In every lowpass filter (ES2: Lo mode for Filter 1; Filter 2 is a lowpass filter), all frequency portions above the cutoff frequency are suppressed, or cut off, hence the name. If you’re new to synthesizers and the concepts behind filters, see Synthesizer basics overview.
Cutoff Frequency knob: Control the brilliance of the signal.
In a lowpass filter, the higher the cutoff frequency is set, the higher the frequencies of signals that are allowed to pass.
In a highpass filter, the cutoff frequency determines the point where lower frequencies are suppressed and only upper frequencies are allowed to pass.
In a bandpass/band rejection filter, the cutoff frequency determines the center frequency for the bandpass or band rejection filter.
Resonance knob: Emphasize or suppress portions of the signal above or below the defined cutoff frequency.
In a lowpass filter, Resonance emphasizes or suppresses signals below the cutoff frequency.
In a highpass filter, Resonance emphasizes or suppresses signals above the cutoff frequency.
In bandpass/band rejection filters, resonance emphasizes or suppresses the portions of the signal—the frequency band—that surround the defined frequency, set with the Cutoff Frequency parameter.
The ability to change the Cutoff and Resonance controls at the same time is essential for creating expressive synthesizer sounds.
Drag one of the three chain symbols in the ES2 filter section.
The chain between Cut and Res of Filter 1 controls both the resonance (drag horizontally) and cutoff frequency (drag vertically) simultaneously.
The chain between Cut and Res of Filter 2 controls both the resonance (drag horizontally) and cutoff frequency (drag vertically) simultaneously.
The chain between Filter 1 Cut and Filter 2 Cut controls the cutoff frequency of Filter 1 (drag vertically) and Filter 2 (drag horizontally) simultaneously.