Let's not forget that, in general, the smaller the speakers, the more power you need to attain a given level of listening volume. This is certainly true for the Axiom lines -- the smaller models are usually less sensitive/efficient. For example, to attain a given volume level at the same listening position, the M2s (92db/W/m in-room) actually need twice as much power as the M22s (95dB/W/m in-room) do.