Sound Field Reproduction by Combination of Circular and Spherical Higher-Order Ambisonics: Part II—Hybrid System

Grandjean P, Berry A, Gauthier PA. Sound Field Reproduction by Combination of Circular and Spherical Higher-Order Ambisonics: Part II—Hybrid System. J Audio Eng Soc. 2021;69(3):166-181. doi:10.17743/jaes.2020.0073

@article{Grandjean2021_21025,
  author = {Grandjean, Pierre and Berry, Alain and Gauthier, Philippe-Aubert},
  title = {{Sound Field Reproduction by Combination of Circular and Spherical Higher-Order Ambisonics: Part II—Hybrid System}},
  journal = {Journal of the Audio Engineering Society},
  volume = {69},
  number = {3},
  pages = {166--181},
  year = {2021},
  month = mar,
  publisher = {Audio Engineering Society},
  doi = {10.17743/jaes.2020.0073},
  url = {https://doi.org/10.17743/jaes.2020.0073}
}

TY  - JOUR
TI  - Sound Field Reproduction by Combination of Circular and Spherical Higher-Order Ambisonics: Part II—Hybrid System
AU  - Grandjean, Pierre
AU  - Berry, Alain
AU  - Gauthier, Philippe-Aubert
T2  - Journal of the Audio Engineering Society
J2  - J. Audio Eng. Soc.
VL  - 69
IS  - 3
SP  - 166
EP  - 181
PY  - 2021
DA  - 2021/03/06
DO  - 10.17743/jaes.2020.0073
UR  - https://doi.org/10.17743/jaes.2020.0073
PB  - Audio Engineering Society
LA  - en
AB  - This two-part paper explores 3-D sound field reproduction by combining low order spherical ambisonics and high order circular ambisonics in order to provide higher resolution in the horizontal plane. Part I is dedicated to rigorously establishing the solution of the Sound Field Reproduction (SFR) problem for a circular distribution of sources with either cylindrical harmonic or spherical harmonic expansions. In this second part the concept of spatial filtering is presented. A spatial low-pass filter using spherical harmonic expansion ensures proper reconstruction of elevation cues. Similarly a spatial high-pass filter using only higher orders of a circular harmonic expansion extends the zone of accurate reproduction in the horizontal plane. Numerical simulations of the hybrid system, based on the combination of the two spatial filters, are carried out and compared with the results of the classical spherical Higher-Order Ambisonic approach. The accurate reproduction area in the horizontal plane is larger in the case of the hybrid method than with the spherical approach, be it for sound pressure, direction-of-arrival, or sound field diffuseness. This method therefore makes it possible to extend the reconstruction zone in the horizontal plane by adding sources in the equator of a spherical array.
ER  -