Soundtrack Pro 3 Effects Reference (en).pdf - Help Library - Apple

Filter Effects 5
Filters are used to emphasize or suppress frequencies in an audio signal, resulting in a
change to the tonal color of the audio.
Soundtrack Pro contains a variety of advanced filter-based effects that you can use to
creatively modify your audio. These effects are most often used to radically alter the
frequency spectrum of a sound or mix.
Note: Equalizers (EQs) are special types of filters. Typically, they are not used as “effects”
per se, but as tools to refine the frequency spectrum of a sound or mix.
This chapter covers the following:
• AutoFilter (p. 77)
• Soundtrack Pro Autofilter (p. 82)
• Spectral Gate (p. 82)
AutoFilter
The AutoFilter is a versatile filter effect with several unique features. You can use it to
create classic, analog-style synthesizer effects, or as a tool for creative sound design.
The effect works by analyzing incoming signal levels through use of a threshold parameter.
Any signal level that exceeds the threshold is used as a trigger for a synthesizer-style
ADSR envelope or an LFO (low frequency oscillator). These control sources are used to
dynamically modulate the filter cutoff.
The AutoFilter allows you to choose between different filter types and slopes, control the
amount of resonance, add distortion for more aggressive sounds, and mix the original,
dry signal with the processed signal.
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