3.5

190MainStage Instruments
Filter parameters
• Cutoff slider: Set the cutoff frequency of the lowpass filter.
• Resonance slider: Cut or boost the portions of the signal that surround the frequency
defined by the Cutoff parameter. Boost can be set so intensively that the filter begins to
oscillate by itself (see Overdrive the MainStage ES1 filter).
Tip: You can simultaneously adjust the cutoff frequency and resonance parameters
by dragging vertically (cutoff) or horizontally (resonance) on the word Filter, found in
the center of the black circle.
• Slope buttons: The lowpass filter offers four different slopes of band rejection above
the cutoff frequency. Click one of the buttons to choose a slope (amount of rejection,
expressed in decibels (dB) per octave):
• 24dB classic: Mimics the behavior of a Moog filter. Increase the Resonance
parameter value to reduce the low end of the signal.
• 24dB fat: Compensates for the reduction of low frequency content caused by high
Resonance values. This resembles the behavior of an Oberheim filter.
• 12dB: Provides a soft, smooth sound that is reminiscent of the early Oberheim SEM
synthesizer.
• 18dB: Resembles the filter sound of the Roland TB-303.
• Drive slider: Change the behavior of the Resonance parameter, which eventually distorts
the sound of the waveform. Drive is actually an input level control, which allows you to
overdrive the filter.
• Key slider: Set the effect that keyboard pitch (the note number) has on filter cutoff
frequency modulation.
• If Key is set to zero, the cutoff frequency does not change, no matter which key you
strike. This makes the lower notes sound comparatively brighter than higher notes.
• If Key is set to maximum, the filter follows the pitch, resulting in a constant
relationship between cutoff frequency and pitch. This mirrors the properties of many
acoustic instruments, where higher notes sound both brighter in tone and higher in
pitch.
• ADSR via Vel sliders: Drag to determine how note velocity affects modulation of the
filter cutoff frequency with the envelope generator. See MainStage ES1 envelope
parameters overview.
• Filter Boost button (Extended Parameters area): Increase the output of the filter
by approximately 10 decibels. The filter input has a corresponding decrease of
approximately 10 decibels, maintaining the overall level. This parameter is particularly
useful when applying high Resonance values. See Overdrive the MainStage ES1 filter.
Overdrive the MainStage ES1 filter
If you increase the filter Resonance parameter to higher values, the filter begins to
internally feed back and, as a consequence, begins to self-oscillate. This results in a sine
oscillation—a sine wave—that is actually audible.
You can make the ES1 filter output a sine wave by following the steps below. This lets you
play the filter-generated sine wave with the keyboard.