Apple Final Cut Pro 6 - Manual (Page 851)

66 Part I Audio Mixing
How Linked Mono and Stereo Clips Are Normalized
The Apply Normalization Gain command works differently depending on the type of
clip items selected:
 Single mono clip item or multiple linked mono clip items: A separate Gain filter is
applied to each clip item, and peaks for each clip item are calculated independently.
 Stereo clip items: A stereo Gain filter is applied to the stereo clip items, and the Gain
setting is based on the peak value across both channels.
Reapplying Normalization Gain
Final Cut Pro searches for peak audio only between a clip’s In and Out points, not for
the entire duration of the clip’s media file. If you trim a clip’s In or Out point, new peaks
may be introduced and the Gain adjustment may no longer be appropriate. In this
case, you can easily reapply normalization gain to set an appropriate level.
Reapplying normalization gain is no different from applying normalization gain for the
first time. The only difference is that no new Gain filters are added to clips that already
have them. Instead, the values of the existing Gain filters are adjusted based on the
current audio peaks of the clips.
Choosing Normalization Gain Versus Audio Level Keyframing
The Gain filter and the Apply Normalization Gain command are best used for broad
audio level adjustments, such as when you have clips with fairly low audio levels. For
subtle level adjustments and more complex mixing, you should use audio level
keyframes in the Viewer or Timeline.
Troubleshooting Audio Normalization
There are a few issues to be aware of when you use the Gain filter and the Apply
Normalization Gain command:
 Applying gain raises the level of an audio signal, including the noise. Very quiet
audio, when normalized, may be very noisy. When possible, the best solution is to
rerecord the audio. If this is not possible, you may be able to minimize the noise
using Soundtrack Pro.
 Loud peaks in audio clips that otherwise contain low audio levels make audio
normalization more difficult to use. For example, suppose you have a clip containing
dialogue that was recorded too quietly. At the beginning of this clip, there is a brief
peak when the slate was clapped together. When you attempt to normalize the
audio of this clip, the sound of the slate is so loud that very little gain is applied. To
apply more gain, simply trim the clip until the audio peak from the slate is gone,
then use the Apply Normalization Gain command again.