New Plugins: O3A Spatial Audio

Posted: 7 June 2023

The O3A Spatial Audio plugin library is a set of special decoders exporting to object-based "Spatial Audio" formats like Dolby Atmos and Apple Spatial Audio.

These formats seem to be becoming more prevalent, and some don't support higher order ambisonics directly yet. They mostly do support 7.1.2 or 7.1.4 however, and so it has been possible to decode ambisonics into a bed suitable for use with these formats using decoders like O3A Decoder - 7.1.2 (Dolby Atmos). This works okay, but we've been wondering if there are better approaches.

The O3A Spatial Audio plugins work differently. Instead of producing audio for a 7.1.2 bed, they assume a number of virtual speaker objects at fixed positions in a "dome" configuration, and produce audio to be fed to them. The audio for these virtual speakers can then be panned into place in a Spatial Audio mix, for instance in Logic.

Currently there are 20, 24, 32 and 64-channel domes in the library. At the time of writing, it is a little unclear how many objects will work best with different Spatial Audio systems, so we've provided a few different options. Please let us know how you get on.

We've also added some words on Spatial Audio to our technical notes section, to try to demystify things a little.