As in a compartment of an automotive vehicle, when a left- and a right-channel loudspeakers are disposed at angularly different positions from each other with respect to a frontward direction of a listening position, there will be formed a sound field laterally asymmetric with respect to...http://www.google.ca/patents/US5710818?utm_source=gb-gplus-sharePatent US5710818 - Apparatus for expanding and controlling sound fields
