Wouldn't it also depend upon the sensitivity of the speakers and also on the source?
The receiver doesn't "know" how loud a 0db setting is in your room on your speakers at a certain distance. It can be a useful relative reference point.
My experience is that a setting of ~-10db on my modest Denon 1804 is quite loud on DD sources (DVD's) and is uncomfortably loud on analog sources (my old CD player, DirecTV box, etc.). I'm sure the average energy far exceeds 85db. I've never approached a 0db setting, even while drunk.
Getting a Rat Shack spl meter and a setup disk like Avia or Digital Video Essentials is a good way to go. It helped me a lot.
