doux-copy/website/src/content/frequency-modulation.md

title, slug, group, order

title	slug	group	order
Frequency Modulation	frequency-modulation	synthesis	108

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Any source can be frequency modulated. Frequency modulation (FM) is a technique where the frequency of a carrier wave is varied by an audio signal. This creates complex timbres and can produce rich harmonics, from mellow timbres to harsh digital noise.

The frequency modulation index. FM multiplies the gain of the modulator, thus controls the amount of FM applied.

<CodeEditor code={/fm/2/note/60\n\n/fm/4/note/63\n\n/fm/2/note/67} rows={6} />

<CodeEditor code={/voice/0/fm/2/time/0\n\n/voice/0/fm/4/time/1} rows={4} />

The harmonic ratio of the frequency modulation. fmh*freq defines the modulation frequency. As a rule of thumb, numbers close to simple ratios sound more harmonic.

<CodeEditor code={/fm/2/fmh/2/} rows={2} />

<CodeEditor code={/fm/0.5/fmh/1.5/} rows={2} />

<CodeEditor code={/fm/0.25/fmh/3/} rows={2} />

FM modulator waveform shape. Options: sine, tri, saw, square, sh (sample-and-hold). Different shapes create different harmonic spectra.

<CodeEditor code={/fm/2/fmshape/saw} rows={2} />

Envelope amount of frequency envelope.

<CodeEditor code={/fm/4/fmenv/4/fmd/0.25} rows={2} />

The duration (seconds) of the fm envelope's attack phase.

<CodeEditor code={/fm/4/fma/0.25} rows={2} />

The duration (seconds) of the fm envelope's decay phase.

<CodeEditor code={/fm/4/fmd/0.25} rows={2} />

The sustain level of the fm envelope.

<CodeEditor code={/fm/4/fmd/0.25/fms/.5} rows={2} />

The duration (seconds) of the fm envelope's release phase.

<CodeEditor code={/fm/4/fmr/1/release/1/duration/.1} rows={2} />