Imaging and the first violin(s)

If there’s one gremlin in my listening for decades, it has been a certain instability in the image in certain circumstances. I listen to a lot of chamber music, and I’ve noticed that the first violin’s place in the image can get less defined, particularly when the instrument is playing fortissimo. I’ve also noticed it in orchestral music, and sometimes in different ranges of piano recordings - moving from left to right.

I wonder if it is my setup - I’m along the long wall of the room, and while there is lots of space on either side of the speakers, it is not exactly symmetrical. However, I just moved last year, and the shorter and harder side switched from right to left, yet I get the same thing. Three different sets of speakers have exhibited this, and I’ve noticed it auditioning music in dealer showrooms as well (btw, don’t all those speakers standing around play havoc with near term reflections??). I haven’t done enough controlled experimentation, but I do think toe-in ameliorates it a little, but not all together.

I wonder sometimes whether the violins are able to, essentially, cut into the right-aimed microphone at certain levels. Or, I suppose, it could be a frequency-based imbalance in my own right and left ear hearing.

Anybody else notice this sort of thing?