What decoding method is used in AmbiDecoder?

Johannes Schütt

Projection decoding is also sometimes called ‘sampling ambisonic decoding’ (SAD). It is the simplest form of ambisonic decoding. It samples the virtual panning function at the loudspeaker directions. SAD is optimal for loudspeakers arranged as t-design layouts, with $t \geqslant (2N+1)$ ($N$ being the Ambisonics order). Typically, the SAD should only be used for 2D loudspeaker layouts, i.e. arranged regularly in a circle. Avoids this decoder for 3D setups.

One of the caveats of the ambisonics decoding used in these tools is the strong requirement for REGULAR speaker layouts. The decoding method used (more of spatial sampling, according to R.Furse) will only give precise results if the speakers are evenly spaced in 3D. Any other layout will deteriorate the spatial imaging and introduce artifacts. Experience shows that speaker layouts that were measured out carefully, allowing for precise adjustment of the decoder, give the best results.

2021-05-26T15:21:54+00:00

Comments (2)

Johannes Schütt
Projection decoding is also sometimes called ‘sampling ambisonic decoding’ (SAD). It is the simplest form of ambisonic decoding. It samples the virtual panning function at the loudspeaker directions. SAD is optimal for loudspeakers arranged as t-design layouts, with $t \geqslant (2N+1)$ ($N$ being the Ambisonics order). Typically, the SAD should only be used for 2D loudspeaker layouts, i.e. arranged regularly in a circle. Avoids this decoder for 3D setups.

One of the caveats of the ambisonics decoding used in these tools is the strong requirement for REGULAR speaker layouts. The decoding method used (more of spatial sampling, according to R.Furse) will only give precise results if the speakers are evenly spaced in 3D. Any other layout will deteriorate the spatial imaging and introduce artifacts. Experience shows that speaker layouts that were measured out carefully, allowing for precise adjustment of the decoder, give the best results.
- 2021-05-26T15:21:54+00:00
Christian Schweizer repo owner
- changed status to resolved
- 2021-07-09T21:39:40+00:00
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