Originally Posted by: Paul 
Thanks for the additional explanations, I can hear what you mean.
The mic signals have not been manipulated, but we will look into the Mid 1 again.
Thanks Paul,
To be clear, this also affects Mid 2.
To test, load only Mid 1 or Mid 2, make sure the Power Panner is neutral (Center C, Width 100%, Balance C) and play a chromatic scale up the keyboard (ideally wearing headphones).
Some examples:-
On Mid 1 C4-C5 are panned slightly left, C#5-B5 panned right, C6-F6 left, F#6 right, G6-B7 left, C8 right. There are problems in the lower register too, but it's easier to hear the higher notes.
On Mid 2, it's most obvious B5-C6, F6-F#6-G6, B7-C8.
I suspect it's just that the L&R Mics got mixed up in some places when the samples were mapped across the keyboard.
Hope this helps!