1 - Remove / rename any MIDI files to avoid synchronized play.
2 - Disable this feature by typing the following command from the terminal and then restarting QMidi:
defaults write com.mixage.qmidipro disableSlaveMIDIFileLinking YES
What audio interface are you using, Claude? How much off is the sync? Is it exactly the same for every file?
If you are using a Mac’s built-in audio, audio latency can be as much as 60msec compared to virtually instant for USB MIDI.
Also, is the audio file directly recorded from the MIDI file? Was there any trimming of the audio file during the recording? Do they both start on the first note?
Having a MIDI file play in sync with your audio could be very useful, to control lighting, vocal effects, send patch changes to keyboards or guitar processors you might also be playing with. Not to mention many digital mixers have MIDI control…