I built these Raspberry pi Speakers using mono amplifier boards from Sparkfun, 8 ohm speakers from All Electronics, a few components and some wood from my garage I have made four WIFI speaker boxes for Raspberry Pi based audio projects. Each speaker box has a Raspberry Pi in the back that runs a Pure Data audio patch. The Pure Data audio patch is controlled via OSC through a WIFI dongle on the Pi. The speaker is powered via the Pi’s 3.3 volt GPIO pin and ground.