Apple Final Cut Express HD - Manual (Page 642)

642 Part VIII Audio Mixing
Using Equalization (EQ) Filters in Final Cut Express HD
All of the Final Cut Express HD EQ filters use a combination of three controls. This
example looks at the Parametric Equalizer filter:
 Frequency: This slider lets you select the audio frequency you want to boost or attenuate.
The lowest available frequency varies from 10 Hz for the High Pass filter, to 80 Hz for the
3 Band Equalizer. The highest available frequency for all EQ filters is 20,000 Hz.
 Q: This setting, when available, allows you to select the range of frequencies
affected. A lower number means a wider frequency range is affected.
 Gain: This setting controls how much you’ll be boosting or attenuating the specified
frequency range.
Compression
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 watches 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 Express HD 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