At some point, you have to compare the M80 to M60 without subs, at FULL RANGE. All this 80hz cut-off business is nice, but fact is, if you want to compare two speakers you have to let them do it on their own. I expect you are actually handicapping the M80 as it should go lower, but I'm curious.

Panny 3000 PJ, 118" Carada, Denon 3300, PS3, Axiom QS8, PSB 5T, B&W sub, levitating speaker wire