Audio Types

This page is for listing the various audio types and defining them as a community.

The page is sorted by company, and then technology.

Please assist by growing this page by providing information that is missing.

Dolby Laboratories

Dolby Laboratories, Inc. is an audio technology company originally founded in London, England in 1965 by Ray Dolby. It's headquarters are currently at Civic Center, San Francisco, California, USA and operate as a global brand.

Dolby Laboratories are known for their advances in noise reducation and audio encoding technology for pre-recorded music and consumer film releases.


Dolby Digital

Formats: LaserDisc, DVD, Blu-ray, HD DVD
Also Known As: Dolby Stereo Digital, DD (Short for Dolby Digital), AC-3, ATSC A/52
Year of Introduction: 1992
Bit-rate: 320 kbits/s (Constant)
Sample-rate: >48 kHz
Audio Codec: Dolby AC-3
Max Channels: 5.1 (6 Channels)

Maybe the most popular audio encoding technology present on video releases, Dolby Digital is a digital lossy audio compression method used in a wide variety of applications including cinema theaters, home video, TV broadcast and video games.

The first film to use Dolby Digital was Batman Returns (1992, Tim Burton) and was available when the film premiered in theaters. For cinema the Dolby Digital audio track is optically recorded onto the 35mm release print. An analogue Dolby Stereo track is also usually present on Dolby Digital cinema releases which features Dolby's SR noise reduction technology.

The Dolby Digital technology supports up to 6 audio channels, which when all channels are used work in the following layout:

  • 1x Right Channel (20Hz - 20,000 Hz)
  • 1x Center Channel (20Hz - 20,000 Hz)
  • 1x Left Channel (20Hz - 20,000 Hz)
  • 1x Right Surround Channel (20Hz - 20,000 Hz)
  • 1x Left Surround Channel (20Hz - 20,000 Hz)
  • 1x Subwoofer Channel (20Hz - 120 Hz)

The first home release to use a Dolby Digital mix was the 1995 Laserdisc release of Clear and Present Danger 1994, Phillip Noyce.

Logos:

Dolby Digital
Dolby Digital

Current Dolby Digital Logo

Dolby Digital
Dolby Digital

Old Dolby Digital Logo

Further Reading:
Wikiepdia


Dolby Digital EX

Formats: DVD
Year of Introduction: 2001 (?)
Bit-rate: 320 kbits/s (Constant)
Sample-rate: >48 kHz
Audio Codec: Dolby AC-3
Max Channels: 7.1

Dolby Digital EX is the consumer technology version of Dolby Digital Surround EX (a cinema only technology). This technology, an extension (the reason for the "EX" in the name) of Dolby Digital, introduces an additional rear surround channel.

According to the Dolby website any film released in the cinema with the Dolby Digital Surround EX technology will carry the Dolby Digital EX format forward into any subsequent DVD releases, allowing consumers to experience 6.1/7.1 surround on their home theater systems (if supported by the equipment). Releases prior to 2001 may require the consumer to set their home theatre equipment to manually decode the Dolby Digital EX audio track, unlocking all audio channels.

Logo:

Dolby Digital EX
Dolby Digital EX

Further Reading:
Wikipedia
Dolby Website


Dolby Digital Surround EX

Formats: 35mm
Year of Introduction: ?
Bit-rate: 320 kbits/s (Constant)
Sample-rate: >48 kHz
Audio Codec: Dolby AC-3
Max Channels: 7.1

Dolby Digital Surround EX is a technology only found in cinema theaters. Consumers will be able to experience Dolby Digital Surround EX on their home video releases that feature the Dolby Digital EX technology.

The first film to use Dolby Digital Surround EX was Star Wars: Episode I – The Phantom Menace (1999, George Lucas).

Logo:

Dolby Digital Surround EX
Dolby Digital Surround EX

Further Reading:

Wikipedia
Dolby Website


Dolby Digital Plus

Formats: HD-DVD, Blu-Ray
Also Known As: Enhanced AC-3, DD+, E-AC-3, EC-3
Bit-rate: 6114 kbits/s (Constant)
Audio Codec: Dolby E-AC-3
Sample-rate: >48 kHz
Max Channels: 13.1

Dolby Digital Plus is a successor to the popular Dolby Digital format. It introduces a selection of improvements on the original Dolby Digital technology including a higher bit-rate, more audio channels, multi-program support and additional tools for representing the compressed data. The use of the Dolby E-AC-3 codec allows Dolby Digital Plus to include 15 audio channels running at full-bandwith use reaching a maximum bit rate of 6.144 Mbit/s.

For consumer grade applications, Dolby Digital Plus is possible on the HD-DVD and Blu-Ray video formats. For HD-DVD Dolby Digital Plus is a mandatory component, however it is only optional for Blu-Ray releases. Due to the contraints of the formats, only 7.1 channels can be achieved when using Dolby Digital Plus.

Logo:

Dolby Digital Plus
Dolby Digital Plus

Further Reading:
Wikipedia
Dolby Website


Dolby TrueHD

Formats: HD-DVD
Bit-rate: 320 kbits/s (Constant)
Audio Codec: Dolby AC-3
Max Channels: 5.1

Further Reading:
Wikipedia


dts (Dedicated to Sound)


DTS 70mm

DTS-ES

DTS Neo:6

DTS Neo:X

DTS 96/24

DTS-HD High Resolution Audio

DTS-HD Master Audio

DTS:X

No Company

Hi-Fi Audio

Stereo

Mono