In-room sound reproduction using active control: Simulations in the frequency domain and comparison with wave field synthesis

Abstract

Active sound control simulations were performed for progressive sound field reproduction over a ‘‘large’’ area using multiple monopole loudspeakers. The model is limited to the simulation of the acoustical output of the prescribed loudspeaker array in a simple room, and is based on achieving an optimal control in the frequency domain. This rather simple approach is chosen for this first feasibility study concerning a limited number of possible configurations of sensing microphones and loudspeakers. Other issues of interest concern the comparison with wave field synthesis, the control mechanisms and transducer configurations. As it is demonstrated, in-room reproduction of sound field using active control can be achieved with a residual normalized squared error below 2% while open-loop wave field synthesis gives more than 100% of error in the same situation. Usage of active control technique suggests the possibility to automatically overcome the room’s natural dynamics. A special surrounding configuration of sensors is introduced for a sensor-free listening area. [Work supported by NSERC, NATEQ, VRQ, and Université de Sherbrooke.]