Originally Posted by Roger Dressler
Next time you feel the left side bias, turn your head around to face the rear for a moment to see if it stays that way or not.
Your brain will fool you if you try it that way.
You can do the same test using an SPL meter and listening for a difference in left and right surround, then verifying with the meter. If you find that your right "sounds" a little lower, then go by ear to raise the right a couple of dB to compensate. No rule says you can't.
Then listen to a passage or two you know well .
What you describe can also be caused by not having quite the correct relative levels between the side surround and the back surround on the same side. If you simultaneously send both speakers a mono test tone, a phantom image should be centered between the two. BUT, you must evaluate that phantom position while facing the screen
. Our perception of location of sound behind us is different than when we face it.
A good test example is from Oblivion. If you use the scene in Oblivion where the bubblecraft lands at the stadium, the sound should move smoothly in a counter clockwise manner to the rear half of the room as the craft leaves screen left. If it sounds like it goes straight to the rear rather than strongly around your left side, then the left surround is too low relative to the back left channel. Check your levels...as described above if necessary.
Then run the scene again to verify.
When the drone leaves the stadium, it zooms out the right side and rear quite aggressively.
Your back surrounds are not in the back corners, right?