Distant Explosion

How it's made

Source

a large detonation several kilometres away. The sharp crack and all content above ~400 Hz are absorbed by air and terrain; what arrives is the blast's pressure wave: a soft 30–60 ms swell, not a click.

Body

a sub-bass thump (sine gliding 75 → 32 Hz as the fireball's pressure relaxes) over a brown-noise rumble low-passed from ~280 Hz down to ~55 Hz, so the spectrum darkens as the sound decays.

Echoes

the wave bounces off hills and tree lines; 2–8 delayed, ever softer and darker low-passed noise swells (0.25–2.4 s later, 55–170 Hz) roll after the main boom and are panned apart for width.

Envelope

~40 ms swell, ~0.6 s heavy body, then a slow 2–3 s fade; the echoes make the tail undulate.

Variation

`rng` jitters echo timing, strength, pitch and pan; `distance` sets the low-pass ceiling and how late and how diffuse the echoes are; `weight` balances sub-bass against rumble.

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