Security Alert

How it's made

Source

an electronic alarm pulse, a pair of bright reed-like tones a tritone apart (ratio 1.414) sounded together. The interval has no stable consonance, which reads as tension; the pair is the whole message.

Body

each tone is a band-limited saw (rich in harmonics) plus a sine at the fundamental, run through a low-pass that sweeps from about 4x to 1.5x the note over the pulse, so the attack is sharp and the tail mellows. A short inharmonic partial (2.76x) adds a metallic ping on the strike, a 20 ms noise tick adds bite.

Envelope

3 ms attack (click-free), then an exponential-like fall of about 0.3 s; the pulse repeats twice at 0.5 s with the second pulse slightly softer, and the whole sound ends in a short fade.

Variation

`rng` detunes each tone by a few cents so the beating of the two saws is not frozen; presets change pitch, interval (tritone, minor second, minor ninth), pulse count, spacing, stagger and brightness.

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