E-Mu ProteusX, Operation Manual

Page: 118 / 188

7 - Effects
Effects Descriptions
118 Proteus X Operation Manual
Chorus
Background: Chorus
An audio delay in the range of 15-20 milliseconds is too short to be an echo, but is
perceived by the ear as a distinctly separate sound. If we now vary the delay time in this
range, an effect called chorus is created, which gives the illusion of multiple sound
sources. A slight amount of feedback serves to increase the effect. Inverted feedback
percentages add negative feedback which can change the tone of the chorus. A very slow
LFO rate is usually best for a realistic effect, but a faster LFO rate can also be useful with
minimal LFO depth (.2).
This effect is a true-stereo chorus with independent delay lines for the left and right
channels. The left and right modulation waveforms are always 180° out of phase, so
that left channel delay is increasing while the right channel delay is decreasing and vice-
versa. This creates a richer and more animated chorus sound.
Modulation Parameters
•
Wet/Dry Mix
•
Rate (LFO)
•
Feedback
Parameter Description
Initial Delay Sets the length of the delay. Range: 10ms to 50ms.
Modulation
Depth Sets how much the LFO affects the delay time. Increases the
animation and amount of the chorus effect. Range: 0% to 100%
Modulation
Rate Sets the frequency of the low frequency oscillator.
Range: .01Hz to 15Hz
Feedback Sets the polarity and amount of delayed signal that will be recirculated
through the delay lines. Range: -99% to +99%
LFO Waveform Selectable between Sine or Triangle wave.