Robustness analysis of room equalization for soundfield reproduction within a region

Recent works on soundfield reproduction have presented several methods of recreating a desired soundfield within a region. Estimation or prior knowledge of the inverse reverberant channels now becomes an essential element of equalizing the room effects. However, it has been shown that designing point-to-point equalizers by sampling the reverberant soundfield is only practical within a few tenths of a wavelength of the sampled locations. This work investigates the robustness of the equalization process applied to a region, with respect to changing of actual microphone positions from their expected locations. We use a modal description of the equalized soundfield to obtain theoretical results for region equalization error due to positioning errors. Simulation results suggest that equalizing the reverberant soundfield recorded at multiple positions around the edge of the reproduction region is more immune to the positioning errors. © 2013 Acoustical Society of America