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Table Of Contents
BR: (band rejection):The frequency band directly surrounding the cutoff frequency is
rejected, whereas the frequencies outside this band can pass. The Resonance parameter
controls the width of the rejected frequency band.
BP (bandpass): The frequency band directly surrounding the cutoff frequency is allowed
to pass. All other frequencies are cut. The Resonance parameter controls the width of
the frequency band. The bandpass filter is a two-pole filter with a slope of 6 dB/octave
on each side of the center frequency of the band.
Setting Filter 2’s Slope in the ES2
Most filters do not completely suppress the portion of the signal that falls outside the
frequency range defined by the Cutoff parameter. The slope, or curve, chosen for Filter 2
expresses the amount of rejection below the cutoff frequency in decibels per octave.
Filter 2 offers three different slopes: 12 dB, 18 dB, and 24 dB per octave. The steeper the
slope, the more severely the level of signals below the cutoff frequency are affected in
each octave.
The Fat setting also provides 24 dB per octave of rejection but features a built-in
compensation circuit that retains the “bottom end” of the sound. The standard 24 dB
setting tends to make lower end sounds somewhat “thin.” See Getting to Know the
ES2 Oscillators.
Using the ES2 Filter Cutoff and Resonance Parameters
In every lowpass filter (in the 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.
68 Chapter 5 ES2