A Guide to the Implementation of Ambisonics Super Stereo

Authors: Alessio Mastrorillo, Giuseppe Silvi, Francesco Scagliola

Abstract:

This paper explores the decoding of Ambisonics material into 2-channel mixing formats, addressing challenges related to stereo speakers and headphones. We present the Universal HJ (UHJ) format as a solution, enabling the preservation of the entire horizontal plane and offering versatile spatial audio experiences. Our paper presents a UHJ format decoder, explaining its design, computational aspects, and empirical optimization. We discuss the advantages of UHJ decoding, potential applications, and its significance in music composition. Additionally, we highlight the integration of this decoder within the Envelop for Live (E4L) suite.

Keywords: Ambisonics, UHJ, quadrature filter, virtual reality, Gerzon, decoder, stereo, binaural, biquad.

References:

[1] M. Gerzon, “Ambisonics in multichannel broadcasting and video,” Journal of the Audio Engineering Society, p. 31, 1983.
[2] “Surround Discography website,” www.surrounddiscography.com, accessed: 2023-01-24.
[3] “Envelop for Live webpage,” https://www.envelop.us/software, accessed: 2023-01-24.
[4] “UHJ decoder for E4L,” https://github.com/EnvelopSound, accessed: 2023-01-24.
[5] Julius O. Smith III, Mathematics of the Discrete Fourier Transform (DFT), with Audio Applications - Second Edition. W3K Publishing, 2007.
[6] C. B. Gold, A. V. Oppenheim, “Theory and implementation of the discrete Hilbert Transform,” 1969.