If you upgraded MK3>MK4>MK4S to a Core One, buy new motors  

If you upgraded MK3>MK4>MK4S to a Core One, buy new motors

I struggled with my Core One being obnoxiously loud. Not resonance, the latest firmware and profiles helped with that. But motor whine. Like a DJ scratching records or an old generation 1 printer, just loud shrilling motors. I never had an issue with my MK4S and motor noise, it was very quiet silent and I often had to check to see if it was running. After upgrading the Core One, the amount of high pitched noise was unbearable to me. 

I saw a few Reddit comments of people replacing stepper motors, and that it made a difference. I decided to do the same, I bought new motors and its like a whole new printer. I can't hear the printer in the other room, I can't hear it with a headset on. Neither we true before. Its not dead quiet, it still hits resonance here and there, and you can hear the large linear bearings slide around. But compared to before, its much more enjoyable to be around. 

So if you have been upgrading your printer from MK3 (pre 2024), and you have X/Y steppers labeled "Prusa I3", then you should replace them and buy the accelerometer kit. The majority of the noise from my printer is now coming from it shaking the table its on and it occasionally passing through a resonance. 

I had a chat with support, there is the potential the older motors simply cannot be driven like the newer motors and its an issue in the firmware. Who knows.