I spend a lot of time positioning the speakers. By nature these require very precise direction. Not just vertically but they have to be within 1deg horizontally relative to my listening position or even less. The image lives within that 1deg sweet spot. Just putting pressure on the speaker in an effort to turn it will ruin the image. When it's there it's beautiful, when it's not it's obvious.
Yes, I can't say it's not my ears. But it is a slight off center shift and I do suspect the asymmetry of the room. Especially that interior corner adjacent to the right speaker. It's probably acting like a horn. However if I close my eyes it's gone so not enough to get up out of my chair and move things around. The room's been in this arrangement for 20 years now. It's the best it can be.
Thanks all for your help.
I too have that stage left issue. Not equipment problems as many of us have found. I agree with many here, it's the non symmetrical room. I believe that electronic manipulation might help but the acoustic properties are the key. Work to acoustically balance the sound.
I have had a balance problem for several years, and yes, my room is not symmetrical. I have tried all sorts, but I recently went for a hearing test, and my right ear now has a drop, but not at all frequencies. I do use a balance control, but the image varies with frequency and volume. If I turn my back, the sound pulls the other way! So unless I set my DSP differently for each channel, I will have to live with that.
When other people ask about balance problems I always suggest turning around and listening, but no one seems to have tried it. Too simple, perhaps?
You can try that with the DSP and when adjusting most of the stereo image response is from 200hz to 5khz rather then the very top end or bottom end.
Panel speakers sound have a tendency to be directionally sensitive. Also what's behind them is possibly contributing reflective sound. That requires more or less perfect symmetry for a perfect soundstage.
Early reflections and... no joke, ear wax. I hope the moderators forgive me for being too personal... but I have ear wax problems and any delay in my regimen of using lotion soap and shower head for 30 seconds in each ear starts turning the stereo image to one side. Usually to the left.
Another thing that changes with frequency and volume is the impact of diffracted energy. Reflected too, as has been mentioned.
If you have a wall on one side and it's more open on the other, so the other travels further before getting back to you, try absorbing the closer wall.