Y Axis motor is really loud
The sounds are mainly caused by the bed resonating with the stepper motor, and this will vary with the speed of the stepper motor. The best solution is to use "silent" stepper motor drivers (e.g. Trinamic), but you may be able to reduce the noise by:


Reducing the belt tension as much as possible.
Changing your print and/or move speeds.
Fitting a stepper motor damper.
Fitting TL smoothers (if you have A4988 drivers), although their efficacy is controversial.


I have done all of the above with good results.