Q: How do I hook up my outdoor speakers?
I have never seen speakers with 3 wires coming
Out the back.

A: It sounds like it may be a commercial speaker that has wiring provisions for different power settings when connected to a commercial 70-volt audio system.

The best thing you could do is to verify exactly what the speaker is designed to do or simply start over again by purchasing a standard home audio loudspeaker.

Did the speaker not come with a manual or did you buy it used?

The only time I’ve seen outdoor speakers with the extra wire is if they include a built in light. Does this speaker have a light?