First-order Ambisonics in MAN Wiki

:category:draft

## Introduction

The invention of first-order Ambisonics (FOA) in the mid-1970s by Michael Gerzon and Peter Fellgett was following the classical coincident audio recording and playback principles from the 1930s.

First-order Ambisonics is an extension of Blumlein's [[Stereophonic#ms_intensitybased|M-S recording system]].

## History of first-order Ambisonics

Felgett [1], Gerzon and Craven [2-4] were considered as the pioneers of the FOA technology. The scheme of M-S microphone system is extended to 3D first-order Ambisonics by a third figure-of-eight microphone of up-down aiming. [5]

### Gerzon's designing paper [2], March 1975 


### 2D FOA

### 3D FOA


## Other internet resources

- “Ambisonic.Net - where surround-sound comes to life.” Accessed: Apr. 01, 2025. [Online]. Available: [https://www.ambisonic.net/](https://www.ambisonic.net/)
- “Michael Gerzon Audio Pioneer.” Accessed: Apr. 01, 2025. [Online]. Available: [https://www.michaelgerzonphotos.org.uk/](https://www.michaelgerzonphotos.org.uk/)
- “Visualization XY stereo microphone system - Blumlein Eight/Eight 90° Intensity Stereo Blumlein Pair - Stereo recording angle SRA time difference level difference orchestra angle degrees visualisator XY MS figure-of-eight - sengpielaudio Sengpiel Berlin.” Accessed: Apr. 01, 2025. [Online]. Available: [https://sengpielaudio.com/Visualization-Blumlein-E.htm](https://sengpielaudio.com/Visualization-Blumlein-E.htm)
- “Into the Soundfield.” Accessed: Apr. 01, 2025. [Online]. Available: [https://intothesoundfield.music.ox.ac.uk/home](https://intothesoundfield.music.ox.ac.uk/home)
- “matthiaskronlachner.com | // audio visual art //.” Accessed: Apr. 01, 2025. [Online]. Available: [https://www.matthiaskronlachner.com/](https://www.matthiaskronlachner.com/)
- “Ambisonics in the 21st Century: A Review of Spatial Audio Techniques | CCRMA.” Accessed: Apr. 01, 2025. [Online]. Available: [https://ccrma.stanford.edu/blogs/mzeligs/ambisonics-in-21st-century-review-of-spatial-audio-techniques](https://ccrma.stanford.edu/blogs/mzeligs/ambisonics-in-21st-century-review-of-spatial-audio-techniques)
- “Ambisonic Studio.” Accessed: Apr. 01, 2025. [Online]. Available: [https://courville.uqam.ca/ambisonic/](https://courville.uqam.ca/ambisonic/)
- “Ambisonia.” Accessed: Apr. 01, 2025. [Online]. Available: [https://www.ambisonia.com/](https://www.ambisonia.com/)
- DAW and VST plug-ins:
	- [Aalto University SPARTA and COMPASS plug-ins](http://research.spa.aalto.fi/projects/sparta_vsts/)
	- [IEM Plug-in Suite](https://plugins.iem.at)
	- [Matthias Kronlachner's ambiX plug-ins](http://www.matthiaskronlachner.com/?p=2015)
	- [Blue Ripple Sound's O3A Core suite](http://www.blueripplesound.com/products/o3a-core)


## References

[1] P. Felgett, Ambisonic reproduction of directionality in surround-sound systems. Nature 252, 534–538 (1974)

[2] Gerzon, M.A. (1975). The Design of Precisely Coincident Microphone Arrays for Stereo and Surround Sound. _Journal of The Audio Engineering Society_. Download: [http://pcfarina.eng.unipr.it/Public/B-format/A2B-conversion/Gerzon/Design_Precisely_Coincident_Microphone_Arrays.pdf](http://pcfarina.eng.unipr.it/Public/B-format/A2B-conversion/Gerzon/Design_Precisely_Coincident_Microphone_Arrays.pdf)

[3] P. Craven, M.A. Gerzon, Coincident microphone simulation covering three dimensional space and yielding various directional outputs, U.S. Patent, no. 4,042,779 (1977)

[4] Gerzon, M.A. (1973). Periphony: With-Height Sound Reproduction. _Journal of The Audio Engineering Society, 21_, 2-10.

[5] Zotter, Franz & Frank, Matthias. (2019). Ambisonics: A Practical 3D Audio Theory for Recording, Studio Production, Sound Reinforcement, and Virtual Reality. 10.1007/978-3-030-17207-7. Download: [https://link.springer.com/content/pdf/10.1007/978-3-030-17207-7.pdf](https://link.springer.com/content/pdf/10.1007/978-3-030-17207-7.pdf)