Wolf pup 16 ft 2022 outdoor speakers humming

That's really weird. There must be power somewhere. Does the noise happen even when it's dark outside? If only during the day I'm thinking it's the solar causing the noise. If so you can try throwing a blanket over the solar and see if the noise suddenly stops. When you say the solar is not hooked up how is it disconnected? Is it just a removed fuse or are the panels not plugged into anything or ????