Active feedback control was used to modify the acoustic/structural dynamics in a reverberant acoustic enclosure. The physical system was modeled as a single-input, multi-output system and an H??, design approach was used to obtain a robust controller. Experimentally obtained results exhibited a significant reduction in the dominant acoustic modes. Furthermore, the controller was seen to be effective in achieving noise reductions in the region of space surrounding the sensor, thus indicating that localization of the noise reduction was not a limiting factor in the design.