An Alternative Ambisonics Formulation: Modal Source Strength Matching and the Effect of Spatial Aliasing

Zotter F, Pomberger H, Frank M. An Alternative Ambisonics Formulation: Modal Source Strength Matching and the Effect of Spatial Aliasing. In: AES Convention 126. Audio Engineering Society; 2009. Paper 7740. Available from: https://aes.org/publications/elibrary-page/?id=14936

@inproceedings{Zotter2009_14936,
  author = {Zotter, Franz and Pomberger, Hannes and Frank, Matthias},
  title = {{An Alternative Ambisonics Formulation: Modal Source Strength Matching and the Effect of Spatial Aliasing}},
  booktitle = {AES Convention 126},
  note = {Paper 7740},
  year = {2009},
  month = may,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=14936}
}

TY  - CPAPER
TI  - An Alternative Ambisonics Formulation: Modal Source Strength Matching and the Effect of Spatial Aliasing
AU  - Zotter, Franz
AU  - Pomberger, Hannes
AU  - Frank, Matthias
T2  - AES Convention 126
M1  - Paper 7740
PY  - 2009
DA  - 2009/05/06
UR  - https://aes.org/publications/elibrary-page/?id=14936
PB  - Audio Engineering Society
LA  - en
AB  - Ambisonics synthesizes sound fields as a sum over angular (spherical/cylindrical harmonic) modes, resulting in the definition of an isotropically smooth angular resolution. This means, virtual sources are synthesized with outstanding smoothness across all angles of incidence, using discrete loudspeakers that uniformly cover a spherical or cylindrical surface around the listening area. The classical Ambisonics approach models the fields of these discrete loudspeakers in terms of a sampled continuum of plane-waves. More accurately, the contemporary concept of Ambisonics uses a continuous angular distribution of point-sources at finite distance instead, which is considerably easier to imagine. This also improves the accuracy of holophonic sound field synthesis and the analytic description of the sweet spot. The sweet spot is a limited area of faultless synthesis emerging from angular harmonics truncation. Additionally, playback with loudspeakers causes spatial aliasing. In this sense, the contemporary concept allows for a succesive consideration of the major shortcomings of Ambisonics: the limited sweet spot size and spatial aliasing. To elaborate on this, our paper starts with the solution of the nonhomogeneous wave equation for a spherical point-source distribution, and ends with a novel study on spatial aliasing in Ambisonics.
ER  -