After cycling through the test tones a couple of dozen times, there seems to be a consistent difference of +2-3 db between the left and right sides. If I set the LF at 74-75db, the RF need to be tweaked up a bit to achieve 74-75db as well as the LR. When I cycle back to the LF, it's back up to 78db or so. It seems that when I tweak up the RF and RR to match the left, it also affects the Left side output. The meter is supposedly accurate to +/- 2db @ 114Db however the test is consistently weighted to the left side being +2-3db louder after going through the cycle. It's really weird.