Optimizing loudspeaker placement based on modal domain analysis for multizone sound field reproduction

Multizone sound field reproduction attempts to produce independent sound environments in a number of zones of space, providing the listener with a personalized listening experience. Many reproduction methods have been proposed to optimize the driving weights to improve reproduction performance for a given loudspeaker array configuration. Recently, various methods have explored to optimize loudspeaker placement for further improving the performance of multizone sound field reproduction. However, these methods are currently based on the pressure matching method to carry out the placement optimization study. This paper proposes a loudspeaker placement optimization method based on modal domain. An optimization model for multizone sound field reproduction is used to determine the global modal coefficients that enable the desired sound field to be accurately reproduced in the bright zone while limiting the whole sound field energy within the dark zone, where the global modal coefficients are transformed to the local modal coefficients by the harmonic translation theorem. The constrained matching pursuit method is used to select the optimal loudspeaker placement according to the obtained global modal coefficients. The driving weights of the selected loudspeakers are calculated by the pressure matching method. The simulation results and experimental results demonstrated the good potential of the proposed loudspeaker placement optimization method in multizone sound field reproduction.