Analogies and differences between three methods for sound field reproduction

A theoretical comparison is undertaken, between three approaches for the reproduction of a sound field. The first method is based on the decomposition of the sound field in terms of spherical harmonics (as High Order Ambisonics), the second method is derived from the Kirchhoff-Helmholtz integral(as Wave Field Synthesis) and the third approach relies on the solution of Least Squares algorithm. The study focuses on reproduction systems including a spherical array of secondary sources. The study is purely analytical, and is carried out in the framework of the theory of integral equations. Analogies anddifferences between the three techniques are discussed and the important link between the theory of sound field reconstruction and the theory of acoustic scattering is presente