Why sound is not balanced?

To determine if the preamp is the problem, switch the left input for the right and vice versa. To determine if the amp is the problem, switch the right leads for the left leads. To determine if the speakers are the problem, switch them, placing the current left on the right and right on the left. If the problem persists after these tests, the answer lies with your room. If the room is not symmetrical, identical on left and right because of an odd shape, this is a likely culprit. If the furnishings are different on right and left, (i.e., a big couch on one side and a window on the other) this will cause an imbalance. If you can't do anything about the room, use your balance control to shift more signal to the right speaker until both sides sound identically loud.

That's a great post by Pzuckerman. A very concise troubleshooting guide.

I found a solution to that problem - I didn't have a balance control. I simply moved my listening chair a few inches to the right. If the imaging specificity gets sharper you're good to go. If sharp imaging gets a bit blurred, look for a different solution. FWIW.

A possibility. It happened to me. Same thing - left channel louder than right. It turned out that my left ear is better than my right one. Turn around and face away from your speakers and see if the right speaker (behind you) becomes the louder one. Probably not the case, but it tends to be the last thing you might consider :-) Good luck, Dave

I also recommend Pzuckerman's suggestion as I have a similar problem. I did the same tests and afterwards concluded it must be the room.

Now my room is 18.5 x 15.5 and it is pretty rectangular, but unfortunately I have a huge window on one wall which happens to be the side of the room where the left channel speaker is placed. In addition, the ceiling has dips here and there and the walls are not perfectly level. Bad construction in general. My next step is to try to work with my room treatments to see how best to correct the problem as much as I can.

Adjusting the balance was not helpful in my situation because by the time I found a good setting the center image lost focus.