To control the Yamaha CS1x externally using CC messages, refer to the Yamaha CS1x data list manual. Assign available CCs from your controller to the CS1x controls using Bome's Translator. The NRPN message "FILTER CUTOFF FREQ. BnH,63H,01H,62H,20H,06H,mmH" controls the filter cutoff frequency. For an incoming message "B0 09 xx" (CC 9), the outgoing message for CS1x on channel 1 would be "B0 63 01 62 20 06 xx." "n" in Bn (controller) represents the MIDI channel. Consult the manual's receive flow section and follow the arrows for better understanding. For more guidance, refer to Yamaha's customer support or documentation.