Separating Stereo Audio Tracks in FCP For Import into SoundTrack Pro
[This article was first published in the December, 2009, issue of
Larry's Final Cut Pro Newsletter. Click here to subscribe. ]
Ian Hart, from Australia, sent this in:
I have a feeling you’ve treated this a while ago in a Newsletter but I can’t find the answer.
I’m using FCS 2009
On location I record radio mic into Track 1 and a boom mic into Track 2. I capture the sequence with the audio set for discrete tracks, as opposed to stereo. In Final cut pro, everything is as expected, with Track 1 on a1 and Track 2 on a2.
I want to mix the audio from both tracks, but apply some noise reduction to the boom mic (air conditioning) and some equalization to the radio mic.
When I send this sequence to Sound Track Pro, STP Track 1 and STP Track 2 appear as identical stereo tracks with my original RadioMic=Left, BoomMic=Right. I can’t separate the tracks.
If I live with the stereo and apply noise reduction to the Right channel (boom mic) or Equalization to the Left channel (radio mic) the signals are displaced by about a frame and I wind up with an echo.
I’m sure there’s a trick here, but I can’t work it out.
Larry replies: Ian, when you first emailed me, I sent you a long, laborious work-around. Sigh… The answer is actually quite simple.
In Final Cut, a stereo audio pair is linked to each other and, often, to a video clip as well. The odd-numbered audio track is panned left, the even-numbered audio track is panned right and the audio levels of the two clips are linked. However you adjust one, the other moves by the same amount. A good example of when to record using stereo audio is when you are recording music.
The opposite of a stereo audio pair is dual-channel mono. Here, both tracks are panned center and there is no relation between the audio level of one audio clip to the other audio clip. However, both of these audio clips can be linked to a video clip. The best example of when to record using dual-channel mono files are interviews, where the interviewer is on one channel and the guest is on the other channel. You want these linked to the video, but the two audio levels are different.
In Final Cut, if the two tracks are linked as a stereo pair, they will import into STP as a stereo pair. If they are not linked, they come in as mono tracks.
The way you tell is to look at the audio clip. If the two tracks have small green triangles pointing at each other, this means it is a stereo clip and you need to change the clip to dual channel mono to get the import into STP to work correctly.
To do this, select the offending audio clip, or clips, then select Modify > Stereo Pair .
When stereo is unchecked the two tracks import into Soundtrack Pro as separate, mono tracks.