I fooled around with the QS8s last night. First I angled them so they were crossways to the corner and pointing to the middle of the room. Lost some audio.
Then I took Alan's advice and set them against the sidewall, but moved them to the very edge of the shelf, about 4 inches from the rear wall. What a difference for such a small adjustment! I measured with my SPL meter and this little change necessitated recalibration as it made a 4-5 dB difference. I believe thay will stay there as they sound terrific now. Thanks to all who input.
