An active noise canceller outputs a noise pattern learning request signal to a hard disk drive causing the hard disk drive to perform a predetermined operation, receives noise at this moment through a sound-receiving unit, and stores, in a nonvolatile memory unit, a relationship between the noise and a head operation data signal output from the hard disk drive. Based on the operation data signal outputted from the hard disk drive, the active noise canceller generates a noise-canceling sound while making a reference to the above relationship stored in the nonvolatile memory unit. Therefore, the signal processing needs a low degree of response for operating the noise-canceling sound.

A disc drive device includes a base and a disc rotatably attached to the base. The disc drive also includes an actuator assembly rotatably attached to said base and a device for moving the actuator assembly. The actuator assembly includes an actuator arm and a transducer head in a transducing relationship with respect to the disc. The transducer is attached to the actuator arm. A method of screening disc drives for harmonic resonant frequencies includes sampling the position error signal at a track location in the disc drive, and determining the velocity of the position error signal from the sample of the position error signal. The velocity of the position error signal sample is divided by the position error signal to produce a quotient. The quotient is compared to a selected quotient threshold value to determine the type of a harmonic in the disc drive.

An active noise reduction system for reducing the acoustic noise generated by a hard disk drive or generated external of a hard disk drive. The active noise reduction system is integrated into the hard disk drive and produces an acoustic waveform that is 180 degrees out-of-phase with the acoustic noise being generated, for example, by the spindle motor and VCM. The acoustic noise is received directly through a microphone or indirectly through the read/write head, spindle motor driver, or VCM driver. The acoustic noise is processed by electronics and the noise canceling waveform is either retrieved from the hard disk drive's memory, disk, or generated by the electronics. The noise canceling waveform is then broadcasted through one or more transducers that are integrated in the hard disk drive.

A disc drive system includes a base with sidewalls, a spindle attached to the base, and at least one disc attached to the spindle. A cover is also included for attaching to the base. The cover and the base form a disc enclosure which encloses the at least one disc, a portion of the spindle, and the actuator assembly. The disc drive system also includes a cover that is the prime acoustical radiator from the disc drive. The cover includes at least one dampening member attached by the adhesive. The dampening member is provided with a cut or slit therein to shift the resonant frequency of the cover. The cut increases area with high value of shear deformation in the adhesive and increases the loss factor.