Shrinking consumer electronics to their practical limits is a recurring theme in the DIY hardware space, and a recent project from the YouTube channel Gadget Industry takes that idea to an impressive extreme. The build centers on a Bluetooth speaker so small it undercuts the size of a single AirPods earbud, yet still manages to function like a conventional portable speaker. At the core of the design is a modest 3 W Bluetooth audio amplifier, paired with a micro speaker measuring just 18 × 14 mm. Off-the-shelf modules are typically far too bulky for a form factor this small, so the builder dismantles them completely, removing unnecessary PCB sections and repositioning components to minimise footprint. The original PCB antenna is sacrificed, and the remaining parts are stacked and hand-wired into a dense but deliberate layout in dead bug style.
Power management follows the same philosophy. A TP4056-based charging circuit is stripped down and rebuilt to fit the constrained volume, then connected to a 60 mAh LiPo battery that supplies just enough energy for short playback sessions. A tiny slide switch completes the electrical design, providing basic power control without adding complexity. From an embedded systems perspective, the circuit itself is straightforward. Instead of relying on a 3D-printed enclosure, the project uses a hand-crafted epoxy resin case. Thin resin sheets are cast, sanded to a frosted finish, and cut into panels that form a small cube around the electronics. The result is a semi-transparent housing that exposes the project’s DIY nature while remaining structurally sound. It is an unconventional enclosure method, but one that suits the scale of the build and avoids the tolerances and wall thickness limitations common in desktop 3D printing. In testing, the speaker behaves much like any other Bluetooth audio device, pairing with a phone and playing music without fuss. Audio output is predictably limited by size and battery capacity.
