ADBDR's two decay slopes model a piano better than ADSR's flat sustain

ADSR’s Sustain segment holds a constant level while a key is held — but a real piano note keeps decaying the whole time it sounds, so a flat sustain can feel artificial for piano-like patches. The ADBDR envelope (Attack-Decay1-Break-Decay2-Release) replaces the flat sustain with two consecutive decay slopes: the sound falls quickly at first (Decay1), reaches a Break point, then continues to fall slowly (Decay2). The Break control sets the level at which Decay1 hands off to Decay2. This continuously-falling shape approximates a held piano note far better than a plateau. The broader lesson: choose an envelope’s segment structure to match the amplitude behaviour of the sound you are imitating.

Examples

Use ADBDR for piano/plucked patches where a held note should keep fading. Use ADSR (flat sustain) for organs and pads that hold steady. AD (no sustain) suits percussive one-shots.

Assessment

Explain why ADSR is a poor choice for a piano-like patch held for 5 seconds, and how ADBDR’s Break/Decay2 fixes it.