Kurzweil KDFX, Manual

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Using the Algorithms
Filters
5-10
Spacing determines the starting pitch of the descending buzz and how fast it descends, by
setting the initial separation of impulses and the subsequent rate of increasing impulse
separation. The spacing between impulses is given in samples (20.8
m
s). At low values, the buzz
starts at high frequencies and drops slowly, while at high values the buzz starts at a lower pitch
and drops rapidly. Range is 0.0 to 40.0 samples, with a resolution of 0.2 sample.
Contour controls the overall shape of the reverb. When set to a high value, sounds passed
through the reverb start at a high level, and it slowly decays. As the control value is reduced, it
takes more time for the effect to build up before decaying. At a value of around 34%, the reverb
behaves like a reverse reverb, building up to a hit. When it is set to zero, the Algorithm acts like
a simple delay. Range is 0 to 100%.
Filters
There are four types of Resonant Filter Algorithms in KDFX. All of them have these parameters
in common:
Filter Type (or FiltType ) can be Lowpass, Highpass, Bandpass, or Notch (band-cut).
Resonance is the resonance of the Þlter, adjustable from 0 to 50 dB.
Resonant Filter
Frequency (or Freq ) is the Þxed resonant frequency of the Þlter. Its range is 16 to 8372 Hz.
Envelope Filter
Envelope Filter is a resonant Þlter whose center frequency can be made to vary according to the
level of the incoming signal.
Filter Type can be Lowpass, Highpass, Bandpass, or Notch (band-cut).
Min Freq is the minimum resonant frequency of the Þlter, that is, the Þlter frequency when the
input gain is below the triggering threshold. Its range is 16 to 8372 Hz.
Sweep determines how far the resonant frequency moves when the input level increases. At
positive levels it moves up in pitch, and at negative levels it moves down. The highest possible
resonant frequency is 8372 Hz, the lowest is 0 Hz. This parameterÕs range is -100% to +100%.
Resonance is the resonance of the Þlter, adjustable from 0 to 50 dB.
Atk Rate adjusts the upward slew of the attack portion of the envelope detector. Range is 0 to
300.0 dB/sec.
Rel Rate adjusts the downward slew of the release portion. Range is 0 to 300.0 dB/sec.
Smooth Rate slows down the envelope follower. If it is set to a lower rate than Atk Rate or Rel
Rate , it can dominate those parameters. Range is 0 to 300.0 dB/sec.
Triggered Filter
The Triggered Filter is a sweeping resonant Þlter that triggers when a certain input threshold is
reached, and then follows its
own envelope, consisting of an instantaneous attack and an
exponential release, rather than the envelope of the input signal.