Quote
o_lampe
The steppers will always hum when the drivers are active. So a brake on the axis and disabling the stepper drivers is mandatory.
With correctly-chosen drivers and a well-regulator power supply, the only "hum" should be ultrasonic. The motors on my printer produce just a very faint hum when stationary, which I believe is caused by ripple on the power supply output. You can often reduce the motor current when the motors are not moving, which reduces any hum caused by ripple (as it does on my printer). So it may be possible to avoid the need for a brake by using a sufficiently well-regulated power supply and/or reducing motor current to the minimum needed when stationary.