The Kyma Language for Sound Design, Version 4.5

Filter
Filters Category
An IIR filter of the specified type, cutoff frequency, and order with gain or attenuation on the input and an
attenuator on the amount of feedback.
Input
This is the Sound to be filtered.
Type
Choose:
LowPass to attenuate all frequencies above the cutoff Frequency.
HighPass to attenuate all frequencies below the cutoff Frequency.
AllPass to allow all frequencies to pass through unattenuated (but phase shifted by (-90 * Order) degrees
at the specified Frequency, with smaller phase shifts at frequencies below that and larger ones for
frequencies above).
Frequency
The cutoff frequency for the filter can be specified in units of pitch or frequency. When Feedback is close
to 1, the filter will tend "ring" at this frequency. The following are all ways to specify the A above middle
C:
440 hz (in hertz or cycles per second)
4 a (as the 4th octave A)
69 nn (as a MIDI notenumber)
4 c + 9 nn (as 9 half steps above middle C)
1.0 / 0.00227273 s (inverse of a period at 44.1 kHz sample rate)
The following are examples of how to control the frequency using MIDI, the virtual control surface, or a
third-party program:
!Pitch (key number plus pitch bend)
!KeyNumber nn (MIDI notenumber)
4 c + (!Frequency * 9 nn) (continuous controller from 4 c to 4 a)
Q
Q is related to Bandwidth.
For AllPass filters, this affects the size of the phase shift on frequencies around the center Frequency
(higher Q corresponds to a narrower band of frequencies that will be phase-shifted).
For LowPass and HighPass filters, this control has no effect.
Scale
This is the attenuation or gain on the Input. The typical maximum for scale is 1, but it can be set as high
as 2 if necessary.
HighPass filters generally require lower Scale values than LowPass filters.
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