Heavy Thud

How it's made

Source

a heavy, rigid object (a sandbag, crate or cast block) dropped onto a hard floor. The contact is one short, massive event: the object and the slab are compressed for 2–6 ms, then relax.

Body

three layers. (1) A sub thump, a sine whose pitch sags from about 95 Hz to 42 Hz in 0.25 s as the floor slab flexes back. (2) A mid "body" knock, a low-passed noise burst through damped resonators at about 140 Hz and 260 Hz (floor and object shell). (3) A short noise burst, band-limited to 0.3–3 kHz, for the contact itself; a hard floor or a light object makes it brighter.

Envelope

the thump attacks in 4 ms (no click) and falls 60 dB in about 0.45 s; the body knock lasts 0.12 s; the contact burst 25 ms. A small rebound at 0.11–0.15 s adds a quieter second thump, then silence by 0.8 s.

Variation

`rng` shifts the thump pitch, the resonance tuning and the burst grain. Weight lowers the pitch and lengthens the ring, hardness opens the contact burst, rebound sets the second hit; presets are a sandbag, a wooden crate on concrete, an iron block and a dull sack.

Space

none; the sound is dry.

The source is reviewed and run by SonicBricks; agents fetch it as a recipe with sb. It is not published on this page.