Apple Final Cut Pro 6 - Manual (Page 325)

324 Part IV Logging, Capturing, and Importing
If the sample rates of all the audio in your sequence match, sample rate conversion is
not necessary and the number of audio tracks that can play in real time increases. If
you are working with someone who is creating music or audio files specifically for your
project, you can request audio files at the settings you need to match your sequence.
However, If your audio clips don’t match your sequence settings, you can improve
audio playback performance by converting your audio files to the sample rate and bit
depth of your sequence.
Converting Audio Clips to Match Sequence Settings
If you are working with preexisting audio material, such as music from audio CDs, you
need to convert the audio files so they match your sequence settings. For example, if
you plan to use a lot of sound effects or music from audio CDs (which have a sample
rate of 44.1 kHz) in a DV sequence with a sample rate of 48 kHz, it’s a good idea to
convert your audio files to a sample rate of 48 kHz.
Most professional video formats, including DV, have a sample rate of 48 kHz and a bit
depth of 16 (this is often abbreviated as 48 kHz/16-bit). Since these settings are so
common for video post-production, they are used for most sequences in Final Cut Pro.
Important: DV sequences sometimes use 32 kHz/12-bit settings, but these settings are
not recommended. As long as you don’t record your DV footage using 32 kHz/12-bit,
you should not use these settings for your sequence.
Audio files can be converted using the Export Using QuickTime Conversion command.
To convert a CD audio file so it matches your sequence settings:
1 Select a sequence, then choose Sequence > Settings.
2 Check the sample rate of the sequence in the Audio Settings area of the General tab,
then click OK.
For DV sequences, the sample rate is usually 48 kHz.
3 Select an audio clip in the Browser that you want to convert to a new sample rate.
4 Choose File > Export > Using QuickTime Conversion.
5 Choose AIFF from the Format pop-up menu.
6 Click Options.
7 In the Sound section of the Movie Settings dialog, click Settings.