Tascam DR-40 Sync Drift / FCPX Audio Fix Missing

I was editing an hour+ long performance video in FCPX using audio from both an audience mic into a camera, and audio from the front-of-house board recorded on a Tascam DR-40.  I synced everything with PluralEyes, but I noticed an echo toward the end.   Zooming in to the waveforms I could see that the two audio tracks were in sync at the beginning, but slightly out of sync after an hour.

I couldn’t find a way to change the speed of the Tascam track in FCPX.  In FCP7 there’s a Change Speed feature where you can input the percentage or duration change down to 3 decimal points.  I searched the forums and blogs and it looks like FCPX can’t do it.

I went back to FCP7 and re-synced everything there.  Zooming in tight to the waveforms and using Modify: Change Speed (command + J) I adjusted the speed of the track with trial & error until it matched up.  Speed change was 100.008 percent.

Out of curiosity I ran a test with a Sony HDR-AX2000 camera, a Zoom H4n and the Tascam DR-40.  I found that the Tascam track was 9 frames slower than the audio from my camera after one hour.

Sync Drift After One Hour: Tascam +9 Frames, Zoom +2 Frames

Interestingly, the Zoom H4n was 2 frames off too, so eventually it would also need to be adjusted.  But at one hour the sync difference was not noticeable.

I went to Change Speed and entered 100.008 %, re-synced at the beginning and got the Tascam track to within 1/2 frame.

Sync After Speed Change

Interestingly, I couldn’t change the speed of the Zoom track less than 100.005%, so it couldn’t be improved.

So for sequences of less than 15 minutes or so the Tascam should be ok, but for long form shoots (which I do a lot of) it’s kind of a pain.  As much as I like the DR-40 (for the line/mic switch, the locking XLRs, and light weight) I think I’ll have to get rid of it and stick with the Zoom H4n.

5 thoughts on “Tascam DR-40 Sync Drift / FCPX Audio Fix Missing

  1. I have also had terrible luck using various audio recording devices and syncing with video on concerts longer than an hour. The audio recorder I have is higher quality than my cameras so I’m blaming the cameras. You can see all the dirty details on this webpage created for a masters program in Indiana:

    https://sites.google.com/site/536iupui/home/case-studies/record-edit-publish-live-performance

    I’m interested to know how you’re going to fix this. Thanks for keeping this blog, interesting stuff you’re doing

    • That’s unfortunate you had so much trouble, especially with such a high-end audio recorder. I’m not sure you should blame the cameras though, except maybe the Flip which is recording audio at a different sample rate. I shoot with a lot of different video cameras and DSLRs, and I’ve never had any issues with the cameras syncing to each other as long as they are set to the same frame rate (color matching is another matter). But the external audio recorders must use a different internal clock or something because every recorder I’ve tried goes at a slightly different speed. I know it’s possible to upgrade to equipment that will sync to timecode for both audio & video but the cost is prohibitive. For me the Zoom H4n syncs up the best with only about a 2 frame drift after an hour which I can live with.

  2. In case anyone else seems to have a problem. I shot video on the Canon 60D and the 5D. I used the H4N Zoom to record audio. When I dealt with the files natively as Quicktime (.mov) files, the audio and video synced up beautifully in the timelines of both Premiere Pro and After Effects. However, when I exported the finished project or rendered it, audio and video were not synced.

    After much experimentation the best result was yielded by the following.

    Instead of dealing with the .mov files natively from the camera, I transcoded them first using the Cineform Neoscene codec. Once I did that, I combined the video with the audio from the H4N Zoom. I could then export or render both audio and video to a variety of settings without experiencing any type of sync issue.

    I don’t know why this solved the problem but it made me think that there was an issue with the way that Premiere and After Effects treat the native Canon files that leads to them not being able to sync up with audio after export and rendering. It’s a very strange phenomenon indeed that they sync perfectly on the timeline but don’t sync after rendering and exporting.

  3. Having both a Tascam DR-100 and a Zoom H4N, I have noticed that on long audio recordings 45 minutes+ there is a noticeable difference between the recording speeds. It’s extremely subtle but you’ll start to hear an echo/delay between the two audio devices if you are recording the same event/content.

    For an hour long recording I was able to fix this issue by very very slightly slowing down the H4N clip in Audition. With a little experimentation and a tiny subframe shift, I was able to get the two tracks perfectly synchronized. Hope this helps anyone having a similar issue.

  4. Yes have got this problem too..wildtrack recordings of a concert video over 60 mins continuous shoot length found both camera sound , Zoom R16 multi track were still together, and TascamDR40 (used for audience etc pick up) had drifted by about 10 frames (longer) from start recording at 44.1 (native).
    Did similar recently for a drama shoot and used 48K which was about 4 frames out (longer audio track).
    Using Premier Pro I just time shift the wild track DR 40 track to fit the camera pick up sound, thus restore lip sync, fine on speech but used time shift, pitch fixed, (within Audition) for the music to be sure.. takes longer to get right in sync again.
    The strange thing is I have done several video/ audio shoots this way with the DR40, avoiding difficult cable routes from stage etc to camera and have only recently found this time drift.. hence started to search for a solution.
    I wonder if The DR40′ s clock is a bit temperature sensitive. The auditorium was very warm for the concert.
    Also need to experiment if the higher clock speed improves drift.. basically the clock runs slowly it would seem.
    \The camera/s seem to stay together as did the Zoom multi track over an hour continuous.. seems I am not alone though with this problem and that’s why pro gear syncs clock together.. still a great piece of audio kit though.

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