Having now played my Yamaha CP33 keyboard with the Bose L1 Compact cranked up I realize that some of the piano sounds are much better through the PA than others. Listening through headphones the pianos are all different but sound natural. Played through the Bose the "Grand Piano 1" has a good treble but a deep booming bass that sounds all wrong. On the other hand the "Grand Piano 2" which is a slightly brighter patch, sounds good at both ends and this is the one I am using.

Another difference that I have never noticed before is the way different piano patches respond to large velocity increases. Some patches respond with an abrupt shrill tone while others are much more forgiving to a heavy touch. This isn't apparent when listening through headphones.

I am not sure what all this means but at least I have found a combination that works for me.

Tony