Jimmie - thanks for the additional info. If you're running the amp to clipping and shut down, then you're probably a good candidate for separates. When I said "elsewhere," I was thinking specifically of adding a second EP500 or a pair of larger subs (EP800s). Their increased extension and volume capabilities might make a nice difference as well given the volumes you're listening at.
IMHO, the sub advice is more applicable if you listen to more movies than music as you'll notice the increased extension a lot more in movies. However, in a room your size, even for music at moderate volumes, having a second sub would likely smooth response throughout the room considerably.
On room size, I was just asking for an estimate of your ceiling height. If they're cathedral ceilings, a totally back of the napkin estimate would be to take the max height of the ceiling and divide by two (or take times 2/3 depending on the slope of the ceiling, etc.) as an average height for the room. This is far from perfect, but it gives a ballpark. i.e. if the peak of the ceiling is 15', assume a 7.5-10' average height in the room. If this was the case, you'd have 9,000-12,000 cubic feet to fill (based on your square footage estimates). In a room of this gigantic size, it seems like a second sub (or 2 bigger subs) would be a very good addition as well.
Also, back to your original question, from everything I've stated here you'd have no problem running the M80s at those power levels as they're built to withstand far more.
It goes without saying that I wish I had your problems.
Jason
