Eirepaul, I have to agree with Nick250 assesment off your post. Disregard large room and undistorted sound for a second, since any speaker can have problems with these factors. Where you were wrong in your assement was the phrase,
I have speakers that need high power inputs. The mini monitors/CC370 are considered fairly efficient speakers, and require minimal power to achieve insane db levels. Take a look at
SPL calculator, and plug in some numbers and you'll get a decent idea the type of db levels your putting out. I know it doesn't take into account room volume but it gives you an idea.