DTS (originally Digital Theater Systems) was founded in 1993 to compete with Dolby Labs for surround sound supremacy. DTS an audio compression technology, allowing movie makers to record surround sound that can be reproduced in cinemas as well as homes, deliver spine-tingling multi-channel sound. DTS is encoded at a higher bit rate and therefore is considered to be better quality. DTS has since released a plethora of more advanced surround sound formats including DTS-HD High Resolution, which supports up to 7.1 speaker channels. DTS has also brought out a lossless format, DTS-HD Master Audio. There's also DTS:X, which competes with Dolby's Atmos

DTS stands for Digital Theater Systems. While Dolby Digitalis the standard 5.1 digital surround format on all DVD players, DTS is becominga possible alternative. DTS, first introduced in the movie JurassicPark,is now found on many film soundtracks. DTS soundtracks have been available onlaserdiscs for the past couple of years, but we're only starting to see DVDtitles with a DTS soundtrack. There are only about a dozen DVD movies with DTSnow, but you can expect this number to grow. And there are quite a few CDtitles that are DTS-encoded, from Mozart to Marvin Gaye. Buying a DVD playerthat's DTS-compatible shouldn't cost all that much more and could mean highersound quality down the road. 'DTS compatible' means that the DVD Player willpass a DTS 5.1 surround sound (audio) signal to a DTS decoder for properplayback of DVDs encoded with a DTS soundtrack.

SPDIF (Sony/Phillips DigitalInterconnect Format) - digital audio interface. SPDIF was first used only totransmit stereo 16-bit PCM data (CD player was the only source of digitalaudio). It is very straightforward: audio samples are transmitted at constantfrequency, one-by-one (and bit-by-bit) in 32-bit blocks where 8 bits are usedfor synchronization and some side info and 24 bits are used for sample. In mostcases, only 16-bit transmission is supported (CD carries only 16-bit sound) andlow 8 bits of a sample are always zeroed. This interface is very simple andcheap and so it became widespread.

Therefore, when multi-channel soundera came to home theaters, SPDIF was an ideal candidate for digital interfaceto transmit multi-channel sound. However, it is a problem: current interfaceimplementations work only with stereo sound, but now it is required to transmitup to 6 channels (or 8 channels at present). It was decided not to change theinterface but to transmit compressed multi-channel sound instead of PCM data(for digital interface it does not matter what to transmit). So receiver mustrecognize compressed data and decode it. For this purpose a new standard wasintroduced (IEC 61937) that describes how compressed data must be transmittedand how receivers can distinguish PCM and compressed data.

PCM data transmission mode and

Unless noted we well use SPDIFtransmission, SPDIF output mode and SPDIF stream terms only for encoded streamsafterwards.

Compressed data may be transmittedover SPDIF instead of PCM data. Therefore, we can prepare a CD disk and placecompressed AC3 or DTS data instead of usual PCM tracks. When we playback thisdisk with a CD player connected to a receiver we will get true multi-channelsound!

DTS CDsare encoded in 5.1 surround sound using the DTS compression algorithm. As such,the fidelity is of lower quality than the sound quality offered by CDs,DVD-Audio discs, and SACDs. DTS CDs are not encoded in stereo. We can play DTSCDs in three ways:

- On a CD playerconnected to a 5.1-channel receiver or pre/pro with a DTS decoder via an optical or coaxial digital cable.
- On a DVD-Video player with the 'DTS Digital Out' logo on the frontpanel (meaning any player available today) to a 5.1-channel receiver or pre/prowith a DTS decoder via an optical or coaxial digital cable.

SONY DVD COMBO Players: