Ambisonics is a fancy name for fairly basic concept. All the sound at single point adds up to a scalar number over time, but that captures no sense of direction

Ambisonics is a fancy name for fairly basic concept. All the sound at single point adds up to a scalar number over time, but that captures no sense of direction. The idea of Ambisonics is to characterize the sound field over a sphere. You can imagine the if you captured "pixels" of sound over a sphere the size of your head, as you turned your head, you'd be able to localize sound because mid and high frequencies would have wavelengths smaller than the sphere. The idea of Ambisonics is to encode this spherical sound signal in the form of its spherical (spatial) Fourier transform. That way, you can drop almost all of the higher coefficients, as a form of lossy compression. In fact, most systems just capture the first-order spherical harmonics, which is enough to do a good job localizing a single sound. Conveniently, you can do this with no computation, using just 4 standard mics in the right configuration. Spatial discrimination of multiple sound sources will be limited unless you capture higher order coefficients, which requires a much more sophisticated setup. The second part about Ambisonics is that now that you have this handy spatial signal, you can map it back to an arbitrary speaker setup to approximate the original sound field over that sphere, if you know where the speakers are placed. In many ways, it's far more scientific than much more common forms of multichannel audio, like stereo or 5.1. But that's kind of the downfall, because it doesn't necessarily map to that many real world use cases. In the real world, we dynamically navigate fields of sound, but Ambisonics is only going to capture sound at a predetermined point in space. If you imagine the edits in a video, the visual point of view is constantly changing. I suspect doing the same with audio wouldn't be as effective, but who knows?