Exporting audio to OMF

OMF files that you create cannot be larger than 2 gigabytes. In most cases, this should not present a problem because 2 gigabytes will accommodate approximately 7 hours of mono audio media (depending on the bit depth and sample rate of your audio). If your sequence exceeds this limit, you will see a warning message before exporting begins.

http://documentation.apple.com/en/finalcutpro/usermanual/index.html#chapter=60%2 6section=8%26tasks=true

It is a limitation of the format. You will have to ask Avid for the exact technical reasons.

I suppose that you could split the OMF by making two separate sequences at a convenient point and rejoin them when you get the final mix back from the audio people.

Nick Holmes wrote:
I suppose that you could split the OMF by making two separate sequences at a convenient point and rejoin them when you get the final mix back from the audio people.

Exactly.

Another option that I used on a series last year was to export the OMF twice with different tracks selected each time (I had 24 min episodes with 12 tracks of audio in FCP).

ex. OMF #1: I would turn off tracks 7-12 in the FCP timeline & export the full show for tracks 1-6 as one OMF. Then I would turn off the first 6 tracks & turn the last 6 on, then export the second OMF of tracks 7-12.

This is what the post facility asked for & they married the 2 OMFs in their system, so in their Pro Tools project it all mirrored what I had in FCP - an edit with all 12 tracks for the full duration of the program.