Audio Sync issues From ProTools to FCP 7
Okay, so i'm working on a project that is at 30 frames per second in FCP 7 I will list project details in a moment. My sound designer and I are encountering the issue that when he gives me his Wave bounce from ProTools (HD 8) the audio gradually goes out of sync.
I have looked on this forum and found a few posts about this issue, but nothing that seemed to get to the root of the problem or provide a permanent solution for me.
This is an animation exported out of Flash as a SWF and Wave file, then assembled and rendered out of After Effects (CS5.5) as a ProRes 422 (HQ) QuickTime at 30 fps. This QT is then brought into Final Cut and placed in a sequence (ProRes 422 (HQ) Editing timebase 30, audio 24-bit 48 kHz). I then edit and export a QT from FCP using QT conversion (h.264 30 fps, audio linear PCM 48 kHz sample size 24). The sound designer then creates a ProTools project at 30 fps and imports the QT for sound design. He then bounces a wave file (48 kHz, sample rate 24) which i import into my FCP project and place in the sequence (I do have a countdown and 2 pop to check audio alignment is correct). All seems good at the beginning, but slowly starts to slip out of sync as time goes on.
I have been working this exact way for years on projects that are 29.97, 23.976, 24 fps and never encountered this issue. This is the first 30 fps project though, and I'm a bit confused as to why this is happening. I have found on this forum some workarounds that seem to fix the issue. One is bouncing a QT from protools and using that audio in my FCP project seems to work fine. The other is a free program called Wave Agent where I can set the wave file to be 30 fps and 47952 sample rate which seems to fix the synch issue.
However, I'd prefer not to have to use workarounds and just figure out the root of the problem so we can continue to simply bounce Wave files from ProTools and import into FCP with no synch problems. I believe it is something happening in the ProTools session/bounce, but I don't know ProTools at all. It could also be some simple little thing in FCP that i'm not doing correctly. Either way I'd like to know. Sorry this post is a bit lengthy, but I was trying to provide as much detail as I thought may be needed. If anyone out there has any ideas of where the issue lies and what can be done to remedy it, please let me know. Thank you very much.