Okay, I know that this topic has been beat to death but after going through many of the threads on calibration, I still have a few questions: Assumption: You have already calibrated your system using VE, Avia, or S&V. Question 1: When you play back a DVD at the reference level on your receiver that you used to calibrate, is it theoretically playing back at 105Db? For example, the reference level for calibration on my Yamaha RXV-1200 ended up being -18.5Db when my mains reached 85Db. When I play back a DVD with the receiver volume at -18.5 is it theoretically supposed to be hitting 105DB? Question 2: The Radio Shack SPL is supposed to read about 4Db high so if I measured my sub at 85Db using C weighting and the slow setting, it is actually playing at about 89Db or 4Db hot? Once again, I know these questions have probably been asked more than once but I just want to make sure that I've got it straight. Thanks for everybody's input.