Shaping sound

These operators change the level, the spectrum or the shape of a sound over time. They work on any Sound.

Level and mixing

* multiplies a sound by a level, and + mixes two sounds together.

// Two saws a fifth apart, each at a third of full level.
(Saw(110) * 0.3) + (Saw(165) * 0.3)

// Mixing an offset is also allowed: a constant added to a sound shifts its DC level.
(Sine(110) + 0.1) * 0.4

Gain(x) is the same as * x, and reads better in a chain:

Saw(110).Gain(0.4)

Two sounds multiply sample by sample, which is ring modulation. The result has sidebands at the sum and difference of the two frequencies, a metallic sound rather than a volume change.

// Ring modulation: a 220 Hz tone times a 33 Hz tone.
Sine(220) * Sine(33) * 0.6

Envelopes

Adsr(attack, decay, sustain, release, hold) shapes a sound's level over time. hold sets how long the note stays open when no note is playing. Times are in seconds.

// A plucky saw: fast attack, quick decay to half level, then held.
Saw(110).LowPass(900, q: 2).Adsr(0.01, 0.2, 0.6, 0.8, hold: 0.5) * 0.4

Filters

Each filter takes a cutoff (or centre frequency) and an optional q, which sets the resonance. A higher q gives a sharper peak.

Filter	Keeps
LowPass(cutoff, q)	Everything below the cutoff.
HighPass(cutoff, q)	Everything above the cutoff.
BandPass(center, q)	A band around the centre.
Notch(center, q)	Everything except a band around the centre.

// Noise through a narrow band: a whistle-like tone at 1.2 kHz.
Noise().BandPass(1200, q: 12) * 0.5

Tone controls

Peak, LowShelf and HighShelf add a boost or cut at one frequency. Equalize is a three-band tone control in dB.

// A peaking boost of 9 dB around 1 kHz.
Saw(110).Peak(1000, q: 3, gainDb: 9) * 0.3

// Warmer lows, scooped mids, bright top.
(Saw(110) * 0.3).Equalize(lowDb: 3, midDb: -4, highDb: 2)

Keeping levels safe

Limit(ceiling, release) stops peaks above the ceiling. Put it last in a chain that mixes several sounds.

// Two loud saws, mixed and kept under the ceiling.
(Saw(110) + Saw(111.5)).Limit() * 0.8

Range(min, max) also maps a sound's -1 to 1 into a new span, which is how controls and LFOs are scaled. See Parameters.