a servo - controlled , head actuator design that has low profile characteristics in both the height and width dimensions . the low height allows the actuator to fit into a half - high tape drive form factor . additionally , in some implementations , the actuator comprises a smaller , concentrated moving mass coupled with a flexure construction having a narrowed width with added ribs for torsional stiffness . these aspects of the actuator provide a higher second mode of vibration compared to the flexure designs of the prior art . the actuator includes a coarse actuator assembly for larger movements of the head , and a fine actuator , including a voice coil motor , responsive to analysis of servo signals . in some embodiments , the voice coil motor of the fine actuator and the coarse actuator shafts are in line . since the centerlines of the shafts are in - line with the voice coil motor , the resonance response of the shaft spring - mass system is reduced .