Jamie Matthews Turns Junk $0.50 Bluetooth Earbuds Into Swish, 3D-Printed Multi-Room Audio Adapters

Maker Jamie Matthews has found a low-cost solution for true wireless stereo audio, by pulling apart cheap Bluetooth headphones and turning them into swish 3D-printed audio adapters — for under $10.

"For a while now I've been looking for some Bluetooth adapters that I could use for multi-room/wireless stereo throughout my home," Matthews explains. "Unfortunately systems like the Sonos are very expensive, plus I want to use the speakers I already have and love. So I went on a search for an alternative."

Dismissing off-the-shelf portable speakers, Matthews turned to ultra-low-cost "I12" in-ear true wireless stereo earbuds — purchasing a lot of 10 sets, complete with charging cases, for $0.50 a pair as spares-or-repair. "These tend to stop working because of the charging case design," Matthews explains. "This causes the buds not charge any more, and leads to a load of these being thrown away… good for us tinkerers though!"

Matthews wasn't looking for earbuds, though, and so set about adapting the devices for multi-room audio use. Stripping them apart and removing the core circuitry, Matthews designed a 3D-printed housing which takes the hardware from each earbud and either an original or optionally expanded-capacity battery and converts it to offer an analog 3.5mm-jack audio output.

The adapters, ready for connection to Matthews' existing powered speakers, nestle in a 3D-printed dock when not in use — cleverly making use of pogo-pin connectors salvaged from the original charging case and a cut-down USB cable to automatically charge each adapter when docked.

Matthews has published a full guide, with 3D print files, on Instructables, saying the adapters can achieve multi-speaker audio with a 10 meter (around 33') range when connected to a Bluetooth 5.2 device.