Robust sound field reproduction integrating multi-point sound field control and wave field synthesis

For a reproduced sound field, the competing goals between the listening area and reproduction accuracy in an actual environment is one of the most important problems in sound field reproduction using loudspeakers. In this paper, we propose a new method of balancing these goals with absolute accuracy using an inverse filter of the room acoustics: the null space of a generalized inverse matrix given by a compensation filter of the wave field outside the control points. To develop an expression for the compensation filter, we use the loudspeaker driving function of wave field synthesis (WFS) in stead of the filter used in conventional studies. By using WFS, the proposed method overcomes the compensation limitation of auditory distance and azimuth perception outside the control points. The results of computer simulations revealed that the proposed method balances the competing goals and has wide applicability in a spatial domain with high accuracy of reproduction both under free-field conditions and in a simulation model with room reflection.