Filterbank rule for spherical microphone array encoding and EQs for above aliasing, transducers, and binaural playback

Zotter F. Filterbank rule for spherical microphone array encoding and EQs for above aliasing, transducers, and binaural playback. In: Convention Paper. Audio Engineering Society; 2024. Paper 10690. Available from: https://aes.org/publications/elibrary-page/?id=22503

@inproceedings{Zotter2024_22503,
  author = {Zotter, Franz},
  title = {{Filterbank rule for spherical microphone array encoding and EQs for above aliasing, transducers, and binaural playback}},
  note = {Paper 10690},
  year = {2024},
  month = jun,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=22503}
}

TY  - CPAPER
TI  - Filterbank rule for spherical microphone array encoding and EQs for above aliasing, transducers, and binaural playback
AU  - Zotter, Franz
M1  - Paper 10690
PY  - 2024
DA  - 2024/06/06
UR  - https://aes.org/publications/elibrary-page/?id=22503
PB  - Audio Engineering Society
LA  - en
AB  - Compact rigid-sphere microphone arrays are used to record 3D-sound scenes from one recording perspective. They are often used as the main microphone array in field recordings using Ambisonics. For time-invariant Ambisonic encoding, the array signals are typically first decomposed into spherical harmonic coefficient signals by a matrix, which are then equalized by radial filters, which need to be regularized by, e.g., a filter bank. This paper shows: (i) a simple way to determine common transducer responses for equalization based on comparison with an omnidirectional reference, (ii) a heuristic rule to define the filterbank frequencies depending on the Ambisonic order, diffuse-field-normalized weightings basic or max-rE, and available SNR, (iii) the appropriate handling of frequencies above the arrays spatial aliasing limit, and finally while the proposed solution supports loudspeaker playback: (iv) binaural playback requires a different equalization.
ER  -