10.6

Table Of Contents
246Logic Pro Effects
Envelope follower parameters
The envelope follower tracks incoming signal levels and generates a control signal that is
used to modulate other Phat FX parameters.
A common use of the envelope follower is to track a sidechain input signal that is used to
control filter parameters.
On/Off button: Enable/disable the envelope follower.
Target pop-up menu: Choose a modulation target from any active effect processor or
master control.
Attack knob: Determine how quickly the envelope follower reacts to rising signal
levels (transients).
Longer attack times result in a slower tracking response to transients—level spikes—of
the input signal. A long attack time on percussive input signals, such as a spoken word
or hi-hat part, translates into a less accurate analysis.
Release knob: Determine how quickly the envelope follower reacts to falling signal
levels, following the initial transient spike.
Longer release times cause the analyzed input signal transients to sustain for a longer
period at the envelope follower output. A long release time on percussive input signals,
such as a spoken word or hi-hat part, translates into a less accurate analysis. Use of
extremely short release times can result in “choppy” sounds, depending on the chosen
modulation target.
Depth knob: Set the modulation amount. This determines the intensity of the control
signal sent from the envelope follower.
At a value of 100%, with a sine wave, white noise, or another signal that frequently
reaches zero dB (and Attack set to zero), the output signal will reach the maximum
amount. Most signals, however, are quieter than this and won’t reach zero dB, so the
extra Depth knob range between 100%-1000% is useful for making the envelope effect
sufficiently sensitive on quieter signals. When loading presets which use the envelope
follower, you should experiment with the Depth parameter.
LFO 1/2 parameters
On/off button: Enable/disable LFO 1 or 2.
Waveform pop-up menu: Set the waveform type used by LFO 1 or 2.
Target pop-up menu: Choose a modulation target from any active effect processor or
master control for LFO 1 or 2.
LFO Rate knob and field: Set the modulation speed of LFO 1 or 2. Values are in hertz—
cycles per second. When the Sync button is on, bar/beat values—synchronized with the
host tempo—are shown.
Sync button: Enable or disable synchronization of LFO 1 or 2 with the host application.
Note: The ability to use synchronous bar values could be used to perform a filter sweep
every four bars on a cycled one-bar percussion part, for example. Alternatively, you
could perform the same filter sweep on every eighth-note triplet within the same
part. Either method can generate interesting results.
Depth knob: Set the amount of LFO 1 or 2 modulation.