Originally Posted by jkkyler

I use audyssey to calibrate so why wouldn't it know since it measures spl and my amp adjusts from -80db to +15. Good point though about 10db being closer to the sound and 3db being half/double the power - I totally turfed that.

For anyone interested here is some god info:
http://www.sengpielaudio.com/calculator-levelchange.htm

for onkyo at least:
from a Onkyo manual: "A home theater system automatically calibrated by Audyssey MultEQ® XT32 will play at reference level when the master volume control is set to the 0 dB position. "
When switching volume display from "Absolute" to "Relative (THX)": "The absolute value 82 is equivalent to the relative value 0 dB."

Seems 0db is not maximum power but 85dB reference level anything above that is greater than reference level.
I have my amp limited to 0db even though it goes to +15 but I rarely get above -15db