A velocity-controlled actuator system and method are usable in low velocity, high load situations such as those encountered in dynamic head loading, and in normal situations. The velocity-controlled actuator system utilizes a self-tuning estimator that is calibrated during operation of said disk drive. Consequently, parameters, characteristics, and any other features of the disk drive that affect operation of the actuator system are compensated for in real time by the calibration process. The velocity-controlled actuator system dynamically adjusts the actuator resistance utilized in the reconstruction of the back EMF voltage by utilizing a self-tuning estimate of the actuator resistance that compensates for any changes in the actuator resistance over time.