Static, constant-gain, output-feedback control compensators were designed to increase the transmission loss across a panel subjected to mean flow on one surface and a stationary, acoustic half-space on the opposite surface. The multi-input, multi-output control system was based upon the use of an array of colocated transducer pairs. The performance of the static-gain, output-feedback controller was compared to that of the full state-feedback controller using the same control actuator arrays, and was found to yield comparable levels of performance for practical limitations on control effort. Additionally, the resulting static compensators proved to be dissipative in nature, and thus the design varied little as a function of the aeroelastic coupling induced by the fluid–structure interaction under subsonic flow conditions. Several parametric studies were performed, comparing the effects of control-effort penalty as well as the number of transducer pairs used in the control system.