Investigation of loudspeaker array layout for sound field reproduction by room-mode matching in rectangular rooms

Sound field reproduction, a technique for reproducing a wide range of sound fields, has several practical issues, such as the degradation of spatial reproduction accuracy due to room reflections. For reproducing the sound field in the low-frequency range where room modes are prominent, mode matching has already been proposed using the room mode as a basis function. In this paper, as an extension of room mode matching, we propose an approach to extend the desired sound field using a discrete cosine transform by approximating the eigenfunction of a rectangular closed space as a cosine function since most rooms can be regarded as rectangular rooms at low frequencies. We have investigated loudspeaker array geometries suitable for room-mode driving in simulations and have shown that a rectangular loudspeaker array surrounding the entire room is the most effective.