10.2 surround sound

10.2 is the surround sound format developed by THX creator Tomlinson Holman of TMH Labs and University of Southern California (schools of Cinematic Arts and Engineering). Developed along with Chris Kyriakakis of the USC Viterbi School of Engineering, 10.2 refers to the format's slogan: "Twice as good as 5.1". However, there actually may be 14 discrete channels if the left and right point surround channels are included. He states that 5.1, a name which he himself came up with in 1987, was chosen as it was "the MINIMUM number of channels necessary to give a sense of spaciousness". Holman and others state that higher sampling rates, which is a recent trend in digital recording, does not have a significant perceivable effect and that the next frontier in sound engineering is to increase the number of discrete channels to meet human spatial sound perception. As of 2015^[update], several decoding, UHD, or virtual expansion processors have approached numbers as great or greater than 10.2.

10.2 surround sound would add four more channels to the front listening area and only one surround channel. This is because human spatial perception of sound is much more precise in the front than in the back. In addition it adds depth to the sound field with two of the front channels being height channels, located above the listening area at 45 degrees relative to the listener. Lack of vertical information has long been considered one of the largest obstacles to realistic sound reproduction. Existing systems such as Dolby Pro Logic IIz simulate this with matrixed height channels, which are derived from ambient sounds from the left and right channels.

The ".2" in 10.2 refers to the fact that an additional Low Frequency Effects channel is added, not just a second subwoofer, to enhance the sense of envelopment. All bass from the left channels are directed to a left LFE channel while right channel bass is directed to the right LFE channel.

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