Granular Synthesis - "Rain"
How it works:
This sound uses the Parabolic Envelope which generates a very short
arc. When the envelope is triggered, it latches a random value for
a sine oscillator using a LatchUnit. The sine wave is multiplied
by the parabolic envelope to generate a very short burst of a sinewave
similar to a wavelet. This example instantiates 8 grain circuits.
The sound on the left channel is the original grains. The sound on
the right channel is the output of a MultiTapDelay which is used to make
it sound like there are more grains playing at once. Another granular synthesis
technique is to multiply the envelope by a sampled sound or a complex wavetable.
- Probability - controls the likelyhood of triggering a parabolic envelope
on any given sample. Triggers are generated by a PoissonTrigger
circuit that outputs a trigger whenever a white noise source exceeds
a threshold determined by "Probability".
-
Frequency - determines the center frequency of the sine wave oscillators.
-
Spread - determines the maximum random deviation of the sine wave frequency.
-
GrainSpeed - determines how quickly the ParabolicEnvelope moves from zero
to maximum amplitude then back to zero. If a ParabolicEnvelope were
retriggered continuously then it would generate this many arcs per second.
-
Feedback - determines how much of the delayed sound is mixed back into
the delay line. This determines how long it takes for the sound to decay.
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