In 1973, Michael Gerzon forged the term while describing his set of methods on how to a) record, b) process, c) distribute, and d) reproduce a full-sphere sound field.

The Latin preposition ambi means ‘on both sides’. It comes from the verb ambire, which denotes both the act of walking around and encompassing an area.

1. A‑Format:
   Microphone signals.
2. B‑Format:

   A‑Format that is processed into the spherical harmonics domain, containing all the information of a full-sphere sound field.

   It is independent of any loudspeaker configuration, but cannot be played directly.

3. C‑Format:

   B-Format in a concrete distribution form.

   AmbiX is the standard. It uses ACN channel ordering with SN3D normalisation. The proposed file format is CAF audio. Old but golden, without 4 GiB limit, as HOA grows quickly. (Technically other formats also can carry B‑Format, such as RF64 wav, BWF, or AIFF.)

4. D‑Format:
   C‑Format decoded to loudspeaker feeds or binaurally processed for headphone playback.

Our binaural decoder uses the MagLS algorithm proposed in [1].

It uses the same set of filters as the IEM BinauralDecoder plugin, and was realized for us with a custom build of the Atmoky WebSDK by Dr. Markus Zaunschirm and Christian Schörkhuber, Graz. Thank you again for not only professional results. It was an honor and a great pleasure working with you.

We were provided with a validation script, that shows -134.91 dB SNR as maximum delta between the WebAssembly compile and the original IEM plugin output, when fed with Dirac impulses and noise. Wow! :-)

[1] Schoerkhuber, Christian; Zaunschirm, Markus; Hoeldrich, Robert.
“Binaural Rendering of Ambisonic Signals via Magnitude Least Squares”,
Fortschritte der Akustik, DAGA, 2018

To achieve natural, consistent and reproducible results, make use of the IEM Plugin Suite. In particular put the IEM BinauralDecoder at the end of your audio signal chain.

7OA is supported in the marketplace.
3OA is supported in the web player.

Q: Only 3 orders?
A: Yes.

Depending on your needs, you have two options for binaural decoding via headphones or bypassing the decoder to output raw B‑Format for further processing on your side.

• Buffer Mode:

  Gain? No network hassle. Zero-latency seeking. Background playback.
  Drawback? Depending on your connection it takes a while before playback starts.

  All audio data is downloaded upfront via XHR, stitched together, and ready for Ambisonic decoding.

• Streaming Mode:

  Gain? Instant playback.
  Drawback? A solid internet connection is necessary. (20 Mbit/s upwards. 100 Mbit/s and you're fine.)

This marketplace is full-sphere-first. Please convert upfront, and you’re good to go.

The spatial audio community is diverse and not everybody considers height information as crucial to the equation, as we do. That point of view was held by one of the pioneers, the late Prof. Angelo Farina.

Michael Gerzon used the term pantophonic when referring to planar 360° and periphonic when referring to loudspeaker rigs with height information (e.g. a dome, a cube or a full-sphere layout).

• Waves Nx? Use Google Chrome. Press play on a Werck ⇨ Orientation: select "Bluetooth" ⇨ Aprove ⇨ Select "Waves Nx" ⇨ Enjoy.

• Supperware Head Tracker 1? Use Google Chrome / Firefox. Start Bridgehead.app ⇨ Select Quaternion (Composite) & 50 Hz. ⇨ Play a Werck ⇨ Orientation: Select "WebMidi" ⇨ Approve ⇨ Enjoy.

Try to view it less from the perspective of a product and more as a set of methods. Read the original papers, listen critically, decode to real loudspeaker arrays when ever possible. Ambisonics is useful, not just fashionable. It remains because the underlying questions were formulated carefully. The simplest advice I can give is still to go to a concert by an artist you care about. :)