My HT room is of similar size and I was able to get the EP500 to blend very nicely. If anything, it took a big sub to meet the challenge of a square room. My couch has a VERY noticeable amount of less bass than if I walk over to the rear corners and some other spots in the room. It can be uncomfortably loud in some areas compared to the seating area.
Of course, I have little to nothing to diffuse the standing waves and refections and such so it's worse than you may have it. Unfortunately, this is the last room to get dollars put to curtains, rugs and other sound enhancing decor because we are still trying to get our main living areas filled in our new home.
The EP500 is till my most favorite thing ever, after my Jeep and of course my wife. Who probably will never read this, but you can't be too careful...
