I agree with Mojo.
Haven't heard the 60 or the 660 but if the M2, M3, M22, and M5 are any indication you will be fine. These smaller speakers sound great and fill a much larger space than their size would indicate. One more consideration, if this is a home theater, is that a smaller speaker is easier to fit into a space than a taller one especially if you ever decide on getting a really big screen.

Last edited by rrlev; 02/06/21 07:36 PM. Reason: added last line