Performance of Low Frequency Sound Zones Based on Truncated Room Impulse Responses

Using spatially distributed loudspeakers and properly designed control filters, it is possible to generate sound zones that play different audio contents in different regions of the same room. For low frequency content, the design of control filters relies on the room impulse responses (RIRs) between each loudspeaker and the desired listening positions. Estimates of the RIRs can be obtained by distributing wireless microphones within the sound zones and thereby systematically acquiring sufficient knowledge about the acoustical characteristics of the room and loudspeakers. Longer acquisition times would generally lead to better estimates of the RIRs but would also introduce processing delays, which is undesirable in cases where time-varying RIRs are to be compensated. In addition, shorter RIRs may imply lower computational complexity.