Are you a music lover? Check out this simple DIY where the author has paired his smartphone with wireless speaker in less than a second without using Bluetooth or Wi-Fi.
Connection is really simple. Follow these steps:
1. Connect speakers at the right and left channel output.
2. Bridge right & left channel input and connect coil to this input.
3. Also provide required 5V and ground, also if required connect 2200uf capacitor at 5V input since amplifier will require more current when the amplitude of music is high.
4. Experimenting with different coils affects the audio, like a high voltage coil from the transformer will offer more trebel whereas low voltage coils produce more base in sound.