The minimum number of speakers for a horizontal ambisonic setup is 4 but you need at least 6 to localize sound in a full sphere: https://en.wikipedia.org/wiki/A

The minimum number of speakers for a horizontal ambisonic setup is 4 but you need at least 6 to localize sound in a full sphere: https://en.wikipedia.org/wiki/Ambisonic_reproduction_systems#Horizontal_vs._full-sphere_accuracy https://en.wikipedia.org/wiki/Ambisonic_reproduction_systems... I'm not sure if massive speaker array systems like BEAST (http://www.beast.bham.ac.uk/about/ http://www.beast.bham.ac.uk/about/) use ambisonic diffusion techniques, I think part of the appeal of ambisonics is the relatively small number of speakers you need for full sphere spatialization. (It's also interesting to see this subject pop up here. Maybe because Zoom is offering a consumer option now? I've heard good things about the octomic: http://www.core-sound.com/OctoMic/1.php http://www.core-sound.com/OctoMic/1.php )