Twin-Bell Alarm Clock

How it's made

Source

a spring-driven hammer alternates between two small metal bells at 17-27 hits/s. Each contact is a 0.3 ms attack and 1.6 ms filtered noise impulse; tiny rebounds add rattle.

Body

two fixed shell banks have inharmonic ratios 1, 1.48, 2.09, 2.76, 3.63 and 4.81. Fundamentals are 1.35-1.95 kHz; the second bell is 5-15 percent higher, not a tuned melody.

Decay

lower shell modes have 0.48-0.85 s T60, upper modes 0.12-0.32 s; close mode pairs beat. Fixed modes retain phase across hammer hits, accumulating a metallic ring rather than separate notes.

Layers

quiet 420/730 Hz case modes and 2-7 kHz contact chatter follow the same hammer motion.

Envelope

spring drive eases up over 60 ms and loses a little energy before stopping at 2.88 s. The bells then ring freely; a final safety fade ends at 4.02 s, with no room reverb.

Variation

seeded timing jitter, strike strength and shell mistuning; presets change bell size, hammer rate, shell damping, bell separation and loose mechanism level.

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