Which beeps... motor or ESC?

[gtranquilla]

I am now convinced that it is the motor that beeps when first powering up a Multirotor..... and not the ESC....
So where is the beeping device hidden inside of the motor? Or are my ears misleading me?

 

[Carapau]

Motor makes the beep by rapid oscillation driven by the ESC


Sent from my iPhone using Tapatalk

 

[Electro 2]

Motor makes the beep by rapid oscillation driven by the ESC

This is correct. Essentially, the ESC turns the motor into a rudimentary loudspeaker by feeding it DC chopped at a specfic rate which is a musical pitch. Some will play various tunes on boot.