quadraphonic

Quadraphonic was an early attempt at surround sound using four speakers in the very late 1960s and 1970s. Thousands of recordings were made in quadraphonic, but it was not a commercial success, partly due to the number of competing formats.

Dynaquad (1970 – 1976)

In 1969, Dynaco introduced a system to ‘derive’ surround sound from stereophonic LPs by using a passive electronic circuit called a Hafler Circuit. This was designed by Dave Hafler of Dynaco in the early 1960s and required four speakers in a diamond configuration for derived quadraphonic (2:2:4) sound.

Around 1970, Dynaco introduced the Dynaquad system for encoding matrixed quadraphonic sound (4:2:4). The system was similar to EV Stereo-4 (EV-4) introduced in 1970, and was broadly compatible.

A sampler disc for the Dynaquad system was released in 1971 on the Vanguard Records label, and by this time it was suggested that the four speakers were placed in the four corners of the room rather than the diamond configuration.

Very few records appear to have used Dynaquad encoding. The 1970 eponymous album by The Flame may have used Dynaquad, along with some of the ‘Environments’ series by Syntonic Research. There were also some LPs and 7-inch singles produced by KL Recordings in the mid-1970s.

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Quadraphonic 7-inch single (1971 – 1976)

Quadraphonic recording was a means of providing sound from four channels, and on vinyl records was most often used on 12-inch long-play (LP) records. It was not a commercial success partly due to a number of competing systems.

Quadraphonic sound on 7-inch singles was even less common. As well as 7-inch singles playing at 45 rpm, there were also some quadraphonic EPs and Little LPs, which played at 33⅓ rpm. Many of the EPs and Little LPs seem to have been produced for use in quadraphonic jukeboxes.

Nearly all quadraphonic releases on 7-inch records used either the SQ Quadraphonic or Quadraphonic Sound (QS) systems.

Quadraphonic singles were introduced in 1971, and releases seem to have peaked around 1974. In 1976, releases appear to have ceased, a few years ahead of quadraphonic LPs.

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Quadraphonic Compact Disc (1982 – early 1990s)

The Norrie Paramor Orchestra: Temptation (1986) (QS quadraphonic mix from 1978)
The Norrie Paramor Orchestra: Temptation (1986) (QS quadraphonic mix from 1978)

In the early days of Compact Disc, a number of discs were mastered using an existing quadraphonic mix. Where a matrixed quadraphonic mix was used to master the Compact Disc, this inadvertently resulted in a Compact Disc that can be played back through a suitable decoder to reproduce quadraphonic sound.

Quadraphonic releases were more common in the 1970s, but quadraphonic wasn’t a commercial success, partly due to the number of competing standards and also because to listen to quadraphonic sound required a suitable decoder as well as additional speakers. Despite this, some music was only ever mixed for quadraphonic sound, and so was the only mix available when it came to first releasing an album on Compact Disc.

Matrixed quadraphonic formats that were used for LP records, such as QS, SQ and EV Stereo-4, can be successfully decoded from Compact Disc since matrixed recordings encode and decode 4-channels of audio information in a 2-channel medium. Because of this, a number of early Compact Disc releases contain quadraphonic sound, though this is only occasionally mentioned on the disc or the cover.

Four-channel Compact Disc recordings were contemplated, and this is briefly mentioned in the Red Book specification of 1980 as well as later editions, but was not fully specified. No mass-market Compact Discs have used more than two-channels.

More recently, surround sound has been available through formats such as Super Audio CD (SACD), DVD-Audio and High Fidelity Pure Audio (Blu-ray).

Figures

Dimensions: 120 mm × 1.2 mm

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Matrix H (1977 – 1978)

Matrix H was a matrix quadraphonic audio system devised by the BBC in the mid-1970s and first used in 1977. It was one of a number of systems tested by the BBC, lettered from A to H.

One of the requirements was that it must be compatible with mono and suitable for radio transmission via FM.

Some radio programmes were broadcast in Matrix H, including live broadcasts from the 1977 BBC Proms and some session recordings by bands on Radio 1. This was despite very few people having access to decoders, so some public demonstrations were held. The experimental radio broadcasts lasted until 1978.

No recorded music was officially released, but a handful of 12-inch LPs were released that did use Matrix H but were labelled as stereo.

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EV Stereo-4 (1970 – 1975)

The EV Stereo-4 system (also known as EV-4) was a matrix quadraphonic format, developed by Leonard Feldman and Jon Fixler in 1970 and taken up by Electro-Voice as the first commercial quadraphonic system for vinyl records.

A handful of record labels used the system, including Ovation, Project 3 and Quad-Spectrum, and RadioShack sold compatible decoders and systems in the US.

