A method and system are disclosed for compensating disturbance applied to a plant, such as a HDD component, controlled by a state control device having an estimator & controller. The estimator & controller is adapted to generate a first control signal in response to a state signal indicating an estimated state of the plant. A second control signal is generated by applying a transfer function H(s) having defined gain/frequency characteristics to a control signal derived from the first control signal. An overall control signal is generated in response to the second control signal and the control signal derived from the first control signal and applied to the plant.