Apple Final Cut Pro 7 - Manual (Page 874)

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.
What Reference Level Should You Use for Mixing and Output?
The dynamic range of your mix is dependent on the final viewing environment. For
example, movie theaters have large, relatively expensive sound systems that can reproduce
a large dynamic range. Television speakers are much smaller, and often the listening
environment has more ambient noise, so very quiet sounds may not even be noticeable
unless the overall signal is compressed and the level increased, reducing the dynamic
range.
For example, television stations normally accommodate only 6 dB between the average
loudness and the peaks. Dolby Digital feature film soundtracks, on the other hand, can
accommodate up to 20 dB between average and peak levels. This is why loud sounds in
a movie theater sound so loud: they are much louder than the average level.
874 Chapter 54 Evaluating Levels with Audio Meters