By the way, the Bose L1 Compact has no built-in EQ system - it all must be done either with a mixer or on the keyboard.
I think the Bose systems all come pre-EQ'd with that 'smiley' contour. In fact many of my friends have this poem memorized...
All highs, all lows,
No mids, that's Bose!
If you put a 'smiley' EQ'd keyboard into a smiley EQ'd PA, you are going to get mud and brittle highs! I'd simply take the mastering presets down a notch across the board... But don't forget, there are TWO Mastering sections... One for the Style/SMF, and one for the Keyboard Parts. Remember to change BOTH!