Noise & Percussion

Kick, snare, and hi-hat synthesised from scratch using oscillators, white noise, and fast ADSR envelopes — no samples, no files.

Hit the drums

Click a pad to trigger the sound. Each drum is built from the signal chain shown in its card below.

Signal chains

Kick

Sine oscillator with a fast pitch drop (80 Hz → 40 Hz in ~0.5 s) and a volume envelope that punches then quickly fades. The pitch drop is the characteristic "thud".

Start pitch 80 Hz

Punch (ms) 60 ms

Decay (ms) 400 ms

Snare

Mix of a mid-pitched oscillator (crack) and filtered white noise (rattle). The noise is high-passed to remove low-frequency mud. A fast decay gives the snappiness.

Tone pitch 200 Hz

Noise mix 70 %

Decay (ms) 150 ms

Hi-hat

Six square-wave oscillators at metallic (inharmonic) frequency ratios, summed and high-pass filtered to create that characteristic bright "tsss". Open/closed is just decay length.

Tone 4 kHz

Decay (ms) 60 ms

Oscilloscope

The waveform shown below updates whenever you trigger a drum. Notice the sine pitch-drop of the kick, the spiky transient of the snare, and the dense harmonic content of the hi-hat.

How it works

White noise contains all frequencies in equal measure. It's generated by producing random amplitude values at the audio sample rate — the same randomness that makes it sound like static or rushing air. A short looping buffer is all you need.

Pitch envelopes work the same way as volume envelopes — exponential ramps applied to frequency instead of amplitude. Dropping pitch and volume simultaneously is what gives the kick its physical "thud" quality.

Inharmonic ratios for the hi-hat: the six frequency ratios are approximate multiples of the fundamental — 1.0, 1.483, 1.932, 2.546, 3.175, 4.023. These ratios appear in metallic percussive instruments and produce the characteristic clangorous timbre (similar to FM synthesis with non-integer ratios).