Waveform Generator — Custom Waves
Design custom waveforms online with Fourier additive synthesis and live harmonic controls plus live waveform view. For timbre study. Free in your browser.
Protect your hearing. Start at a low volume. Never raise the volume to make a tone audible. Levels are shown in dBFS, relative to full scale — not SPL.
How it works
Audio waveforms are synthesized using Fourier additive synthesis via Web Audio PeriodicWave tables. Wave cycles are rendered dynamically to an HTML5 canvas alongside an oscilloscope time-domain analyzer. All DSP executes locally in your browser.
Synthesize custom musical timbres and acoustic wave shapes using 16-harmonic additive synthesis. Hear immediately how individual overtones reshape both the sonic character and the geometric profile of the wave.
The Harmonic Series & Timbre
Every musical note generated by vibrating strings, vocal cords, or acoustic air columns produces a fundamental pitch accompanied by a ladder of upper harmonics:
| Harmonic | Multiple | Frequency at 220 Hz | Musical Interval |
|---|---|---|---|
| 1st (f₁) | 1× | 220 Hz | Fundamental (Unison) |
| 2nd (f₂) | 2× | 440 Hz | 1 Octave |
| 3rd (f₃) | 3× | 660 Hz | 1 Octave + Perfect 5th |
| 4th (f₄) | 4× | 880 Hz | 2 Octaves |
| 5th (f₅) | 5× | 1,100 Hz | 2 Octaves + Major 3rd |
| 6th (f₆) | 6× | 1,320 Hz | 2 Octaves + Perfect 5th |
| 7th (f₇) | 7× | 1,540 Hz | 2 Octaves + Harmonic Minor 7th |
| 8th (f₈) | 8× | 1,760 Hz | 3 Octaves |
Classic Waveform Profiles
- Pure Sine: Single harmonic at $n=1$. Smooth, round, and devoid of overtones.
- Square Wave: Odd harmonics only ($1, 3, 5, 7\dots$), with amplitudes proportional to $1/n$. Sounds hollow, woody, and retro.
- Sawtooth Wave: All harmonics ($1, 2, 3, 4, 5\dots$), with amplitudes proportional to $1/n$. Sharp, bright, and cutting—the foundation of analog synthesizer brass and leads.
- Triangle Wave: Odd harmonics only ($1, 3, 5, 7\dots$), but decaying rapidly at $1/n^2$. Mellow and flute-like with subtle warmth.
- Tonewheel Organ: Emulates classic Hammond drawbars where specific intervals (sub-octave, 5th, octave) are layered to produce lush acoustic chords.
Frequently asked questions
What is Fourier additive synthesis?
Fourier's theorem proves that any periodic waveform can be deconstructed into a sum of simple sinusoidal waves (sine and cosine), each oscillating at integer multiples (harmonics) of a fundamental frequency. By adjusting the amplitude of each harmonic partial, you can sculpt any timbre from scratch.
What makes a square wave sound buzzy compared to a sine wave?
A pure sine wave contains only a single frequency—the fundamental (1f). A square wave contains the fundamental plus every odd harmonic (3f, 5f, 7f, 9f...) decaying inversely with frequency (1/n). Those high-frequency odd harmonics create the sharp, buzzy edge that characterizes square waves.
Why do instrument timbres differ if they play the exact same pitch?
When a violin, trumpet, and flute all play Middle C (261.63 Hz), they share the exact same fundamental pitch. What makes them sound distinct is their harmonic spectrum: the relative volume balance of the 2nd, 3rd, 4th, and higher overtones, along with transient attack times.
How does the Web Audio PeriodicWave API work?
The browser's Web Audio API compiles the array of real and imaginary Fourier coefficients into an internal band-limited wavetable. This ensures that even when you play high pitches with dozens of harmonics, the audio does not suffer from digital aliasing distortion.