GLOSSARY
■Encode/Decode
When a signal or other information is processed, compressed and digitized, this is called encoding. Encoding can be used to record an extremely large amount of information on a single CD or DVD.
An encoded signal cannot be listened to directly. It must be returned to its original state (i.e. audible sound) and this is called decoding.
■Sound field
Not all sound travels from the sound source directly into the human ear, but instead reflects off of walls, ceilings and other objects to arrive at the ear slightly delayed (early reflection). It may also reflect repeatedly in a complicated manner before reaching the ear (subsequent reverberation). A human is able to perceive the size and shape of a location based on the various sounds heard in this way. The specific acoustic space of a particular building is called a sound field.
■Dolby Surround
In movie theaters and in live theaters, the spectators are surrounded by many speakers and sound effects geared to each scene are used to make sound move from front to back and right to left. This gives the sound a three dimensional feel that surrounds the entire body. Dolby Surround is used to implement this realistic effect. Originally, the Dolby Surround system consisted of a total of four channels: two front channels (right and left), one center channel, and one rear channel. Later,
■Dolby Pro Logic II
Dolby Pro Logic II is an improved technique used to decode vast numbers of existing Dolby Surround software. This new technology enables a discrete 5- channel playback with 2 front channels, 1 center channel, and 2 rear channels (instead of only 1 rear channel for conventional Pro Logic technology). A music mode is also available for
■Dolby Digital
Dolby Digital consists of a total of five channels: three front channels (left, center and right) and two rear channels (right and left), plus a distinct LFE channel for low frequency effect. It is therefore commonly referred to as a 5.1 channel system. Using digital compression technology for all 5.1 channels, Dolby Digital can be used for completely independent audio reproduction. Dolby Digital offers superior sound separation between each channels and a more three dimensional surround effect in comparison to the older Dolby Surround, which mixes four channels (three front and one rear) into
■DTS (Digital Theater Systems)
Digital Surround
DTS was developed to replace the analog soundtracks of movies with six discrete channels of digital soundtracks, and it is now installed in many theaters around the world. The DTS digital playback system changed the way we experienced movies in theaters with six discrete channels of superb digital audio.
DTS technology, through intense research and development has made it possible to deliver similar encode/decode discrete technology to home audio
DTS Digital Surround is an encode/decode system which delivers six channels of
■LFE 0.1 channel
This channel is for the reproduction of low bass signals. The frequency range for this channel is 20 Hz to 120 Hz. This channel is counted as 0.1 because it only enforces a low frequency range compared to the
■SILENT CINEMA
YAMAHA has developed a natural, realistic sound effect DSP algorithm for headphones.
Parameters for headphones have been set for each surround mode so that accurate representations of all the surround modes can be enjoyed using headphones.
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