Airlock Cycle

How it's made

Source

compressed air valved into a sealed chamber, then a bolt-driven hatch lock. Phase 1 is turbulent jet noise (pink + white) from a nozzle; phase 2 is a heavy bolt slamming home; phase 3 is a latch ring releasing with a servo motor spinning up and a last bleed of air.

Hiss

broadband noise through a band-pass whose centre rises from 1.2 kHz to 3.5-6 kHz as the chamber fills (smaller pressure ratio, faster jet), plus a duct resonance (≈ 260 Hz, Q 5) and an air-sheet band near 7 kHz. Level swells over about 0.4 s, holds, then falls off as pressure equalises.

Clunk

a 1 ms bolt impact into a steel frame. A sine drops from ≈ 120 Hz to ≈ 48 Hz in 90 ms (the frame body), low-passed noise adds the thud, and a few inharmonic metal modes (180-900 Hz, 0.3-0.6 s) ring.

Release

two latch clacks 70-110 ms apart (steel modes at 1.2-3.4 kHz, 0.1-0.25 s), a servo whine gliding from 180 Hz up to 520 Hz and back (saw through a band-pass, Q 6) and a short air bleed that fades out.

Envelope

hiss 0.15-2.5 s, clunk at 2.55 s, release 2.7-3.5 s, everything ends by about 3.9 s.

Variation

`rng` shifts the clunk time by a few ms, tunes modes by ±3 % and jitters clack strength; presets change hiss length, chamber size (pitch of body), clunk weight and the release character.

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