On the Use of a Lebedev Grid for Ambisonics

Lecomte P, Gauthier PA, Langrenne C, Garcia A, Berry A. On the Use of a Lebedev Grid for Ambisonics. In: AES Convention 139. Audio Engineering Society; 2015. Paper 9433. Available from: https://aes.org/publications/elibrary-page/?id=17989

@inproceedings{Lecomte2015_17989,
  author = {Lecomte, Pierre and Gauthier, Philippe-Aubert and Langrenne, Christophe and Garcia, Alexandre and Berry, Alain},
  title = {{On the Use of a Lebedev Grid for Ambisonics}},
  booktitle = {AES Convention 139},
  note = {Paper 9433},
  year = {2015},
  month = oct,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=17989}
}

TY  - CPAPER
TI  - On the Use of a Lebedev Grid for Ambisonics
AU  - Lecomte, Pierre
AU  - Gauthier, Philippe-Aubert
AU  - Langrenne, Christophe
AU  - Garcia, Alexandre
AU  - Berry, Alain
T2  - AES Convention 139
M1  - Paper 9433
PY  - 2015
DA  - 2015/10/06
UR  - https://aes.org/publications/elibrary-page/?id=17989
PB  - Audio Engineering Society
LA  - en
AB  - Ambisonics provide tools for three-dimensional sound field analysis and synthesis. The theory is based on sound field decomposition using a truncated basis of spherical harmonics. For the three-dimensional problem the decomposition of the sound field as well as the synthesis imply an integration over the sphere that respects the orthonormality of the spherical harmonics. This integration is practically achieved with discrete angular samples over the sphere. This paper investigates spherical sampling using a Lebedev grid for practical applications of Ambisonics. The paper presents underlying theory, simulations of reconstructed sound fields, and examples of actual prototypes using a 50 nodes grid able to perform recording and reconstruction up to order 5. Orthonormality errors are provided up to sixth order and compared for two grids: (1) the Lebedev grid with 50 nodes and (2) the Pentakis-Dodecahedron with 32 nodes. Finally, the paper presents some practical advantages using Lebedev grids for Ambisonics, in particular the use of sub-grids working up to order 1 or 3 and sharing common nodes with the 50 nodes grid.
ER  -