A control system for a cutting reel unit includes a height-of-cut adjusting system and a reel-to-bedknife clearance adjusting system. The height-of-cut adjusting system includes a first frame; a second frame; a cutting reel supported by the second frame; a bedknife arranged adjacent to the cutting reel and supported by the second frame; at least one support element arranged to translate along the ground and arranged to support the first frame; and at least one first actuator connected between the first frame and the second frame and arranged to adjust the relative elevation of the second frame with respect to the first frame. The reel-to-bedknife clearance adjusting system includes at least one second actuator operatively connected between the reel and the second frame and a sound detector. The reel mower cutting unit may be manual or self-adjusting. In the manual mode, adjustments can be made by engaging and turning an adjustment actuator on the side of the cutting reel with a hand tool such as a socket wrench. In the self-adjustment mode, adjustments can be made by engaging and turning adjustment actuators with an output shaft of an electric motor. The same adjustment actuators are used in both adjustment modes, and the reel cutting unit may be converted between modes by fastening or unfastening electric motor assembly from the unit.