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EVOC 20 PolySynth Sidechain Analysis Parameters
The parameters in the Sidechain Analysis section control how the input signal is analyzed
and used by the EVOC 20 PolySynth. You should be as precise as possible with these
parameters to ensure the best possible speech intelligibility and accurate tracking.
• Attack knob: Determines how quickly each envelope follower—coupled to each analysis
filter band—reacts to rising signal levels. Longer attack times result in a slower tracking
response to transients—level spikes—of the analysis input signal. A long attack time
on percussive input signals—a spoken word or hi-hat part, for example—will translate
into a less articulated vocoder effect. Therefore, you should set the Attack parameter
to the lowest possible value to enhance articulation.
• Release knob: Determines how quickly each envelope follower—coupled to each analysis
filter band—reacts to falling signal levels. Longer release times cause the analysis input
signal transients to sustain for a longer period at the vocoder’s output. A long release
time on percussive input signals—a spoken word or hi-hat part, for example—will
translate into a less articulated vocoder effect. Use of extremely short release times
results in rough, grainy vocoder sounds. Release values of around 8 to 10 ms are useful
starting points
• Freeze button: This parameter, when enabled, holds—or freezes—the current analysis
sound spectrum indefinitely. While Freeze is enabled, the analysis filter bank ignores
the input source, and the Attack and Release knobs have no effect. See Freezing the
EVOC 20 PolySynth’s Input Signal.
• Bands field: Determines the number—up to 20—of frequency bands that are used by
the filter banks. See Setting the Number of EVOC 20 PolySynth Filter Bank Bands.
Freezing the EVOC 20 PolySynth’s Input Signal
The Freeze button in the Sidechain Analysis section of the EVOC20 PolySynth freezes the
sound spectrum of the analysis input signal.
143Chapter 7 EVOC 20 PolySynth