They sound similar.

The M2s play best with subs whereas the M3s can play most music without, due to its lower reach. My M3s are corner located so can produce some decent bass.

My M2s/EP400s sound more impressive as a system than the M3s due to the subs contributing such a powerful low end. They can reach down to 17 Hz & are so 'musical'.

It is too bad that the 400 is not in the lineup anymore...

TAM