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dolby digital (DD)

Dolby is generally understood to mean the Dolby Digital(DD+) compression process. This process, formerly called AC-3, allows six- channel sound reproduction, called DD-5.1, with up to five full-range channels and one LFE (Low Frequency Effect) channel for low- frequency effects creating surround sound.

The full-range channels are for the front speakers - left, center, and right - and for the two surround speakers in the back, left and right, which provide realistic surround effects. The frequency range of these speaker cabinets is between 20 Hz to 20 kHz. The subwoofer's low bass channel has a reduced bandwidth at low frequencies.

Specifications of Dolby Digital

Specifications of Dolby Digital

Dolby Digital (DD) is used in DVD-Audio and is one of the most important audio file formats, along with MPEG and pulse code modulation( PCM). It operates at coding rates of 384 kbit/s to 640 kbit/s.

In addition to Dolby Digital, Dolby Laboratories has set many standards in soundsystems. For example, for noise reduction.

Dolby Digital knows several different modes, which one recognizes by the version indication. The information behind the point means whether there is a separate channel for the subwoofer.

DolbyDigital 1.0: single-channel mono playback via the center speaker

Dolby-Digital2.0: two-channel stereo playback via the right and left speakers.

DolbyDigital 4.0: Multi-channel combined stereo/mono playback for Dolby Surround via the front right and left speakers in stereo, from the center and rear speakers in mono.

Dolby Digital 5.0: Multi-channel stereo playback using all five speakers except the subwoofer.

Specifications of Dolby Digital for DVD, DVD-Audio, Blu-Ray and HD-DVD

Specifications of Dolby Digital for DVD, DVD-Audio, Blu-Ray and HD-DVD

Dolby Digital 5.1 (DD-5.1): Multi-channel stereo playback with full-range channels and a bass channel transmitted as Low Frequency Enhancement (LFE) in MPEG-2. The frequency range for the bass channel is between 3 Hz and 120 Hz. DD-5.1 has the following speaker arrangement: front left, front center, front right, rear left, rear right, and subwoofer.

Dolby Digital Plus (DD+) is a lossy audio compression that is mandatory in HD-DVD and Blu-Ray disc.

Speaker arrangement of Dolby Digital 5.1

Speaker arrangement of Dolby Digital 5.1

Dolby-Digital EX: This is a 6.1 channel system where a rear center channel( SRC) is added to the 5.1 channel system. This center channel covers the same frequency range as the front channels. Its signal is housed as a matrix in the signals of the two surround channels. 6.1 has an even more realistic sound image compared to 5.1. Dolby Digital EX is the home version of Dolby Digital Surround EX. In addition to these versions, there is also Dolby Surround as a multi-channel technology.

The extension for Dolby Digital files is *.dts.

Englisch: dolby digital - DD
Updated at: 03.12.2012
#Words: 407
Links: dolby digital plus (audio codec) (DD+), compression, process, audio code number 3 (AC-3), channel
Translations: DE

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