Most desktop speakers give you sound and nothing to watch. DAKD Jung tackled that gap with a DIY Bluetooth speaker that carries an audio-reactive ferrofluid display cell: black fluid in a round glass container that spikes, splits apart and bounces along with the frequencies of the track, all backed by warm white LED light. A physical visualizer built right into the speaker, rather than a screen, is a genuinely appealing idea.
The electronics started on the workbench, with an Arduino on a breadboard, an 8x8 LED matrix and an MSGEQ7 spectrum analyzer module. An electromagnet pulses the ferrofluid in step with the audio. For the sound itself there are dual full-range drivers in a sealed rectangular enclosure with a passive radiator. The cabinet was modeled in Autodesk Fusion 360 with upward-firing speaker ports, then 3D printed. The first white print came out flawed, so it was sanded, filled and spray-painted. Drivers, passive radiator, bracket, LEDs and electromagnet were all assembled into the enclosure.
Two details stand out to me. The glass cell received a chemical surface treatment so the ferrofluid would not adhere to it, which seems like a smart move if the spikes are meant to form and let go cleanly. And the fluid was reprocessed from Ferrotec EFH-1 ferrofluid rather than used as-is.
The finished piece looks tidy too, a matte white enclosure with an angled front face, horizontal vents along the top and a recessed, illuminated circular window for the fluid. One question stays open for now: what a copy of this build would actually cost.
Project by DAKD Jung (DAKD JUNG). Watch it on their YouTube channel: