Three-Dimensional Sound Field Reproduction Using Multiple Circular Loudspeaker Arrays

Abstract

Abstract-Three dimensional (3D) spatial sound field reproduction enables enhanced immersive acoustic experience for a listener. Recreating an arbitrary 3D spatial sound field using a practically realizable array of loudspeakers is a challenging problem in acoustic signal processing. This paper exploits the underlying characteristics of wavefield propagation to devise a strategy for accurate 3D sound field reproduction inside a 3D region of interest with practical array geometries. Specifically we use the properties of the associated Legendre functions and the spherical Hankel functions, which are part of the solution to the wave equation in spherical coordinates, for loudspeaker placement on a set of multiple circular arrays and provide a technique for spherical harmonic mode-selection to control the repoduced sound field. We also analyze the artifacts of spatial aliasing due to the use of discrete loudspeaker arrays in the region of interest. As an illustration, we design a a third order reproduction system to operate at a frequency of 500 Hz with 18 loudspeakers arranged in a practically realizable configuration.

Parameterization of the three-dimensional room transfer function in horizontal plane

“…We propose the mode-matching on circles 17 to derive the weight vector of the loudspeaker array for generating a specific unit-amplitude outgoing wave of order n 0 and mode m 0 . The unit-amplitude outgoing wave can be expressed as …”

Sidelobe suppression by desired directivity pattern optimization for a small circular loudspeaker array

“…The PMM is an extension of inverse filtering [21]. Second, the wavenumber domain has recently attracted attention because the filter coefficients, the radiation patterns of a loudspeaker array, and the corresponding gains can be derived analytically [22][23][24][25][26][27][28][29]. However, the wavenumber domain can currently be used for specific array configurations, namely, linear, cylindrical, circular, and spherical configurations.…”

3D exterior soundfield capture using pressure and gradient microphone array on 2D plane

“…Soundfield analysis based on spherical harmonic decomposition is widely utilised throughout audio acoustic applications of spatial soundfield recording [1], [2], [3], reproduction [4], [5], beamforming [6], [7] and source localization [8]. At the heart of these applications are the microphone and loudspeaker arrays used for three-dimensional (3D) spatial soundfield sampling and reconstruction.…”