Build the circuit first: power + wire + any synth circuit you want + wire + synth speaker + synth speaker.
Sandwich two mounting boards together. The sides that connect to littleBits should be facing outwards. It is always a good idea to put some gluedots in between to keep them together. Arrange two speakers, the power module + battery, and wires on one side of the mounting board.
Place M3 screws through the screw holes in each corner of the mounting board. Secure them in place with nuts.
Make the case out of acrylic. Laser cut it and glue it together with acrylic glue. You can download the template file that we used.
Attach a small piece of acrylic to the little black switch on the power module in order to make it accessible from the outside of the case.
Place the mounting boards into the acrylic case. The four screws on the mounting boards should pass through the four holes on the front panel of the case. Secure in place with nuts. You will want to make sure that the power cable and wires pass through their respective holes.
Snap your synth circuit on the mounting board on the back of the boombox. Hook it up to the power and the speakers with the wires coming from the front side. (Note: you may have to disconnect and reconnect the JST connectors on the wires to do this).
You are all set to pump up the volume on the street!