System information
30 Lowpass
Dave Smith Instruments
Lowpass
Frequency: 0...164—Sets the lter
cutoff frequency over a range of
more than 13 octaves. This control
steps in semitones when turned
slowly, but smoothly controls the
lter without steps when turned at a
faster rate.
4 Pole:
On, Off
—Selects the lter conguration. When on, the lter is in 4-pole
mode. A 4-pole, low-pass lter rolls off frequencies above the cutoff frequency at
a slope of -24dB/octave. When off, the lter is in 2-pole mode and has a slope of
-12dB/octave and a more gradual roll-off of the higher frequencies.
Resonance:
0...127
—Emphasizes a narrow band of frequencies around the
cutoff frequency. In 4-pole mode, high levels of resonance can cause the lter to
self oscillate. In 2-pole mode, resonance is much more subtle.
Audio Mod:
0...127
—Controls the amount of audio from oscillator 1 used
to modulate the lter cutoff frequency. For lter-only audio, set 1/2 MiX in the
Oscillators section to 0/100, oscillator 2 Shape to Off, and oscillator 1 Shape to
the desired waveshape. This is useful for bell-like FM sounds. A wide range of
sounds can also be made using audio Mod with the oscillators routed normally
through the lter.
Key > Freq:
0...127
—Sets the amount of modulation from the note number—
from either the beat, the pads, or via MIDI—to the lter frequency. Sometimes
called key tracking in keyboard synths, because the cutoff frequency “tracks”
notes played on the keyboard. A setting of 64 will step the lter in semitone
increments for each successive note, 32 is quarter tones, and so on.