Subtractive Synthesis

Build sounds from scratch. Choose waveforms, shape them with filters, sculpt dynamics with envelopes.

Oscillators

Every subtractive synth starts with an oscillator. It generates a raw waveform — the harmonic content you will later shape with filters. Choose a waveform below and press play to hear how they differ.

How the shape gets made

The harmonics inside it

H1 is the note you played. H2–H8 are the harmonics stacked above it — the part that makes a sawtooth sound different from a sine.

Each circle is one harmonic, turning at its own speed. Stack them end to end and the last point draws the wave. Build a sound this way on the additive explorer, where you set every harmonic yourself.

This bypasses the envelope — use Trigger Note in Section 3 to hear the full ADSR shape.

Octave

Select a waveform, then press play to hear it

Check Your Understanding— Which waveform would you start with for subtractive synthesis?

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Understanding waveforms

Sine Wave

Contains only the fundamental frequency — no harmonics. Produces a pure, smooth tone. This is the simplest waveform.

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Triangle Wave

Contains odd harmonics only (1st, 3rd, 5th…), each falling as 1/n² — much faster than a square wave. This is why it sounds warmer and softer.

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Sawtooth Wave

Contains ALL harmonics (odd and even) at decreasing amplitude. Sounds bright and buzzy — the most common starting point for subtractive synthesis.

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Square Wave

Contains only odd harmonics (1/n amplitude law), each louder than the corresponding triangle harmonic (which fall as 1/n²). Sounds hollow and woody — often used for bass and pad sounds.

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Exam tip: A sawtooth is the go-to starting waveform for subtractive synthesis because it has the richest harmonic content to filter.