I'm having the same issue. Did anyone get this resolved by getting a replacement unit? Wondering if, like
@Indominus and
@uller6, it's something to do with my home in which case a new unit won't help.
I've contacted Apple Support so at least I've logged the issue and they are getting the feedback
I did get another Studio Display, and the new one had the exact same issue as the first one. So if its buzzing for one of them, it very unlikely it will be resolved by a different unit.
I also spoke to Apple Support multiple times, and each time I was told this is the first time someone is reporting an issue with electrical buzzing. Weird.
In my case, the main cause of the buzzing is due to the dimmers that I have installed in my house. They are supposed to be high quality dimmers (Lutron) but they are the root cause. Whenever the dimmers are turned on, it induces electrical noise into the power line that propagates throughout the house through the electrical panel. I believe in most homes there are 2 power lines in the house. I noticed that in my house most of the rooms are wired to one of the power lines and appliances in the other power line (laundry, fridge, ac, etc.). So basically almost all the dimmers in the house are on the same power line as the Studio Display.
I did some more testing and I noticed that the buzzing noise is also present in other devices as well. I used the Voice Memos app on the iPhone to record the air vents of my Mac Studio and the iMac that its replacing. Both have a buzzing noise similar to the Studio Display albeit much less audible. And both the Mac Studio and iMac have backward facing vents so that helps with the sound isolation while the Studio Display has upward facing vents which is why the noise is more noticeable.
Initially from my testing, I thought only the smart dimmers (Lutron Caseta) were creating this electrical noise. The standard Caseta dimmers don't have a neutral wire requirement. I got them replaced with a model that has a neutral wire and now when these dimmers are turned on, there is no buzzing noise. But I also have non-smart dimmers (Lutron Diva) installed throughout the house, and now these ones are causing the buzzing noise (from my initial testing they were not). I have a feeling that if I replace these with a Lutron Diva model that has a neutral wire, then the problem will be resolved. But this will take so much time that I'm avoiding this.
Its also possible part of this is because the LED pot lights that I have installed probably don't have good quality electronics. But again this will take too much time to diagnose. They were installed by a contractor and the brand is a contractor grade brand. Lesson learned here is to only buy things from well known consumer brands and those that are compatible with the dimmers you are getting (Lutron has a LED compatibility page). This will also help with warranty claims etc.
A Lutron Support agent recommended that I should get a power filter. He suggested the APC C2 Power Filter which is supposed to eliminate EMI/RFI noise in the power line and also provide surge protection. I have it ordered and it should be delivered this week. Hopefully this fixes the buzzing noise and I also get a good quality surge protector because supposedly the surge protection on the power strips aren't great.
