Because the REAC SONAR computer is always configured as a SPLIT location, it cannot send REAC ports back into the V-Mixing system. We understand your desire to have multichannel playback in your system, but for REAC SONAR cannot do it via REAC. You can either employ a third party multichannel WAV playback device feeding into the analog inputs of your V-MIX system, or you can employ a multichannel audio interface to play back your SONAR projects into the analog inputs ports of your V-MIX system.