Filters; Resonant Filter; Envelope Filter; Triggered Filter - Kurzweil Flash Play PC4 Musician's Manual

The Effects Chain Editor
Effects Parameters

Filters

Resonant Filter

Frequency (or Freq) is the fixed resonant frequency of the filter. Its range is 16 to 8372 Hz.

Envelope Filter

Envelope Filter is a resonant filter whose center frequency can be made to vary according to
the level of the incoming signal.
There are four types of Resonant Filter effects in the PC4. All of them have these parameters
in common:
Filter Type (or FiltType) can be Lowpass, Highpass, Bandpass, or Notch (band-cut).
Resonance is the resonance of the filter, adjustable from 0 to 50 dB.
Filter Type can be Lowpass, Highpass, Bandpass, or Notch (band-cut).
Min Freq is the minimum resonant frequency of the filter, that is, the filter frequency when
the input gain is below the triggering threshold. Its range is 16 to 8372 Hz.
Sweep determines how far the resonant frequency moves when the input level increases.
At positive levels it moves up in pitch, and at negative levels it moves down. The highest
possible resonant frequency is 8372 Hz, the lowest is 0 Hz. This parameter's range is -100%
to +100%.
Resonance is the resonance of the filter, adjustable from 0 to 50 dB.
Atk Rate adjusts the upward slew of the attack portion of the envelope detector. Range is 0
to 300.0 dB/sec.
Rel Rate adjusts the downward slew of the release portion. Range is 0 to 300.0 dB/sec.
Smooth Rate slows down the envelope follower. If it is set to a lower rate than Atk Rate or
Rel Rate, it can dominate those parameters. Range is 0 to 300.0 dB/sec.

Triggered Filter

The Triggered Filter is a sweeping resonant filter that triggers when a certain input threshold
is reached, and then follows its own envelope, consisting of an instantaneous attack and an
exponential release, rather than the envelope of the input signal.
Max Freq is the resonant frequency of the filter at the peak of the internal envelope. It can
be set lower than Min Freq (above), in which case the filter will sweep downwards, then back
up. Range is 16 to 8372 Hz.
Trigger is the input-signal threshold at which the envelope detector triggers. Range is -79 to
0 dB.
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