EV Stereo-4 emphasises front (left to right) and front-to-rear separation, but there is less separation between the two rear channels.

In 1973 Electro-Voice introduced a decoder that could also play SQ and QS quadraphonic records with good results, but despite this Stereo-4 was pushed out of the market by these other systems and nothing appears to have been released on EV Stereo-4 after 1975.

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SQ Quadraphonic (1971 – 1982)

SQ Quadraphonic (from ‘Stereo Quadraphonic’) was a system for providing quadraphonic sound from four speakers on vinyl records. It was introduced by CBS Records in 1971, and was adopted by a number of other record companies including EMI and Sony.

It was a matrix format, so the four channels were encoded into the stereo grooves of a 12-inch LP and then decoded back to four channels. As the grooves were slightly broader than a standard LP, playing time on an SQ record was reduced.

Of the different quadraphonic systems for vinyl, SQ has the largest discography and this was partly because SQ records were fully compatible with stereo equipment. Some early Compact Discs used the SQ mix.

Consumers needed to buy an SQ decoder to take advantage of quadraphonic sound, but early versions provided poor separation. The sound separation of the SQ system was greatly improved by the introduction of SQ Full Logic decoding in 1975, but by this time all quadraphonic systems were declining in popularity and by the end of the 1970s, only small numbers of SQ Quadraphonic LP titles were being released.

The final releases were on the Supraphon label in 1982.

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Quadraphonic Sound (QS) (1971 – 1978)

Quadraphonic Sound (QS) was developed at Sansui and introduced in 1971. It is a matrix format for quadraphonic sounds from the 12-inch LP vinyl record. It was also referred to as Regular Matrix (RM).

The format was freely licensed to record companies, and was used by a number of them. It offered excellent diagonal separation and was compatible with stereo systems.

Some systems were compatible with both QS and SQ formats, and QS was compatible with the original EV format, and can synthesise quadraphonic sound from standard stereo records.

The tracks on the QS vinyl LP are the same width as standard stereo tracks, so playing time is the same as conventional 12-inch LPs.

The last adverts for QS systems appeared in 1978.

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CD-4 (Compatible Discrete 4) / Quadradisc (1972 – 1979)

Compatible Discrete 4 (CD-4) or Quadradisc was a 12-inch LP format created by JVC and RCA and introduced in 1972.

It was the only fully discrete quadraphonic phonograph record system to gain major industry acceptance.

In the CD-4 system, each of the two main channels contained the sum of the front and back signals. A separate carrier was recorded onto each groove wall that contained the difference signal for that side. From this, the combined  signals for each side could be resolved into two separate signals, creating discrete quadraphonic playback. CD-4 LPs could be played on stereo turntables,

The grooves on a CD-4 record are broader than on conventional stereo LPs, so the maximum playing time is reduced, and it was recommended that consumers play CD-4 records with a cartridge with a special ‘Shibata’ stylus, which increased the surface area of the stylus, thus decreasing the pressure on the grooves.

Most of the CD-4 releases by RCA were in the period between 1972 and 1975, with only 11 releases in 1976 and the last release in 1979.

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Quadraphonic 8-Track (Q8) (1970 – 1978)

Quadraphonic 8-Track (also know as Quad-8 or Q8) was a discrete 4-channel magnetic tape cartridge system introduced by RCA Records in 1970.

It was based on the 8-Track cartridge, and cartridges were almost identical except for a small sensing notch in the upper left corner of the cartridge. This signalled a quadraphonic 8-Track player to combine the odd tracks as audio channels for the first program, and the even tracks as channels for the second program. The format was not fully compatible with stereo or mono 8-Track players – although quadraphonic players would play stereo 8-tracks, playing quadraphonic tapes on stereo players results in hearing only half the channels at a time.

Q8 cartridges had two ‘sides’ whereas 8-Tracks has four sides or programmes. To compensate for the reduction in programmes due to the doubling of tracks, Q8s used thinner tape to try and increase playing time.

Around 200 different Q8 titles were available in mid 1972. Blank media was also available for home recording.

The last release in the quadraphonic 8-track format was in 1978, although most had stopped appearing by the end of 1976.

Quadraphonic open reel tape (Q4) (1969 – mid 1970s)

Quadraphonic open reel tape (Q4) was first introduced by Vanguard Records in 1969, and was only ever available in the US market.

It used ¼-inch tape, playing at a speed of 7½ inches per second, and had 4 fully discrete tracks with full-bandwidth (unlike Q8 cartridges which had limited dynamic range).

Like other quadraphonic formats, it was unsuccessful and had disappeared by the late 1970s.

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