I have the classic Ascends, 340s across the front and HTM for surounds. My room is 14x12x8.5 with a big opening into the Kitchen off to the side. I used master & commander to set the input levels on my Denon 3805 to prevent the 1124p from clipping. My volume on the avr was around -8 or -10 I can't quite remember. Once I was all done though I couldn't watch the movie at that level. The volume level was so intense I couldn't focus on the TV screen. 46" It actually drove me out of the room. The loudest that I can crank the volume is about -17 or 18 on the AVR. -15 is quite intense but fun for demos.
My typical volume is -28 - -24. My point being is they fill the room with plenty of sound :raped:
If you decide to demo them, I'm sure you will enjoy them.