Reverse the channels and see if the imbalance shifts to the other side. If it is a source or something caused by something in the electronics it will change. If it does change then you should be able to find the problen or source of the imbalance. If it doesn't change then you know is is either set up or actually in the recording. BTW, I find a shift to the left quite common when playing solo piano music - I'm sure it just reflects microphone(s) location accurately.
Another test is to find a mono source like an FM radio station or a test set up disc and see if you have a dead center image as you should.
But, all that said, I'd bet it is a set up issue you've yet to deal with. And inches count!
Hope that helps a bit.
Another test is to find a mono source like an FM radio station or a test set up disc and see if you have a dead center image as you should.
But, all that said, I'd bet it is a set up issue you've yet to deal with. And inches count!
Hope that helps a bit.