would be more than capable of filling the room -- never tried matching M3s with a sub but I imagine the M22 would be easier to match because the bass response is smoother.


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8