Odd sync issue with track prints

On a project I just finished I setup print tracks (routed from the stems) and then printed them by setting them to record in real time. Relatively straight forward.

Then I brought these into a new project (where I was doing an Atmos conversion). In my first attempt I simply located the WAV files in the project’s audio folder and re-imported them into the new project, placed them at the same place in the timeline (0:59:20) and proceeded.

However, I was seeing loss of sync. It was good at the beginning and then slipped progressively over the 87min timeline (audio being late relative to picture). Both projects where set at the same frame rate (23.976) and the same sample rate (48kHz), and I verified that the files started on the same timecode in the sequence (0:59:20). But no luck.

Then I went back to the original project and ran a multi-file export of those same stems. Took those files and imported them into the second project at the same timecode, and all was good.

I’m not sure I understand why just importing the WAV file from the recorded print track created a different result than an exported copy of the file when all the settings were identical. Shouldn’t the timing of the file be identical. I know WAV files don’t save timecode per frame, but only for the start of the file and then just follow sample rate. It’s almost like one of those values was mis-interpreted causing the slip.

Any ideas or explanations?

If you really “print” the (i.e. record them in real time), then make sure to use auto punch-in/punch out. Otherwise the actual recording might start a few milliseconds earlier than shown in the active project. This is taken care for by the sync-mark, BTW.

Ah, wasn’t aware of that. Will try that out to confirm that this was my issue.