True Wireless Speaker Pair

Jokes on Matt, he wasted his time when ready made true wireless stereo amp boards exist.

I designed and 3D printed an enclosure to put on the back of these lovely speakers (Philips FWB-MCM760). It contains a battery, power management, boost converter, voltage indicator LCD, and amplifier.

I also hacked the BT module to add an antenna for better range since the PCB antenna is garbage.

I made a custom PCB to connect the power management components. It disconnects the buck converter from the BMS to prevent it from trickle draining the system while not charging. Charges with regular 19V barrel plug supplies.

Also of note is that I replaced an SMD resistor to reduce the gain of the amplifier, because the upper volume range is otherwise unusable due to clipping. Replace this 39k resistor with a 20k resistor. Read the TDA3116 datasheet if you're interested.

Anyway, here are the project files:

• Power PCB
• Enclosure FreeCAD model

The parts:

• Amplifier board
• Boost converter
• BMS
• Buck converter
• Battery
• Bullet connectors
• Barrel plug with sense pin
• Parts on the PCB (look at the schematic), the MOSFET is not important, pick anyone with the same pinout and sufficient current and voltage ratings