DTS is also a well-known player in surround sound and has adapted its surround sound process for home use. Basic DTS is a 5.1 system just like Dolby Digital 5.1, but since DTS uses less compression in encoding process, many feel that DTS has a better result on the listening end. Also, while Dolby Digital is mainly intended for the Movie Soundtrack experience, DTS is used in the mixing and reproduction of Musical performances.
DTS-ES
DTS has come up with its own 6.1 channel systems, in competition with Dolby Digital EX, referred to as DTS-ES Matrix and DTS-ES 6.1 Discrete. Basically, DTS-ES Matrix can create a center rear channel from existing DTS 5.1 encoded material, while DTS-ES Discrete requires that the software being played already has a DTS-ES Discrete soundtrack. As with Dolby Digital EX, DTS-ES and DTS-ES 6.1 Discrete formats are backwards compatible with 5.1 channel DTS Receivers and DTS encoded DVDs.
DTS Neo:6
In addition to DTS 5.1 and DTS-ES Matrix and Discrete 6.1 channel formats, DTS also offers DTS Neo:6. DTS Neo:6, functions in a similar fashion to Dolby Prologic II and IIx, in that, with receivers and preamps that have DTS Neo:6 decoders, it will extract a 6.1 channel surround field from existing analog two-channel material.
The next step that DTS has taken is to introduce its 11.1 channel Neo:Xformat. DTS Neo:X takes cues already present in either 5.1 or 7.1 channel soundtracks and creates height and wide channels, enabling a more enveloping "3D" sound. To experience the maximum benefit of DTS Neo:X processing, it is best to have 11 speakers, with 11 channels of amplification, and a subwoofer. However, DTS Neo:X can be modified to work with a 9.1 or 9.2 channel configuration.
Surround Sensation creates phantom center, left, right, and surround channels within a two-speaker or stereo headphone setup. It is able to take any 5.1 channel input source and recreate a surround sound experience with just two speakers. In addition, surround sensation can also expand two-channel compressed audio signals (such as MP3) for a more surround-like listening experience.
SRS: Tru-Surround and Tru-Surround XT
SRS Labs is another company that also offers innovative technologies that can enhance the home theater experience.
Tru-Surround has the ability to take multi-channel encoded sources, such as Dolby Digital, and reproduce the surround effect by just using two-speakers. The result is not as impressive as true Dolby Digital 5.1 (the front and side surround effects are impressive, but the rear surround effects fall a litte short, with the sense they are coming from just to rear of your head rather than from the back of the room). However, with many consumers reluctant to fill their room with six or seven loudspeakers, Tru-Surround and Tru-SurroundXT do give the ability to enjoy 5.1 channel sound within a normally-limited two channel listening environment.
SRS Circle Surround and Circle Surround II
Circle Surround, on the other hand, approaches surround sound in a unique way. While Dolby Digital and DTS approach surround sound for a precise directional standpoint (specific sounds emanating from specific speakers), Circle Surround emphasizes sound immersion. To accomplish this, a normal 5.1 audio source is encoded down to two channels, then re-decoded back into 5.1 channels and redistributed back to the 5 speakers (plus subwoofer) in such a way as to create a more immersible sound without loosing the directionality of the original 5.1 channel source material.
The results are more impressive than that of Tru-Surround or Tru-Surround XT.
First, panning sounds such as flying planes, speeding cars, or trains, sound even as they cross the sound stage; often in DD and DTS, panning sounds will "dip" in intensity as they move from one speaker to the next.
Also, rear-to-front and front-to-rear sounds flow smoother as well. Second, environmental sounds, such as thunder, rain, wind, or waves full the sound field much better than in DD or DTS. For example, instead of hearing rain coming from several directions, the points in the soundfield between those directions are filled, thus placing you within the rain storm, not just listening to it.
Circle Surround provides an enhancement of Dolby Digital and similar surround sound source material without degrading the original intent of the surround sound mix.
Circle Surround II takes this concept further by adding an additional rear center channel, thus providing an anchor for sounds emanating from directly behind the listener.
Headphone Surround: Dolby Headphone, SRS Headphone, Yamaha Silent Cinema and Smyth Research.
Surround Sound is not limited to the large-multi channel system, but can also be applied to headphone listening. SRS Labs, Dolby Labs, and Yamaha all have incorporated surround sound technology with the headphone listening environment.
Normally, when listening to audio (either music or movies) the sound seems to originate from within your head, which is unnatural. Dolby Headphone SRS Headphone, Yamaha Silent Cinema, and Smyth Research employ technology that not only gives the listener an enveloping sound, but removes it from within listener's head and places the sound field in the front and side space around the head, which is more like listening to a regular speaker-based surround sound system.
Higher Definition Surround Sound Technologies: Dolby Digital Plus, Dolby TrueHD, and DTS-HD Master Audio
With the introduction of Blu-ray Disc and HD-DVD, in conjunction with the HDMI interface connection, the development of high definition surround sound formats in both DTS (in the form of both DTS-HD and DTS-HD Master Audio) and Dolby Digital (in the form of Dolby Digital Plus and Dolby TrueHD) provides extended accuracy and realism.
The increased storage capacity of Blu-ray and HD-DVD, and wider bandwidth transfer capabilities of HDMI, which is required for accessing Dolby Digital Plus, Dolby TrueHD, and DTS-HD, have allowed for true, discreet, audio reproduction for up to 7.1 Channels of surround sound, while still being backwards compatible with older 5.1 channel surround sound formats and audio/video components.
Note: HD-DVD has been discontinued but is referenced in this article for historical purposes.
Conclusion - For Now...
Today's surround sound experience is the result of decades of evolution. The surround sound experience is now easily accessible, practical, and affordable for the consumer. Go get surrounded!
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