Apple Logic Express 7 - Manual (Page 57)

Chapter 8 Modulation 57
Tremolo
The tremolo effect is a cyclic modulation of the amplitude, resulting in periodic volume
changes of. As opposed to the vibrato effect which can be achieved with the
Modulation Delay plug-in, the amplitude (not the frequency) is the modulated
parameter. You’ll recognize this effect from vintage guitar combo amps (where it is
sometimes incorrectly referred to as vibrato).
The intensity of modulation is set with Depth. Rate defines the speed (frequency) of the
modulation. If Symmetry is set to 50% and Smoothing to 0%, the modulation has a
rectangular shape. This means that the timing of the full volume signal is equal to that
of the low volume signal, and that switching between both states occurs abruptly. You
can define the loud/quiet time ratio with Symmetry, and make it fade gently in or out
with Smoothing. Stereophase defines whether the modulation takes place in phase or
out of phase, when in stereo mode. It can be set to any phase angle. When set to out of
phase (
−
180º) the balance wanders from left to right. When set to 180º, left and right
channels are altered in volume simultaneously (in phase).
The graphic display is self-explanatory: All parameters, except modulation speed
(Rate), are displayed.
Spreader
The Spreader plug-in widens the stereo spectrum with an effect that is quite similar to
the Chorus effect. The frequency range of the original signal is periodically shifted in a
non-linear way. In comparison to the Stereo Spread effect, the perceived pitch changes.
Use the LFO Intensity parameter to set the modulation width of the Spreader. LFO Speed
controls the modulation frequency. Channel Delay determines the delay time in
Samples. Mix sets the balance of dry and wet signals.