Kurzweil K2661, Справочник музыканта

Страница: 247 / 500

KDFX Reference
KDFX Algorithm Specifications
10-165
908 Pitcher
Creates pitch from pitched or non-pitched signal
PAUs: 1
This algorithm applies a fi lter which has a series of peaks in the frequency response to the input signal.
The peaks may be adjusted so that their frequencies are all multiples of a selectable frequency, all the way
up to 24 kHz. When applied to a sound with a noise-like spectrum (white noise, with a
fl at spectrum, or
cymbals, with a very dense spectrum of many individual components), an output is produced which
sounds very pitched, since most of its spectral energy ends up concentrated around multiples of a
fundamental frequency.
If the original signal has no sign fi cant components at the desired pitch or harmonics, the output level
remains low. The left and right inputs are processed independently with common controls of pitch and
weighting. Applying Pitcher to sounds such as a single sawtooth wave will tend to not produce much
output, unless the sawtooth frequency and the Pitcher frequency match or are harmonically related,
because otherwise the peaks in the input spectrum won't line up with the peaks in the Pitcher
fi lter. If
there are enough peaks in the input spectrum (obtained by using sounds with noise components, or
combining lots of different simple sounds, especially low pitched ones, or severly distorting a simple
sound) then Pitcher can do a good job of imposing its pitch on the sound.
The four weight parameters named “Odd Wts”, “Pair Wts”, “Quartr Wts” and “Half Wts” control the
exact shape of the frequency response of Pitcher. An exact description of what each one does is,
unfortunately, impossible, since there is a great deal of interaction between them. Here are some examples
with a Pitch setting of 1 Khz, which is close to a value of C6. Weight settings are listed in brackets
following this format: [Odd, Pair, Quartr, Half].
Figure 10-78 [100, 100, 100, 100]
In Figure 10-78, all peaks are exact multiples of the fundamental frequency set by the Pitch parameter.
This setting gives the most "pitchiness" to the output.
Figure 10-79 [-100, 100, 100, 100]
Khz
dB
dB
Khz