Show HN: Sirenfall, a civil defense siren synthesized in Web Audio https://ift.tt/nrPBLjy

Show HN: Sirenfall, a civil defense siren synthesized in Web Audio I built a cool browser scene, a shelter window over a dystopian city in the rain. Pull the breaker and a siren tower spins up. The wind-down is super unsettling and I love it. The siren is not a recording. Two port rings make a 5:6 dual tone, 515 and 618 Hz. The horn turns at 4 RPM and everything (loudness, brightness, doppler and stereo position) follows the horn angle you can see on the tower. Rain and thunder are the only recordings. Build it yourself, source is one HTML file and MIT: https://ift.tt/UPdruSi How it works: https://sirenfall.live/how-it-works Press F for fullscreen, S to save a picture. Landscape on phones. No cookies, no personal data, the only request besides audio is an anonymous page-count pixel. Appreciate any feedback and shoutout to the siren community! https://sirenfall.live/ September 4, 2026 at 02:14AM