A sound field control device includes a surround decoder for decoding an input surround encode signal and generating three channel signals of L, C and R to be reproduced in front left, front center and front right and one channel signal of S to be reproduced in the rear, output terminals for outputting...http://www.google.fr/patents/US5727067?utm_source=gb-gplus-shareBrevet US5727067 - Sound field control device
