Using the GPIO pins – Raspberry Pi Stack Exchange

Welcome,

What would be the purpose of tying 2 GPIO together? You can link them but then they will be dependant on each other and I can’t see any use case.

To play sound, you will need an analog signal. A basic gpio can’t provide that kind of signal. You will need an Digital to Analog Converter (DAC) to convert your audio stored in your raspberry as an array to an analog signal and then amplify it before sending it to a speaker.

Hope it helps, I invite you to google DIY speakers made from Raspberry pi.