Surround Sound Processing

(How many speakers do we really need?)

Why surround?

• Ever since the 1950’s, great steps have been taken in order to create the ultimate home-entertainment experience.

• Walt Disney attempted to create a surrounding sound experience with the viewing of Fantasia. The surround sound process was called “Fantasound”

Monophonic

• Single source of sound– Usually, a TV speaker or a radio transmission– This source is referred to as a “channel”

Monophonic

Stereo

Dual source of sound– Involves the use of two speakers, or

“channels,” paired as a Left and Right

– Dubbed as “Hi-Fidelity”

– In Dolby, this is considered AC-1, because one track carries both channels

Stereo (1970’s)

Quadraphonic Stereo(1970’s)

Dolby Surround(1985’s)

• Two (2) audio tracks are used: Left and Right (track 1), and Mono Surround (track 2)

• These two tracks are carried on stereo program sources such as videotapes and TV broadcasts into the home

• This was dubbed as “AC-2”, because two tracks were used to carry three channels of sound.

(http://www.dolby.com)

Dolby Surround(1985)

Dolby Pro-Logic Surround(1989)

• Like Dolby Surround, Dolby Pro-Logic Surround used the original two tracks of audio – Left and Right (track 1) and Mono Surround (track 2) – while adding a third track for the Center channel (track 3)

• This new track was used with a filter system that generated all “direct front” sound (such as actor’s voices) to appear as though it was centered (hence, the “center channel”

Dolby Pro-Logic Surround(1989)

Dolby 5.1 Digital Surround(1995)

• The speaker arrangement uses six channels (only available on DVD and Blue-Ray): Left, Right, Center, Surround Left, Surround Right, and the Low-Frequency Channel (subwoofer).

• Dolby 5.1 Surround is dubbed so because the .1 LFE (subwoofer) channel is not a constant sound generator. It is actually triggered, on occasion, to fire.

• This Dolby technology truly uses separate stereo surround signals, versus the original mono channels available in Dolby Surround and Dolby Pro-Logic. (AC-3)

Dolby 5.1 Digital Surround(1995)

Dolby EX (THX) Surround(2002)

• Dolby Digital EX takes the Dolby Digital 5.1-channel setup one step further with an additional center surround channel (reproduced through one or two speakers) for extra dimensional detail and an enveloping surround sound effect.

• Feature films originally released in Dolby Digital Surround EX (the cinema version) carry the encoded extra surround channel in their subsequent DVD releases, as well as onto 5.1-channel digital satellite and TV broadcasts.

• Also known commercially as THX

Dolby EX (7.1) Surround(2004)

Dolby Digital Plus

• Dolby® Digital Plus is the next-generation audio technology for all high-definition programming and media.

• Can deliver 7.1 channels and beyond* of enhanced-quality audio

• Allows multiple languages

• Compatible with the millions of home entertainment

systems equipped with Dolby Digital

Ray Dolby

• Received a B.S. in electrical engineering from Stanford University in 1957 and a Ph.D. in physics from Cambridge University

in 1961

• Ray Dolby has been inducted into the National Inventors Hall of Fame in recognition of his invention of Dolby noise reduction

Ray Dolby

• Founded Dolby Laboratories in 1965 to further develop his ideas

about noise reduction

Patrons of Dolby Surround

Pioneer ElectronicsPioneer Electronics Kenwood ElectronicsKenwood Electronics

JVCJVC

Creative LabsCreative Labs

AkaiAkai

SamsungSamsung

AvidAvid

LGLG

ClarionClarion

EclipseEclipse

Sony CorporationSony Corporation

RCARCA

OnkyoOnkyo

AiwaAiwa

SanyoSanyo

M-AudioM-Audio

AlpineAlpine

Consumers of Dolby Surround

• Audiophiles and Media enthusiasts were the original target audience for the Dolby Processing system.

• After the Home-Entertainment Industry really finally took off, every consumer in the general public became the target market of Dolby

Laboratories. Rarely, can there be found any piece of home entertainment equipment without the Dolby logo

emblazoned on it.

Producers of Dolby Surround

Manufacturers of Home Entertainment equipment are not the only prospects of Dolby Laboratories. Movie and Television production companies are Dolby’s greatest advocates, investing millions of dollars per production in the audio processing alone.

Every audio cassette, CD-Rom, VHS cassette, DVD-Rom, and Blue-Ray Disk are encoded using some form of Dolby processing.

Meeting the Needs and Wants

Recreating a true-to-life environment, even in a surrealistic one that Hollywood can conjure up, is the ambition of every entertainer, director, and producer. When not only the sights but the sounds help to establish the make-believe world as a viable option for escapism, then the needs and wants of consumers have been met. And, if the needs and wants of the consumers have been met, then the needs and wants of those in the production of audio and video have been met.

Today, the newest benefactors of this technology are those who dwell in the video game arena, with just about every game in the market produced in multi-channel surround mode. Gamers everywhere can thank Super Nintendo and the 1994 game “Jurassic Park” – the first video game ever to be produced in Dolby Surround Sound.

The Trade-offs

With the more dynamic the audio system, the more complex it becomes to set it up, and the more expensive it is to get things going. Multi-Channel surround systems, whether Dolby, DTS (Digital Theater System) and THX, the more speakers there are, the more the system costs. And, because the idea of going “digital” is such a big deal, the sound systems and their peripherals can cost an arm and a leg. Thankfully, consumer grade equipment is quite manageable.

Home Theater Systems are not unlike Computer systems, in that they seem like a never-ending arms race of the biggest and baddest of technologies. Upgrading and maintenance are constantly on the minds of uber-audiophiles and entertainment enthusiasts who just have to have the best.

Citations

•Dolby Technologies: Dolby.com

•About.com: The History And Basics Of Surround Sound - Dolby Surround

•Broadcasterbuyer.com: Ray Dolby Inducted Into The National Inventors Hall Of Fame

•Atlantic Technology Timeline