I have finally attempted to hook my Yamaha P90 to the KN6500. I have it set up so that the Technics is the slave. I thought the Yamaha would control the Technics, by that I mean I have both keyboards split at the same location and I thought if I played cords with my left hand on the Yamaha, it would make the background play on the Technics. The only way I get the backgrounds playing is if I play a cord with my left hand on the Technics. Do I have more settings to change?ould play