As far as the Bose is concerned, rockstar_not is correct, the Bose is quite bass heavy when I play recorded music through it at home. It actually like the overall balance in this situation and I would probably adjust a sound system to sound the same. However when I listen to my piano in this situation the bass/treble balance isn't right for a realistic piano sound. I understand how this should be different in a larger space and I will be auditioning my system at the venue in the next few days.

I now realize that the way my piano sounds when forcing stereo to mono is another issue and has nothing to do with the Bose or the mixer. Whenever I combine piano channels in a stereo to mono adapter the piano sounds thin, as Mac aptly describes it. If I input both piano channels to the mixer or Bose via the phono stereo inputs, the piano sounds "right" (although bass heavy from the Bose)

Thanks for the discussion, there is more to this sound mixing than I realized.

BTW, my first gig isn't anything very grand - just playing for background and dancing at our campground/retirement community in Florida. Our home is a 37ft 5th wheel which may account for the way the Bose sounds!!

Tony