Kurzweil K2661, Справочник музыканта

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10-72
KDFX Reference
KDFX Algorithm Specifications
By adding the phaser output to the dry input using, for example, a Wet/Dry parameter, you can produced
peaks and notches in the frequency response. At frequencies where the phaser is “in phase” with the dry
signal, the signal level doubles (or there is a 6 dB level increase approximately). At frequencies where the
phaser and dry signals are “out of phase,” the two signals cancel each other out and there is a notch in the
frequency response. You can get a complete notch when Wet/Dry is set to
50% . If subtraction is used
instead of addition by setting Wet/Dry to -50% , then the notches become peaks and the peaks become
notches.
As mentioned earlier, allpass phasers leave the phaser motion up to you, so they have no built in LFOs. To
get phaser motion, you have to change the
fi lter center frequencies (left and right channels) yourself. The
best way to do this is with an FXMod.
When feedback is used, it can greatly exaggerate the peaks and notches, producing a much more resonant
sound. Cross-coupling (XCouple) the feedback between the left an right channels increases the complexity
of the frequency response.
In the fi gure above, you’ll notice that the spacing of the notches and peaks are not harmonically related.
When a lot of feedback is used, the non-harmonic structure produces very bell-like tones, particularly with
XCouple set to
100%. (Don’t modulate the frequencies to get this effect.) Try experiments using different
allpass orders for the feedback, different frequency arrangements, changing the sign (+/-) of the feedback
(Fdbk Level) parameter, and different input sources (drums are a good starting point).
Parameters:
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Wet/Dry The amount of phaser (wet) signal relative to unaffected (dry) signal as a percent.
Out Gain The output gain in decibels (dB) to be applied to the combined wet and dry signals.
Fdbk Level The phaser output can be added back to its input to increase the phaser resonance.
Negative values polarity invert the feedback signal.
XCouple Determines how much of the right feedback signal to feed into the left input channel and
how much left feedback to feed into the right input channel. When increasing cross-
coupling, the amount of feedback from one channel into its own input is reduced, so that
at
100% the left feeds back entirely to the right channel and vice versa. [Stereo versions
only]
CenterFreq The nominal center frequency of the phaser fi lter. The frequency LFO modulates the
phaser fi lter centered at this frequency. There are separate left and right controls in the
stereo version.
FB APNotch The number of notches the allpass fi lter can produce when summed with a dry signal.
Used in the feedback loop. Higher values produce more resonant peaks, for a more
complex resonant structure.
OutAPNotch The number of notches the allpass fi lter can produce when summed with a dry signal.
Used on the algorithm output. Higher values produce a steeper, longer phase response
resulting in more peaks and notches when combined with the dry signal.
Wet/Dry -100 to 100%wet Out Gain Off, -79.0 to 24.0 dB
Fdbk Level -100 to 100% XCouple 0 to 100%
LCenterFreq 8 to 25088 Hz RCenterFreq 8 to 25088 Hz
FB APNotch 3 to 6 or 7 to 10 OutAPNotch 3 to 6 or 7 to 10