Hexaphonie
A 6-channel format for picking up a sound sphere; developed by Madeleine Sola and Daniel Torsière at Radio France in the 1970s.
The format consists of a top layer triangle of three cardioid microphones spaced 35 cm and angled 120° relative to each other. In addition, a bottom layer spaced 35 cm below the top layer, consists of three cardioid microphones also arranged in a triangle like the upper layer. However, the bottom layer is rotated by 60° relative to the top layer. For the reproduction, each channel feeds one loudspeaker arranged in a similar configuration as the microphones.