Thunder Crack

How it's made

Source

impulsive expansion of a nearby lightning channel; a 0.6 ms onset excites a 95 ms broadband noise crack, followed by 2-7 weaker channel arrivals spaced irregularly over 20-280 ms.

Body

nonperiodic air-pressure noise, high-passed at 32 Hz; the explosive body darkens from 1.8 kHz to 180 Hz in 0.9 s. No pitched oscillator or narrow resonator is used.

Envelope

the direct crack decays rapidly; distributed channel segments swell at 0.12, 0.5 and 1.1 s, with overlapping 0.8-2.4 s decays. A smooth final taper ends the default at about 4 s.

Spectrum

the direct wave reaches 5-11 kHz; rolling pressure spans 40-650 Hz and loses high frequencies sooner than bass, modelling the greater propagation distance of the receding channel segments.

Variation

seeded noise, branch timing, gain and pan vary independently. Sharpness controls the shock spectrum, branches the fractured onset, rumble the tail weight, and length the channel arrival spread.

Presets

exposed sharp strike, heavy low thunder, a fractured multi-branch crack, and a compact dry hit. Stereo spread affects late channel arrivals; the initial pressure wave stays centred.

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