Zylia ZM-1 vs. Harpex Spcmic: A Case Study of Higher-Order Ambisonic Recording Performance

Mróz B, Zaporowski S. Zylia ZM-1 vs. Harpex Spcmic: A Case Study of Higher-Order Ambisonic Recording Performance. In: Express Paper. Audio Engineering Society; 2026. Paper 447. Available from: https://aes.org/publications/elibrary-page/?id=23166

@inproceedings{Mroz2026_23166,
  author = {Mróz, Bartłomiej and Zaporowski, Szymon},
  title = {{Zylia ZM-1 vs. Harpex Spcmic: A Case Study of Higher-Order Ambisonic Recording Performance}},
  note = {Paper 447},
  year = {2026},
  month = may,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=23166}
}

TY  - CPAPER
TI  - Zylia ZM-1 vs. Harpex Spcmic: A Case Study of Higher-Order Ambisonic Recording Performance
AU  - Mróz, Bartłomiej
AU  - Zaporowski, Szymon
M1  - Paper 447
PY  - 2026
DA  - 2026/05/28
UR  - https://aes.org/publications/elibrary-page/?id=23166
PB  - Audio Engineering Society
LA  - en
AB  - The Zylia ZM-1 (103mm spherical array, 19 MEMS capsules, 3rd-order) and Harpex Spcmic (170mm planar array, 84 MEMS capsules, 5th-order capable) represent two distinct geometrical approaches to higher-order Ambisonics capture. Despite widespread adoption, systematic comparison of their performance under real recording conditions is absent from published literature. We present a controlled case study based on simultaneous recordings of solo piano repertoire in a 370-seat concert hall (Aula Politechniki Gdanskiej, RT60 = 1.97 s), with both arrays mounted 17 cm apart on a single stereo bar. After peak-normalization to 0:5 dBTP, four metrics were compared: W-channel spectral response, integrated loudness (ITU-R BS.1770-5), per-order spatial energy distribution, and first-order directional ratios. The headline finding concerns spatial energy: at nominally identical 3rd-order, the ZM-1 attenuates 27.4 dB from 0th to 3rd order, while the Spcmic attenuates only 8.4 dBa 19.0 dB gap that is not driven by aliasing-band content and persists across repertoire. The results indicate that nominal Ambisonics order alone does not predict per-order energy distribution in real recordings; geometry and encoding contribute substantially even when the format label is identical. Recordings are openly available under CC BY-NC-SA 4.0 (10.34808/5xe2-ah94).
ER  -