Kurzweil K2661, Musician’S Reference Manual

Page: 254 / 500

10-172
KDFX Reference
KDFX Algorithm Specifications
911 Mono LaserVerb
912 LaserVerb Lite
913 LaserVerb
A bizarre reverb with a falling buzz
PAUs: 1 for Mono LaserVerb
2 for LaserVerb Lite
3 for LaserVerb
LaserVerb is a new kind of reverb sound that has to be heard to be believed! When it is fed an impulsive
sound such as a snare drum, LaserVerb plays the impulse back as a delayed train of closely spaced
impulses, and as time passes, the spacing between the impulses gets wider. The close spacing of the
impulses produces a discernable buzzy pitch which gets lower as the impulse spacing increases. The
following
fi gure is a simpli fi ed representation of the LaserVerb impulse response. (An impulse response of
a system is what you would see if you had an oscilloscope on the system output and you gave the system
an impulse or a spike for an input.)
Figure 10-89 Simplified Impulse Response of LaserVerb
With appropriate parameter settings this effect produces a decending buzz or whine somewhat like a
diving airplane or a siren being turned off. The descending buzz is most prominent when given an
impulsive input such as a drum hit. When used as a reverb, it tends to be highly metallic and has high
pitched tones at certain parameter settings. To get the decending buzz, start with about half a second of
delay, set the Contour parameter to a high value (near 1), and set the HF Damping to a low value (at or
near 0). The Contour parameter controls the overall shape of the LaserVerb impulse response. At high
values the response builds up very quickly decays slowly. As the Contour value is reduced, the decay
becomes shorter and the sound takes longer to build up. At a setting of zero, the response degenerates to a
simple delay.
The Spacing parameter controls the initial separation of impulses in the impulse response and the rate of
their subsequent separation. Low values result in a high initial pitch (impulses are more closely spaced)
and takes longer for the pitch to lower.
t = 0 time