ADSR Envelope Sculptor 2D — Drag-Node Sound Design Lab

Trigger

Envelope Shape

Attack 30 ms

Decay 180 ms

Sustain level 55%

Release 400 ms

Sound-Design Presets

Live Readout

Envelope level

Time since trigger

0.00 s

Phase

Idle

How it works

Sound designers rarely shape a raw waveform directly — they shape its loudness envelope: the curve that multiplies a sound's amplitude over time. A four-stage Attack–Decay–Sustain–Release (ADSR) envelope is the standard model, piecewise linear in time t since the trigger (A, D, R in seconds, S in [0,1]):

0 ≤ t < A:        L(t) = t / A                        (Attack: silence → peak)
A ≤ t < A+D:      L(t) = 1 − (1−S)·(t−A) / D            (Decay: peak → sustain)
held, t ≥ A+D:    L(t) = S                              (Sustain: held level)
after release, τ: L(t) = S · (1 − τ / R)                (Release: fade to silence)

The article's core claims about perception map directly onto these four numbers:

Fast Attack (≈10–40 ms) reproduces a sharp transient — the "sudden, sharp sound" that grabs attention immediately, like a gunshot or door slam.
Slow Attack (hundreds of ms – seconds) reads as a gradual swell — the "prolonged, subtle effect" the article says builds unease or tension, like a horror drone rising under a scene.
Sustain level sets how loud the effect sits once it has settled — high sustain reads as a continuous ambient layer, low sustain reads as a transient hit that has already mostly decayed.
Release controls how a sound trails off after the trigger is let go — a long release leaves a tail (reverb-like), a short one cuts cleanly.

Controls: press and hold the trigger button (or press Space) to fire the envelope — it runs Attack → Decay → Sustain while held, then Release the instant you let go. On the curve panel you can also drag the four coloured nodes directly to reshape Attack, Decay/Sustain and Release without touching a slider. The lower panel shows a pulsing impact disc that scales and glows with L(t), plus a scrolling bar history of recent loudness, colour-coded by phase.

Attack Decay Sustain Release

Hold the button (or Space) to trigger — drag the curve's nodes to reshape it