A system for determining motor speed of a brush DC motor, including a first filter for receiving a substantially low frequency portion of a sensed current of the motor and parameters corresponding thereto, for calculating a speed estimate of the motor; an adaptive bandpass filter having a center frequency corresponding to the speed estimate of the first filter, for receiving the sensed current and substantially isolating a first periodic current fluctuation thereof. A detected frequency of the first periodic current fluctuation corresponds to the speed of the brush DC motor. The system may include a tracking frequency selection block for selecting a frequency component of the sensed current and providing same to the first filter, wherein the speed estimate is based in part upon the selected frequency component.