Gong ageng
The deep gong of the Javanese gamelan, reimagined as an analog instrument: Rhodes-style tine and tone bar mechanics instead of four feet of bronze.
Just out of college I lived in a house with a four-foot bronze gong, its center boss filled with pitch. Standing in front of it when it was struck was close to a religious experience: a fundamental you feel more than hear, and a slow wa-wa-wa beat rolling through the room for what seemed like forever.
The gong ageng is the largest gong in the Javanese gamelan, and it marks the end of each musical cycle. A good one is huge, expensive and hard to find. This project is an attempt to get that sound, and its physical sound pressure, without the bronze.
The target sound
I settled the target by ear, synthesizing it in Python and playing it through a 10-inch subwoofer: a clean fundamental around 33 to 36 Hz, a slow beating (the ombak) at about 1 Hz, and a very long tail that drops quickly just after the strike. The moment of truth was a recording of a real gong ageng, slowed to a 36 Hz fundamental with its ombak re-timed to 1 Hz. That was it.
The idea
Rather than play a sample through a big speaker, build an analog generator. A Fender Rhodes gets its tone from a tine coupled to a heavy tone bar: a tuning fork, really. Scaled up and tuned low, the same mechanics might make a sustained, beating low tone with real presence. Further out: a large, light disc driven around its edge by a magnet-and-coil motor and hung from the wall, so it moves air the way the real gong does.
Status
Speculative. The Open Kalimba comes first; its small test bars will show whether the tine-and-tone-bar approach scales down to 36 Hz.