For reducing vibrations and noise in electrical machines a rotor is mounted in a magnetic alignment device while a bearing shield is loosely held relative to a stator. The rotor is driven by the stator and vibrations of the rotor are detected. A magnetic alignment device is controlled so as to reduce the vibrations. Finally the bearing shield is fixed to the stator in a position determined by the controlling of the magnetic alignment device. Thus electromagnetic forces are taken into consideration during vibration and noise reduction.