An actuator assembly is provided that includes a body portion, a first actuator arm assembly, a second actuator arm assembly, a first flexure assembly, and a second flexure assembly. Each of the first and second actuator arm assemblies projects from the body portion and has a distal end with different respective first and second mechanical configurations, sometimes referred to herein as "mounting configurations." Each of the flexure assemblies is respectively mounted to the distal ends of the first and second actuator arm assemblies via the respective mounting configuration. The first and second mechanical configurations (mounting configurations) are selected to provide the first and second flexure assemblies with different mechanical resonance characteristics. In a preferred embodiment, the second actuator arm assembly includes an actuator arm and a spacer disposed between the actuator arm and the second flexure assembly. The spacer has a stiffness different from the stiffness of the actuator arm.