Bullet Ricochet

How it's made

Source

a small projectile glances off a metal plate. The contact is a sub-2 ms broadband crack, followed by the plate ringing and by the deflected projectile leaving with a spinning, turbulent whistle.

Body

the plate rings in a few inharmonic metal-bar modes (≈ 1 : 2.76 : 5.4 : 8.9, 0.15–0.5 s) that give the "ping"; the flight whistle is a narrow tone plus a band-passed turbulence layer riding on the same pitch.

Envelope

the crack is over in 3 ms; the ping decays exponentially; the whistle starts just after contact, falls in pitch (doppler of a receding source, ≈ 3 kHz → 0.9 kHz) while its level and brightness fade over most of the 0.9 s (distance loss: air absorption closes the high end first).

Layers

crack + plate ping + whistle tone + whistle air, summed dry; the ping is the loudest early, the whistle dominates after 0.15 s.

Variation

`rng` detunes the plate modes and the whistle start pitch by a few percent; parameters set the plate size, hardness of contact, whistle pitch and how fast the projectile recedes.

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