Quadraphonic sound replay system - has four loudspeakers at outer corners of isosceles triangle whose apices touch at listeners head

摘要

The quadrophonic sound replay system, for sounds recorded using a dummy head, ensures correct direction localisation and 'all-round' sound. The first signals each from one of the dummy head's microphone channels are passed directly to or stored before passing each to one of the two front loudspeakers (VL,VE). The second signals (opposite in phase to the first signals and delayed and having different spectra and levels) are passed each to the appropriate rear loudspeaker (HR,HL) lying diagonally opposite the corresponding front loudspeaker. The 4 loudspeakers lie at the outer corners of isosceles triangles whose apices touch at the listener's head.