Surround Sound Formats
Surround sound uses multiple audio tracks to draw the movie-watching audience in as if they were a part of the action. Surround sound allows the listener to hear sounds coming from all around them and plays a large part in the movie world. There are different sound formats that are encoded on DVDs or ones that are used in your new home theater system. The formats below are considered true surround sound because they rely on multiple dedicated speakers.
Dolby Digital surround is an advanced form of digital audio coding and refers to a surround sound system that employs discrete digital recordings. Dolby Digital is available on DVDs, DVD-ROM discs, digital cable system and digital broadcast systems. Not only is it used with standard definition DVD discs, it is also being used as a part of the new HDTV standard. The term “Dolby Digital surround” is most often used when describing a 5.1 Channel audio system. With the six-discrete channels, sound can be heard precisely and with improved dialogue clarity.
Dolby Pro Logic was designed to decode soundtracks encoded with Dolby Surround. It is standard for analog television broadcasts, since the signal can be encoded in a stereo analog signal. You can still enjoy movies even if you have an older receiver, since all DVD players convert Dolby Digital information to the Pro Logic format.
DTS Digital Surround:
An alternative to the Dolby Digital format is DTS Digital Surround, which uses less compression than Dolby Digital. Many audiophiles believe that it produces a rich bass with greater dynamics that are more accurate than Dolby Digital. Just like Dolby Digital, it is a 5.1 Channel surround sound format and is an optional soundtrack on some DVD movies. The main advantage of DTS is that it offers higher data rates that may improve the sound quality. Although sound reproduction may be enhanced, fewer DVDs are encoded with DTS as compared to Dolby Digital.
DTS-ES (Digital Theater Surround – Extended Surround) Discrete is a 6.1 channel system that provides more sound effects than a standard 5.1 surround sound system. It requires a receiver with ES Processing, which enables you to add one (or two) rear center surround channel speaker(s) to the 5.1 channel surround. An ES processor will recognize the discrete sixth channel and play it back if connected to the correct speaker. In a 7.1 channel configuration, the two rear-center speakers play in mono. Currently, there are only a few ES-encoded DVD’s, so to utilize this format an ES-capable receiver is required.
Dolby TrueHD is an advanced multi-channel audio code that is primarily used for high-definition home entertainment equipment such as Blu-Ray and HD DVD players. It will allow you to experience high-definition surround sound by delivering audio that is identical to the master recording. TrueHD delivers 5.1 or 7.1 channel surround sound with 100% lossless coding, which is when the original data is reconstructed from the compressed data.