Abstract: An apparatus for cancelling vibrations includes a reference signal representative of the vibrations to be cancelled, an adaptive control filter producing an output signal based on the reference signal, and an actuator responsive to the output signal to produce vibrations which destructively interfere with the vibrations to be cancelled. The adaptive control filter comprises a circuit for transforming the reference signal into its frequency components, a processor for applying weights to these frequency components, and another circuit for combining the weighted frequency components to provide the output signal of the adaptive control filter. The circuit for transforming utilizes N integer updates of the reference signal to resolve the reference signal into its frequency components. Further, the circuit for transforming is updated n times between successive transformations of the reference signal into its frequency components, where 1<n<N.