Kurzweil KDFX, Manual

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Using the Algorithms
SRS¨ (Sound Retrieval System)
5-15
Ring Modulation
Ring modulation multiplies two signals (the ÒcarrierÓ and the ÒmodulatorÓ) together to
produce unusual, often non-harmonic, overtones. The Ring Modulator Algorithm in KDFX has
two modes: Ò
L*R Ó in which two mono signals are modulated together; and Ò Osc Ó, in which the
input is stereo, and it is modulated with the sum of Þve waveforms that are generated from
oscillators within the Algorithm itself. Four of these oscillators are sine waves, while one
(Oscillator 1) offers a selection of waveforms.
Wet/Dry. When the Algorithm is in ÒL*RÓ mode, this controls how much of the left signal only
is passed dry (the right signal isnÕt passed dry at all).
Mod Mode selects between the two modes.
Osc1 Lvl is the level of Oscillator 1, from 0 to 100%.
Osc1 Freq is the frequency of Oscillator 1, from 16 to 25088 Hz.
Osc1 Shape is the waveshape of Oscillator 1, selectable from Sine, Saw+, Saw-, Pulse, and Tri.
Osc1PlsWid (Pulse Width). When Osc1 Shape is set to Pulse, this sets the pulse width as a
percentage of the waveform period. When the width is set to 50%, the result is a square wave.
This parameter has no effect if other waveform types are chosen. Range is 0 to 100%.
Osc1Smooth smooths (removes the higher harmonics from) the Saw+, Saw-, and Pulse
waveforms. A Sawtooth wave becomes more like a triangle wave, and a Pulse wave becomes
more like a sine wave. Range is 0 to 100%.
The other four oscillators, Sine2 through Sine5 , each have Lvl and Freq controls.
SRS
¨
(Sound Retrieval System)
SRS, which is used under license from SRS Labs, Inc., is a single-ended processing system that
produces a fully immersive, three-dimensional sound image from any audio sourceÑmono,
stereo, surround sound, or encoded with any other audio enhancement technologyÑwith two
or more standard speakers.
The four parameters control the ambience of the image, and may have different optimal
settings depending on the amount of stereo content in the input signal. To match the optimal
settings speciÞed by SRS Labs, the bass and treble gains should be set to 0 dB. This Algorithm
will have no effect on mono signals. All ranges are -79.0 to 24.0 dB.
Center varies the amount of Òcenter channelÓ in the output. It has an ÒOffÓ position.
Space controls the width of the image. It, too, has an ÒOffÓ position.
Bass Gain and Treb Gain set the amount of ambience added to the low and high frequencies,
respectively, in the signal. Setting both of these to 0 dB gives a best match to the optimizations
of SRS Labs.