User Guide

FXAlg #900: Env Follow Filt
Algorithm Reference-117
The attack and release rates of the envelope follower are adjustable. The rates are expressed in decibels per second
(dB/s). The envelope may be smoothed by a lopass filter which can extend the attack and release times of the
envelope follower. A level meter with a threshold marker is provided.
Parameters:
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Wet/Dry The amount of modulated (wet) signal relative to unaffected (dry) signal as a percent.
Out Gain The overall gain or amplitude at the output of the effect.
FilterType The type of resonant Þlter to be used. May be one of ÒLowpassÓ, ÒHighpassÓ,
ÒBandpassÓ, or ÒNotchÓ.
Min Freq The base frequency of the resonant Þlter. The Þlter resonant frequency is set to the Min
Freq while the signal envelope is at its minimum level or below the threshold.
Freq Sweep How far the Þlter frequency can change from the Min Freq setting as the envelope
amplitude changes. Freq Sweep may be positive or negative so the Þlter frequency can
rise above or fall below the Min Freq setting.
Resonance The resonance level of the resonant Þlter. Resonance sets the level of the resonant peak.
In the notch Þlter, this sets the amount of cut, so 0 dB provides the highest, widest notch,
and higher levels make the notch increasingly narrower and shallower.
Threshold Represents the level above which signal envelope must rise before the Þlter begins to
follow the envelope. Below the threshold, the Þlter resonant frequency will remain at the
Min frequency.
Atk Rate Adjusts the upward slew rate of the envelope detector.
Rel Rate Adjusts the downward slew rate of the envelope detector.
Smth Rate Smooths the output of the envelope follower. Smoothing slows down the envelope
follower and can dominate the attack and release rates if set to a lower rate than either of
these parameters.
Wet/Dry 0 to 100%wet Out Gain Off, -79.0 to 24.0 dB
FilterType Lowpass Min Freq 16 to 8372 Hz
F Freq Sweep -100 to 100%
0Hz 2k 4k 6k Resonance 0 to 50 dB
Threshold -79.0 to 0.0 dB Atk Rate 0.0 to 300.0 dB/s
Rel Rate 0.0 to 300.0 dB/s
Smth Rate 0.0 to 300.0 dB/s
E
-dB 60 40 * 16 * 8 4 0