DIY Wireless Speakers – Part 1: Transmitter

Welcome to my DIY wireless speakers tutorial. We will be building/modifying an FM receiver and FM transmitter to turn them into wireless speakers. First we’ll build the FM transmitter.

To do this, we’ll modify a car FM transmitter (available on eBay). These are a popular solution for cars without AUX connectors, you can connect an iPod’s headphone jack to the FM transmitter, and hear your audio over the radio.

To use this device, we’ll have to make a few modifications. First, I removed the 5V power supply circuitry, which wasn’t necessary anymore. Then I soldered an old USB cable to the output of the 5V supply. Now we can power the circuit over USB instead of car power.

To get the audio into the mix, I replaced the 3.5mm female port with the end of an old pair of headphones, so that we could plug it into the back of, say, a TV.

For aesthetics, I built the circuit into a black box, and cut out holes for the cables.

Now we have an FM transmitter, next we need the receiver. Stay tuned for part 2!