soundbox
A small studio for instruments made of wave equations. Compose strings, bars, membranes and a resonating body into a scene; the app writes the coupled PDEs as MATLAB, numbl compiles them to WebGPU compute shaders in your browser, and a microphone in the simulated air records what you then listen to. Play with a preset, build your own in the Build tab, or open the Lab to read (and edit) the equations and see the spectrum against where the partials should land.
tuning — free to move, even while it plays
shape — the instrument itself
Sizes recompile; body shape applies in place. Both change the geometry, so the next Fast render re-records the room. The full set of shape and placement controls is in the Build tab.
microphone
The measured spectrum of the recording (analyzed after Listen or Render clip), against each object's predicted partials: solid marks are the discrete scheme's own modes, dashed the continuous equations'. The gap between them is the numerical dispersion — on a coarse bar grid you can hear it.