Fine UD: you want to be the "High Priest of Mono" then that's your choice, but everything you said about mono ain't the gospel truth. The engineers at Bose at trying Yamaha P250's on their mono Bose PAS systems and are finding that summing the mono signal causes phase problems. Forget how crowded the room is or isn't - phase problems will cancel part of the sound BEFORE it ever gets to your audience. They actually think you should use the mono XG piano samples instead of the signature stereo sounds of the P250, or buy two PAS systems of course, to avoid this. But they only invented your PAS system so what do they know?

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