The present application discloses a method to reduce hard-disk vibrations. The method to reduce hard-disk vibrations is for an electrical device having a hard-disk and a speaker, and the method to reduce hard-disk vibrations includes: determining a vibration value of the hard-disk when the speaker outputs an audio signal; determining whether the vibration value exceeds a predetermined vibration value; when the vibration value exceeds the predetermined vibration value, adjusting the audio signal into an adjusted audio signal via a reducing vibration equalizer; and outputting the adjusted audio signal by the speaker, wherein an amplitude of a predetermined frequency of the adjusted audio signal is smaller than an amplitude of the predetermined frequency of the audio signal.