The AudioBox AB64 is a hardware-based system for sound reproduction and control in a stage setting. It is made up of a 64×64 channel matrix mixer a 64 channel hard-disk record/playback system and show-controller software based on the MIDI show control protocol. The hardware is hosted in a 2U rack unit.
TTA Track The Actors transforms mono signals from actors to a maximum of 16 speaker channels. By using psychoacoustic theorems the sound is given direction. The stage floor is divided into small squares (audio zones). The actors wear small small radio transmitters used to determine what zone they are positioned in. Each audio zone has a distinct matrix setup to allow the sound seemingly to originate from this point on stage with smooth transitions between the audio zones. The system supports up to 32 inputs and 16 outputs. TTA is a Norwegian company. I’ll have to get in touch with them.
As far as I can see it is not stated what principle is used for diffusion of sound in the above solutions. Also they seem limited to dynamic playback of prerendered sound files or real-time diffusion of live sources respectively. None of them seem to offer more complex show-scripted live processing and diffusion of sound.