 Penteo claims that its technology results in a more natural and more precise sounding surround experience without generating any artificial & unwanted sounds, and only Penteo is 100% ITU down-mix compatible back to the original stereo track.The Penteo process was first demonstrated publicly at the Surround Expo in Los Angeles in 2005 by John Wheeler of San Francisco, CA.In 2009, Penteo Surround LLC was founded and marketed Penteo 1