By Jack Sharkey, September 16, 2015.
On May 12,1967, Pink Floyd played a show in London with a “surround-sound” system. I get the psycho-acoustic (and psycho-trophic) desire, especially for a band like Pink Floyd, to tinker around with surround sound at a live show, but live-surround sound always seemed a bit of an oxymoron to me. Hats off to technological advance and experimentation though.
In the early 1970s, music studios dabbled with quadraphonic recording, and for home use, quad had promise but there were some serious technical obstacles to overcome – and the technology of the day simply wasn’t advanced enough. Open-reel tapes were available in true discrete quadraphonic sound, but the machines were expensive and therefore broad appeal was light. Vinyl posed a serious roadblock to true discrete quad sound so the two “rear” channels were mixed via a matrix to be decoded by the receiver. This solution was also expensive with little mass appeal.
You could win a bar bet by knowing that quadraphonic sound (surround-sound as we call it now) first became available in 1969. In 1970, RCA Records released Quad-8 tapes which were 8-Track tapes that played discrete quadraphonic sound. If you played them on a standard stereo 8-Track you would only get half the sound, so this lack of backward compatibility meant you had to buy a specific Quad-8 player. Again, expensive with not a lot of demand. Quad-8 tapes were available until 1978, but demand was never strong.
Since there were no viable ways for the mass consumer to play movies at home, surround-sound was specifically a music term. Keep in mind, when VCRs first became broadly available in the late 1970s, the people (mainly the movie making people and the movie theater owning people) were up in arms about lost revenue and licensing, so there was a lot of pushback on the ability of the Average Joe and Josephine to own movies in their own homes. Funny how that worked out.
So with that genesis in mind, let’s take a look at the history of surround sound formats and the nomenclature that at times seems specifically designed to confuse us all.
1941: Fantasia is released by Disney Pictures. Walt Disney challenged his engineering team to come up with a way for the music in the film to envelope and surround the listener, (engineers at Bell Labs were already working on a multiple-microphone recording system). Disney’s proprietary Fantasound system is considered the first cinematic use of surround technology with sound emanating from the left-, center-, and right-front and the left- and right-rear positions. The two rear channels were played back from a separate reel of film and because of the additional equipment needed (54 speakers plus the additional playback machines), only two theaters (one in New York and one on Los Angeles) laid out the $85,000 necessary for the system.
1954: Electronic music studios in Europe begin using Q4: Standard 4-Track tapes with all four tracks recorded simultaneously to produce a mix that could be played back by four discrete speakers giving the listener the sensation of space and of being surrounded by sound.
1967: Pink Floyd plays the first-ever concert in full quadraphonic sound in London. The system comprised four discrete channels placed in the four corners of the concert hall, theoretically enabling the audience to listen from the center of the sound source.
1969: Vanguard releases Q4 on open-reel tapes to the American market. Surround-sound is known as quadraphonic and is primarily a music technology.
1976: Dolby develops analog surround systems for cinema use. Coincidentally, 1976 is also the year that saw the demise of the Quad-8 format commercially, although RCA would continue to issue Quad-8 material until 1978.
1977: JVC introduces the VHS tape at the Chicago CES show. It would be a few years before this format beat out rival Sony’s Betamax which was developed in 1975.
1982: Dolby Laboratories introduces Dolby Surround, which uses a matrix encoding to “piggy-back” the program for the rear speakers on to the signal for the left and right front speakers. Due to the limited bandwidth available on VHS tape, the center channel is a composite of the left and right signals panned to the center and the rear channels are the negative sum (phase reversed) from the front channels.
1983: Pioneer Electronics introduces the Laserdisc. Storage space was greatly increased over VHS allowing for more channels and greater bandwidth. Dolby Labs exploited this by introducing AC-3 (Dolby Digital) which featured stereo rear channels, enhanced bandwidth and a separate Low Frequency Effects (LFE) channel allowing for the addition of a subwoofer. This is the beginning of the “5.1” system – five channels (2 front, 1 center, 2 rear) with the “.1” signifying the subwoofer. Thirty-two years later, Dolby Surround is still considered a benchmark technology and is still included on most contemporary Blu-Ray disks.
1987: Dolby introduces Pro-Logic which used two extra channels of audio information for the rear and center channels. Because of space and bandwidth limitations, the rear speakers were monaural and both the rear and center channels had limited frequency response.
1992: Batman Returns is released in Dolby Digital.
1993: Calabasas, California-based Digital Theater Systems introduces DTS as a rival format to Dolby. For theatrical releases, Dolby Digital’s audio information is located between the sprocket holes of the film and is a slightly lower bitrate than DTS, which uses a time-code optically imaged onto the film that is read and synched to a CD-ROM that carries the audio information. DTS is generally considered to be of a higher fidelity than Dolby.
1993: Steven Spielberg releases the first DTS encoded movie, Jurassic Park.
KEF KHT2005.1 Surround System (L)
1995: The DVD is introduced. Developed by Phillips, Toshiba, Matsushita (Panasonic) and Sony, the storage capability of the DVD paves the way for more intricate sound programs and eventually mainstream High Definition television.
1999: Dolby introduces Dolby Digital EX, a 6.1 surround format. The format never really takes hold, likely because most consumers (incorrectly) view the two surround speakers as “rear” channel (they are supposed to be set-up slightly behind, and to the side, of the listener). In a 6.1 system, the sixth speaker is truly a rear speaker. Also, the advent of 7.1 (center, two front, two rear, two side speakers) pretty much negated the desirability of 6.1.
2006: The Blu-Ray is introduced and along with it, 7.1 surround, which adds side channels to the mix. In spite of the mega-storage (giga?) capabilities on a Blu-Ray disk, 7.1 is still not widely available because of the amount of disc storage space the program takes up (content producers tend to choose to release more "extras" on disks which reduces the amount of storage space available for audio). Dolby and DTS have 7.1 formats in both lossy (compressed) formats and uncompressed formats.
2014: Dolby introduces Atmos to the general consumer. Atmos adds a third dimension – height – to the soundscape of a movie. Initial general consumer Atmos-enabled units can support up to four Atmos speakers for a 5.1.4 or 7.1.4 system. Theoretically, an Atmos-encoded program can contain up to 128 channels arrayed as 3-D compass points.
There are a few subsets to Dolby and DTS encoding, but this piece is meant to be a general introduction to some of the technology and terminology of surround sound. Hopefully this will help clear up some of the mystery so you can get to the business of enjoying the art.
The opinions expressed in this article are the author's own and not necessarily those of KEF or its employees.