Apple Final Cut Pro 7 - Manual (Page 308)

About Audio Peaks
When you capture audio, clipping occurs if any part of the audio signal goes over 0 dBFS.
Because 0 dBFS is the maximum digital level possible, all levels that would have been
above 0 dBFS are set to the maximum audio level, causing clipping. Due to the nature
of digital audio recording, such clipped audio typically results in a crackly, brittle-sounding
clip that is unsuitable for use. All occurrences of clipped audio appear as 0 dBFS peaks.
Excessive peaks indicate that your audio was recorded at unsuitable levels.
Final Cut Pro alerts you when an audio channel is peaking by lighting up its peak indicator
in the Clip Settings tab of the Log and Capture window. If the peak indicator is lit, you
should reduce the gain for that channel on your audio interface.
If you have already captured a clip and it has peaks in the audio, you can either recapture
the audio at a better level or edit the audio appropriately to avoid the peaks. You can
use the Mark Audio Peaks command to identify audio peaks in clips or sequences. It’s
then up to you to decide whether to avoid using those sections of audio or rerecord
them. For detailed information about the Mark Audio Peaks command, see
“Evaluating
Levels with Audio Meters.”
Capturing Audio from an Audio Deck Using Device Control
Final Cut Pro allows you to capture audio from a device-controllable audio deck such as
a professional DAT (digital audio tape) deck or a digital multitrack recorder. This is mainly
useful when capturing audio that was acquired via dual system recording, in which video
and audio were recorded simultaneously to different devices.
As with capturing video, your audio tapes must have timecode recorded on them or you
cannot set In and Out points for capture. Audio decks may be controllable if they use one
of the standard device control protocols (typically, RS-422) supported by Final Cut Pro.
If you’re planning to capture dual system audio using device control, make sure that your
audio deck is genlocked with the audio or video interface you are using for capture. For
more information on connecting a device-controllable audio deck to your computer, see
“Connecting Professional Audio Devices.” For more information on capturing synchronized
audio, see “Capture Settings and Presets.”
To capture audio from an audio-only device using device control
1 Choose File > Log and Capture (or press Command-8), then click the Capture Settings
tab.
2 Choose the appropriate device control preset from the Device Control pop-up menu.
308 Chapter 19 Capturing Audio from Tape