Portable Bluetooth speaker

• Amplifiers: 2x10W AB class
• Battery: 37 Wh 3-cell Li-Ion
• Built-in analog equalizer
• Bluetooth or 3.5 mm jack
• Charging current: 1.5 A max (manually configurable or automatic MPPT)
• Charging power: 15 W max
• USB output (up to 2 A)
• Requisite over-temperature and overload protections including error reporting

Almost everything is custom designed (except the Bluetooth module and the two power converters visible here, but those were modified to be controllable by the microcontroller). The enclosure is made out of layers of laser-cut plywood, the back is 3 mm aluminum for structural and cooling purposes. It’s not the most efficient speaker in the world because it uses AB amplifiers. Pretty much all portable speakers use class D, which is way more efficient but has higher distortion.

Participated in the electronics competition in Rožnov pod Radhoštěm. Dokumentace reproduktor 2019.