CE is right in a sense about altered music masters.

However as I remember it, they only mess around with the super extreme signal ranges, like below 80hz and above 15khz and a slight gain in the vocal frequencies. Mostly this is recently and to help those out that go the $20 bombox route.

Once you get into stuff like 1ctobar has this point becomes moot. It sounds as though with the seperation that he has it wouldnt even matter in the first place. Everything is so pieced out that he wouldnt even notice a gain or cut in signal. Besides I believe that reciever, as he stated has a feature that pretty much eliminates any problems from cuts and gains.

EQs are more for Personal hearing prefrence rather then objective reconstruction. Individual results vary greatly.