Do I have a "balance" problem?

Does your system occupy a rack or cabinet in between your speakers and, if so, how far away from the front wall are your speakers? Even if you don't normally have domestic permission to move the speakers out as far as 1/4 the distance from the front wall to the rear wall (a usual recommendation), it might be worthwhile to try them there temporarily to see if what you're dealing with is a sonic reflection off of an object located between the speakers.

If the above doesn't apply to you, then also, sometimes, construction variations within the walls of your room can lead to the acoustic center of your room not lining up with the mathematical center of the room (laterally). You may want to try differing sets of speaker positions left to right with respect to the midway point between the side walls...just to see if it has any impact on the problem or if a new lateral position for your speaker pair can be found that fixes the problem. In the end don't be afraid to try experimenting with longer or shorter distances between the speakers as well, but you can start with keeping it the same as it is now, for simplicity's sake.

In any case, this sort of problem is almost always fixable if you stay with it, so keep experimenting. Regards. John

Might just be wax buildup in ears. Doc can clean properly.

****construction variations within the walls of your room can lead to the
acoustic center of your room not lining up with the mathematical center of
the room (laterally)****

Ivan is correct. In my dedicated room, one speaker is placed along a very
thick, brick load-bearing wall; the other speaker is placed along an inside
non-load-bearing wall which (to make matters worse) has a built-in closet.
No amount of room treatment has corrected what is, basically, two different
sounding halfs of the room. The side with the built-in closet is much more
resonant than the other and tends to make center images "pull"
to that side.

Finessing speaker placement has helped a great deal. Placing your
speakers to be equidistant to your listening position may not be the best
approach. Try moving one slightly forward or backward relative to the other
(the speaker's dispersion characteristics will determine which), and play
with toe-in of one or both speakers. It may not be a perfect solution, but you
can certainly help the situation this way. I have even used tubes that I know
to have slightly reduced gain in one of my amps to compensate. I don't
have a balance control on my preamp. Good luck

If you have access to other systems (friends or stores) you can listen to those to see if you experience the same center image issues. That'd be a quick way to determine if it's your ears or not.

I'm fanatical about getting that center image locked in the right place. A few notes...it doesn't take much in some rooms to throw it off. Just a small piece of furniture or a painting on the wall in a certain spot can really pull an image off to one side. Also, it'll vary on some recordings and even a little from track to track at times.

Good luck in getting it sorted out. Let us know the outcome.