Gain filter, Compressor/limiter filter – Apple Final Cut Pro 6 User Manual
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Chapter 8
Using Audio Filters
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Gain Filter
Unlike other audio filters in Final Cut Pro, the Gain filter is applied automatically to
selected clips when you use the Apply Normalization Gain command.
Audio normalization amplifies an audio clip based on its peak (or loudest) value. For
more information about how to use audio normalization, see “
Using Audio Normalization and Gain
The Gain filter has a single parameter (also called Gain) measured in decibel (dB) units.
When the Gain parameter value is positive, the clip audio is amplified. When the Gain
parameter value is negative, the clip’s audio is attenuated. A Gain value of 0 has no effect.
Compressor/Limiter Filter
An audio compressor reduces dynamic range by attenuating parts of a signal above a
certain threshold. Compression is a very important tool because most listening
environments (movie theaters, home stereos, and televisions) have to compete with a
certain amount of ambient noise that must be overcome by the quietest sounds in
your mix. The problem is that if you simply bring up the level of your audio mix to
make the quiet sounds louder, the loud sounds get too loud and distort. By reducing
the level of the loud sounds, you can increase the overall level of the mix, resulting in
higher levels for the quiet parts of the mix and the same levels for the loud parts.
A compressor monitors the incoming audio signal and reduces the signal by a specified
ratio whenever the signal is too strong (as determined by the threshold). Any audio
signal below the threshold is unaffected. Since louder parts get quieter and quiet parts
stay the same, the overall difference between quiet and loud sounds is reduced.
The Final Cut Pro Compressor/Limiter filter allows you to adjust the dynamic range of
an audio clip so that the loudest parts of a clip are reduced while the quieter parts
remain the same.
Before compression
After compression