I found Tony's post very interesting, but I'm not sure whether it applies to me because my Bose PAS is the original "Classic" system which actually does have 3 separate amps: one (250 watts) for the top section of the "stick," another 250 watt amp for the bottom section of the "stick," and a third 250 watt amp for the subwoofer. I am running the left and right outputs of my mixer into two separate amps, so I don't think they are being summed, at least not electronically. Granted, there is no stereo separation in the traditional sense of the word; in this case, it's upper and lower rather than left and right, so I guess it's possible that they are being summed in a physical way rather than electronically, but I don't hear this phase cancellation happening on stereo electric piano sounds (see below).

Do you think this stereo issue really matters in my case? Are we even sure that my acoustic piano track is stereo? I don't always use the same Acoustic Piano RealTrack, but they all sound the same to me in this regard. One that I use is 1602:Piano,Acoustic,Rhythm Pop16 Ev. Is this one a stereo track?

For what it's worth, on one song I am using a RealTrack Electric Piano Sound that sounds like it is a stereo recording (~1437:Piano,Electric,Rhythm JazzFunkGroovin Ev16) and it sounds absolutely correct on my Bose system. I hear no phase cancellation on this patch; it sounds totally right.

Thanks,
Jim

Jim
Psalm 33:3 Sing unto him a new song; play skillfully with a loud noise.

BIAB 2018 build 519; Dell Inspiron N4110, Windows 10 64 bit, Intel Core i3-2350m running at 2.29 GHz, Memory: 6 GB DDR3, SDRAM 1MHz