I have a Denon 2802 that drove M60s, et al, to extremely loud levels on its own (I have since added an outboard 2 channel amp - a sensible upgrade, IMO, if you have some spare coin).
For the original poster: the speakers are not to blame, and it may not even be the receiver. Everytime I had a problem with something, it seemed to come down to error on my part in set-up. I'm guessing that is the case here, as well. OTOH, my digital cable box does require more turns on the volume knob to achieve the same spl levels as other sources, but not to the extent you are experiencing.
AH HA! You're not running the audio signal to the TV first and then out to your receiver are you? If so, the TV's volume level will determine how much signal goes to the receiver. Eureka!
