There may actually be one. If Cantabile is saving audio as multi-channel wave files, there is an easy drag-and-drop way to quickly extract the two relevant channels as a stereo file.
I built another little utility some time ago to help me handle the multi-channel wave files my DL32R mixer creates when recording rehearsals. Since they are a mix of stereo and mono channels, simply extracting all individual channels is not much use to me, so I built a front-end for the tool SOX to de-multiplex multi-channel .WAVs to customized configurations called “profiles”.
Have a look here - and give me a shout when you need more information!
In your case, you would simply need to create a profile that extracts only channels 12 and 13, so it would only consist of one line:
Main Mix, 12 13
Put this line into a text file, call it “Rehearsal Main Mix.txt” or similar and put the file into the Audio Demuxer profiles folder. Now, drop your recorded .wav file into the Audio Demuxer window, select your “Rehearsal Main Mix” profile and click “Process”. You’ll get a shiny new stereo file containing just your main mix. Now you can play it in any media player that plays stereo wave files.
Hope this helps!
Cheers,
Torsten