DTS digital surround is said to be the best surround sound format available. This page details the format, describes its history, and compares DTS to other sound formats used in home cinema.
INTRODUCTION
MONO
STEREO
QUAD
DOLBY STEREO
DOLBY SURROUND
DOLBY PRO-LOGIC
DOLBY DIGITAL
DOLBY DIGITAL-EX
DTS
DTS-ES
MPEG-II
SONY SDDS
THX
TIMELINE

Sound Formats

 

DTS  
   

DIGITAL THEATER SYSTEMS (DTS)

The DTS format began to be used in the cinema in 1995. It was created as a 5.1 channel digital surround sound format to rival the dominant Dolby Digital. DTS differs from Dolby Digital in the way that the digital data is compressed during encoding. Dolby Digital compresses the original sound by about 12:1 during encoding, while DTS uses a variable compression ratio of between 1:1 and 40:1 depending on the amount of information contained within the soundtrack at any given time. This compression on DTS soundtracks potentially allows more of the original signal to be retained and, on paper, is capable of producing sound clearer and faster than Dolby Digital. In reality, both systems are the state of the art in cinema sound systems, and only long, repeated listening sessions are likely to expose any differences.

 
   
DTS sound in the cinema is well established, but DTS home cinema software is a little harder to come by. First used in the home cinema world on the 1996 Laserdisc release of Jurassic Park, DTS encoded Laserdiscs are quite common - but only on imported NTSC format discs. Additionally, due to the fact that DTS uses less audio compression resulting in the need for greater storage space on the disc in which to encode the sound data, no other stereo or analogue soundtracks can be added to Laserdisc, unlike Dolby Digital discs. This is to be rectified with DVD video, where the extra storage space available would allow a DTS soundtrack plus another sound format for those without the necessary DTS decoder. DTS on DVD Video discs is happening in the USA and Japan, and is slowly filtering into the UK. The downside to this is that you need a DVD player that can read DTS soundtracks. This is not a problem for new players as they can all read and output a DTS data stream. The main reason for this special type of output is the way in which DTS is encoded onto discs. CD and Laserdisc store DTS soundtracks as a PCM signal the same as stereo audio and can, therefore, be transferred using a standard digital cable. The PCM signal is split by the decoder into the multi-channel sound. On DVD, the DTS track is stored as a Bitstream and requires a dedicated type of output to send the signal to the decoder.  
   
DTS 5.1 Digital Surround
Two main speakers, two rear surround speakers, a front centre speaker and a dedicated subwoofer channel
   
DTS Stereo 2.0
Two main front channels of stereo audio. As with Dolby Surround, audio information for a centre and rear surround channel can be matrixed with the stereo channels for playback on Dolby Pro-Logic equipment
   
DTS Mono 1.0
Single discrete mono audio channel heard through the centre speaker, or through two front speakers as a mono soundtrack where no centre speaker is present