Decomposition of high order Ambisonic recordings for reproduction using irregular loudspeaker arrays

摘要

Ambisonics is a technique for sound field synthesis and reproduction that has shown promising results for the presentation of three dimensional sound spaces. Sound fields are naturally represented by their expansions in terms of spherical harmonic functions; such descriptions are known as Ambisonic encodings. Precise regeneration of the sound field from a set of spherical harmonic expansion coefficients requires a sufficient number of loudspeakers arranged in a regular layout. Decoding of Ambisonic recordings for their reproduction using a spherical, uniform loudspeaker array is not difficult. Nevertheless, evenly distributing a large number of loudspeakers is unfeasible in most scenarios. Irregular configurations are known to lead to ill-conditioned and singular re-encoding matrices. We propose a method to decompose high order Ambisonic recordings, based on the geometry of the target array, for accurate reproduction over irregular loudspeaker arrays.