One speaker is louder than the other

Are you sure both drivers in the low volume speaker are functioning (ear next to driver with low volume music. I had a similar problem and one tweeter was blown.

I had that problem before I moved and then it disappeared when I moved to a different house. Besides the change in rooms, the cables were switched during the move. Have you tried switching the cables? Stranger things have happened in this crazy hobby.

switch loudspeakers from left to right see if problems follows loudspeaker if so its in the speaker not the system.

I think I have found the problem. the surrounds on both speakers are cracking and is worse on the right side. Plan to get them repaired this week.

"...I think I have found the problem. the surrounds on both speakers are cracking and is worse on the right side. Plan to get them repaired this week....."

That will do it. Let us know what happens after the repair.