Dolby Pro Logic
The year 1982 Dolby Laboratries Inc. started giving license that allows surround audio system for home devices such as consumption of devices VCR VHS/Beta. Dolby Surround is a trade mark that indicates that the audio system from the audio/video recording has adopted this system. The standard format is Dolby Surrond audio recording encode 4 channel sound (consisting of left, center, right and surround) to 2 channel stereo. Along with that, the system Dolby Pro Logic decoder is adopted by many devices the player to decode the stereo tracks into 2 four channel sound left, right, center and surround. Without the decoder, the format of Dolby Surround sound is like an ordinary stereo quality. Although there is a system equipped with 5 speakers, 2 surround speakers-but his is a single channel mono surround.Dolby Pro Logic II
This system is a further development of Dolby Pro Logic (also known as Dolby Pro Logic I). The difference, Dolby Pro Logic II system can decode 5 channel surround (left, right, center, left surround and right surround) from stereo recordings. Five-channel surround decode can be of 2 channel stereo anything and does not depend on whether the tape was encoded with Dolby Surround format or not. The generated surround sound is stereo surround sound.Dolby Digital 5.1
In the year 1984 Dobly digital encoding developed the standard audio format called channel AC1 (audio coder 1). This format was adopted by some of the penyelengara broadcast satellite tv and cable tv. Then develop the format of the AC2 with better audio quality. Along with the development of digital technology and DSP chip, then developed the Dolby Laboratories Dolby AC3 in 1992 that became the basis of the system surround Dolby Digital 5.1 or Dolby Digital short called (in short DD). This system is also called the first with Dolby SRD (Spectral Recording Digital). Configuration 5.1 has 6 separate sound channel. It was so named because in this audio system there are 5 main Canal (right, center, left surround, right surround, left) and a single channel with the notation IE 0.1 channel called LFE efect (Low Frequency Effect). In practice this effect in the Canal never achieved with a sub-woofer, to visualize sound effect like the sound of bombs, rumbling earthquake and beat feet and so on. But the sense channel LFE is not necessarily the same as the sub-woofer, for a fraction of the information of LFE carrying frequencies low could be divided into right and left surround speakers. Large data rate digital systems the DD is 384 kbps up to 448 kbps 48 KHz sampling with.DTS Digital
The year 1992 was a year of important developments create a DTS System. Then they can convince Steven Spielberg through a demonstration of this format is played from recordings stored on the hard drive. DTS then adopted to Jurasic Park box office. Digital or DTS system in brief DTS also has 6 channel sound with 5.1 format. Same as DD there is the LFE channel carries low-frequency 20 – 80 Hz. Standard data rate was 1.4 Mbps for CD/LD and 1.5 Mbps for DVD with sampling 48 KHz and 24 bits resolution. Indeed the data size larger or DTS standard compressed ratio (12:1 3.5:1 than on DD) is more inefficient than DD, but the argument that has been said by the DTS is the smaller the ratio of compression then the resulting DTS sound will be more natural.SDDS
The system of SDDS (Sony Dynamic Digital Sound) from Sony has a 6 or 8 channel sound (right, left, center, right center, left center, sub woofers, right surround and left surround). Some feature films using the SDDS format especially films production of Sony Entertainment. Reader and decoder specifically for this in the Add movie player on the projector. SDDS formats until recently exclusively only exists for film theaters only and has not been adopted for the home consumer. Of course until now not yet in SDDS-support by many DVD/home theater.THX
THX standard recording format is not a vote, but rather a standard how good audio video system can be generated. THX is certifying quality audio performance at a room. This institution was conceived by Lucas Films and the name of the film THX Lucas first titled ' THX 1138 '. The name of Tomlinson Holman then as technical director of Lucas films, along with his team of the 1980s were the pioneers that set the basis of the standard THX at this time.For the audio system, certification is more aimed at spatial design, insulation, acoustic design, as well as the selection and placement of the audio system. There are two types of certification, the first named THX Ultra for classmates cinepleks room or theater and the second THX Select for small spaces such as the home theater. This certification will certainly add to the production cost of one movie or a device that gets a certificate. But there is a price pinsipnya sure there is quality.