Arnov Sharma's build, covered by Hackaday, is a small piece of responsive wall art: a MAX9814 microphone amplifier feeding a Pi Pico 2, which drives a 64 by 32 HUB75 RGB matrix with a scope-style trace of the incoming sound. The automatic gain control is the detail worth noting, since it keeps quiet and loud rooms both usable without clipping.
Be clear about what it is. This is a waveform display, not a cymatic pattern — the geometry comes from the code, not from a resonating surface. It belongs in this feed because the hardware path is the one many of us already use for LED ring arrays, and because it is a tidy reference build for enclosure, panel choice and mic conditioning.
The comments underneath are worth a skim for the usual disagreement about HUB75 panel reliability, which is a real consideration if a piece is going to run for months.