when calibrating my subwoofer, should the volume gain on the sub be set to 1/2 or max? when i calibrate the sub with the rest of the system (the sub being at 1/2 gain) i have to leave the sub at +10 decibals so it reads 75 on my sound meter like the rest of my 5.1 system. does that sound right? +10decibals sounds kind of high being that the rest of the speakers are at +1,-1,0 etc. what do you guys think?