A method and apparatus for preserving matrix-surround information in encoded audio/video includes a receiver operative to receive matrix-surround encoded audio signals via a modem, separate the audio signals into a frequency spectrum having discrete audio frequencies, and determine a cutoff threshold...http://www.google.com.au/patents/US20030231774?utm_source=gb-gplus-sharePatent US20030231774 - Method and apparatus for preserving matrix surround information in encoded audio/video
