What is the different between DTS/ AC3/ Dolby ?

Answer 1

The first link below provides an excellent, detailed overview. Links to the home sites for Dolby, DTS and SDDS (See below) are also provided.

More basically, there are three competing multi-channel digital sound formats used for films today: Dolby Digital, DTS Digital Sound and SDDS (Sony Dynamic Digital Sound). The latter is not used in North America. Note that Dolby (actually Dolby Laboratories) is the name of the company that originated the Dolby Digital format. AC-3 (Audio Coder 3) is an early Dolby Digital form and is still the core of the Dolby Digital system.

Dolby Digital and DTS each have advantages and disadvantages, but practically speaking they provide equivalent psychoacoustic results. Because of the way they work all three can be used on a single film print (although technically DTS sound is not encoded directly on the film print, but on a separate CD and synced with the film via time codes) ... which is why the credits for films often list all three. DVDs almost always have Dolby Digital encoding (the DVD standard requires either a Dolby Digital or PCM (uncompressed) audio track) and MAY also have DTS.

Note that Dolby Digital is not automatically 5.1 sound, but may be mono, stereo, or quadraphonic.

Hope this helps clarify.

Answer 2

I believe DTS uses less compression than Dolby Digital, and it also has a wider dynamic range (soft to loud). DTS is considered the better of the two. Look for music DVDs and you'll find the better ones have a DTS track, like the Eagles Hell Freezes Over DVD, it's considered one of the best recordings out there in DTS.