Interesting post. I recently started setting up a HT system. Have the HDTV and got a great deal on the Onkyo sr800. Now I need the speaker system to finish it out. Yes, this receiver states it is capable of 4 ohm operation with a setting change, but I don't really know how that would affect its operation relative to sound quality, volume, etc. So to stay within the know area of the amp, I have been considering the M60s (8 ohm) over the M80s (4 ohms). Where has my thinking gone astray ??