Wow seriously, the XPA-2 kept shutting down? That's crazy as it is a dedicated 2 x 500 watt amp. I would have thought that would have been PLENTY of power to keep up with the M80's power thirst... at what volume was Mark running it on??? Lol...
Now see that is the prime reason I've been looking for an external amp. When I was pushing my Cerwin Vega's (I'm thinking they were 300 watt speakers, but I can't remember for certain) at very high levels, they would start to sound very strange after a period of time, almost as if someone were playing with the eq or something. I never had another set of speakers to hook up to the Denon so I'm not sure if it was a problem with the speakers, or if it was an issue with the 4802. At any rate I figured a good separate amp couldn't hurt, and would do a better job since all it has to do is worry about power, unlike the reciever which is busy with a whole host of other things at the same time as trying to push clean power into the speakers.
Thanks for the info on different ohms also. I was never really sure how that worked, now I understand it a little bit better. That will certainly help when I'm looking for an amp.
