Can't say for sure, according to Axiom and a few others, most Denon's will drive 4 ohm speakers just fine. Not sure if that is referring to every model Denon puts out, or the recent models or higher end models.
I will tell you this, I have about a 30ft x 30ft x 9ft ceilings room and my M60's, combined with the rest of my Axiom speakers will blow you out of the room if you ask them to
I'm actually more interested in investing in the EP500 or EP600 sub at some point. My EP350 does a great job when combined with the 60's bass performance, however, for the real low freq. effects, I think a second sub will help blend better.
Seriously, you do need to give this some thought. I would say if you were the type that likes it crazy loud for the whole block to enjoy, by all means get the 80's
The other day I had my 60's cranking up some Winger and Dokken, my neighbor later asked me if I got a new stereo system, since he could hear the music. It is the dead of Winter here in Iowa, and I have all the windows closed. Besides I live on 3 acres, so it is not like he was right next door. So the M60's, in my opinion will probably be more than you are hoping for.
They are awesome speakers, as are the m80's, such a tough decision...
