Steel sheet gong: how the parameters shape the sound
Each section varies one property of the simulated sheet or of the excitation while everything else stays at the simulator defaults: a 12 by 18 inch, 22 gauge (0.79 mm) stainless steel sheet hanging in portrait orientation with a 3 mm bow across its width, heard 1 m in front of its center, recorded for 4 s. The clips are computed on a 4 mm grid (the interactive app defaults to 8 mm for speed; the 'Open in simulator' links carry the 4 mm setting, so they reproduce the clip exactly but run slower). Click a player to hear a clip. Within a section the clips share one playback gain, so the loudness differences you hear are the ones the model predicts; between sections the gain differs. The numbers under each clip are the peak pressure and sound pressure level at the listener, the RMS pressure over the clip, the spectral centroid of the sound between 0.2 and 1.2 s (a measure of brightness), and fitted 60 dB decay times of a low and a high band.
A wooden stick tip (30 g effective mass) strikes the sheet at 70 percent of its width and 35 percent of its height. Speed sets both the loudness and the character: the contact force grows with speed, the contact shortens, and more energy reaches the high modes. The sound grows brighter as well as louder.
All clips in this section share the same playback gain (-10 dB relative to 1 Pa = 0 dBFS), so their loudness differences are real. Spectrograms: 0 to 5 kHz over the clip, 80 dB range, shared color scale.
The same speed with a lighter or heavier stick. A heavier stick carries more momentum, stays in contact longer, and pushes the sheet further, which favours the low modes; a light stick gives a short, bright tap.
All clips in this section share the same playback gain (-4 dB relative to 1 Pa = 0 dBFS), so their loudness differences are real. Spectrograms: 0 to 5 kHz over the clip, 80 dB range, shared color scale.
