Low level buzzing coming from tweeters.

No, if the system is all on one side of the breaker box with one on top of each other then that is causing the hum. The breakers are staggered.
https://images.search.yahoo.com/search/images?p=breaker+box+inside+pictures&fr=yfp-t&imgurl=...
https://i.pinimg.com/originals/b1/04/95/b10495877e448c7626e2b9046f295001.jpg

ozzy

@atmasphere 
Yes, it is a pole, about 15-20’, driven into the ground with ground wires fused to it.

@ozzy 
Yes, the dual 30 amp breaker is near the top of the right side of the box and the 20 amp breaker is also on the right side near the bottom. There are five “blanks” and two more breakers between them.

I’m trying to contact the electrician who installed the panel and the outside ground.

I appreciate all the input!

FWIW, you are far better off if the ground is tied to the water mains as is traditional. Stakes in the ground tend to be variable, and if the ground connection is indeed on the water mains, the stake in the ground should not be used at all unless all your water connections involve plastic pipes.

The water main should be iron, as it is an older house (1957). I’ve got the same pole type, but separate, ground for my large portable generator. Another discussion with my electrician. We’ve touched base and he will be coming over to check things out.

atmasphere

... you are far better off if the ground is tied to the water mains as is traditional. Stakes in the ground tend to be variable, and if the ground connection is indeed on the water mains, the stake in the ground should not be used at all unless all your water connections involve plastic pipes

I'm surprised to see Ralph state this. IMO, you are best served by complying with NEC and local codes. That usually requires stakes in the ground bonded to the ground in the service panel.