8-track cartridge

:This is an article about the 8-track cartridge. For four track multitracking, see Multitrack_recording.

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The 8-track cartridge is a now-obsolete audio storage magnetic tape cartridge technology, popular during the 1960s and 1970s. The 8-track was created by Bill Lear at Lear Inc. (the company of Lear Jet fame), after Bill Lear took a ride with Earl "Madman" Muntz, who had rigged up an earlier 4-track stereo tape system in his car.

Related Topics:
Audio storage - Magnetic tape - 1960s - 1970s - Bill Lear - Lear - Lear Jet - Earl "Madman" Muntz

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The original format for magnetic tape sound reproduction was reel-to-reel audio tape recording, first made available in the 1940s. However, the machines were bulky and the reels themselves were more difficult to handle than vinyl records. Born from the desire to have an easier to use tape format, the enclosed reel mechanism was introduced in the mid 1950s.

Related Topics:
Magnetic tape - Reel-to-reel audio tape recording - 1940s - 1950s

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The basic cartridge was designed in 1956 around a single reel bearing a continuous loop of standard 1/4 inch plastic oxide-coated recording tape. Program starts and stops were signalled either by a conductive foil splice or sub-audible tones. The 8-track version simplified the mechanism by rolling the motorized metal capstan in the player against a pinch wheel installed inside the cartridge to pull the tape across the player's read head (in the 4-track version, the pinch wheel was part of the player and flipped into the cartridge through a hole). The tape was pulled from the center of the reel, passed across the opening at the end of the cartridge and wound back onto the outside of the same reel. The spool itself was freewheeling and the tape was driven only by tension from the capstan.

Related Topics:
1956 - Capstan - Head

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The tape was coated with a slippery backing material, usually graphite, to ease the continuous slip between the tape layers. This coating sometimes also caused the pinch wheel to slip, leading to poor speed control and tape flutter. Due to these problems, 8-track cartridges were never popular with audiophiles. While the design allowed simple and cheap players, unlike a two-reel system it didn't permit winding of the tape in either direction. Some players offered a limited fast-forward by speeding up the motor while cutting off the audio but rewinding was impossible.

Related Topics:
Graphite - Flutter - Audiophile

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The original 4-track consumer cartridge format had four monaural or two pairs of stereo tracks. A foil splice passed across a pair of contacts close to the read head, signalling the player to switch to the next program track, achieved by physically moving the head up and down mechanically in most cases.

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A professional version used in broadcasting, called a cart, acheived much wider bandwidth with single full-track mono or a half-track stereo pair, along with sub-audible tones for fast cues and a fixed, non-moving playback head. While this provided higher fidelity and was extremely convenient and reliable for busy disc jockeys and studio engineers, program length was usually limited to that of a single song and the cartridges required some maintenance, making the format too expensive and limited for consumer use.

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In all versions the cartridge played continuously with no rewinding, though there was usually a short gap in the audio at the splice in the tape loop. 8-track cartidges doubled playing time by recording four stereo tracks (for a total of eight) on the tape, although this made each track half as wide, reducing the sound quality. The term 4-track cartridge was created by back-formation.

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Besides mediocre audio quality, 8-tracks were plagued by a pause and mechanical click (often in the middle of a recording) as tracks were switched, and faint audio bleed of adjacent tracks into the currently playing track. Also, the delicate cartridge mechanism was prone to breakage, so 8-tracks had generally short lives.

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The popularity of both 4-track and 8-track cartridges grew from the booming automobile industry. In 1965, Ford Motor Company introduced built-in 8-track players as a custom option. By 1966, all of their vehicles offered this upgrade. Thanks to Ford's backing, the 8-track format eventually won out over the 4-track format.

Related Topics:
Automobile - 1965 - Ford Motor Company - 1966

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Despite mediocre audio quality and the problems of fitting a standard vinyl LP album onto a four-program cartridge, the format gained steady popularity due to its convenience and portability. Home players were introduced in 1967. With the availability of cartridge systems for the home, consumers started thinking of 8-tracks as a viable alternative to vinyl records, not only as a convenience for the car. Within the year, prerecorded releases on 8-track began to come along at nearly the same time as vinyl releases.

Related Topics:
1967 - Vinyl record

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The devices were especially popular among professional truck drivers as this was the first successful prerecorded playback device for use in a moving vehicle. Earlier attempts to apply mechanical disk players were troubled by skipping induced by vehicle motion.

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Quadraphonic 8-track cartridges (known as Q8's) were also produced. The format enjoyed a moderate amount of success for a time but faded in the mid-1970s. These cartridges are prized by collectors since they provide 4 channels of discrete sound, unlike matrixed formats such as SQ.

Related Topics:
Quadraphonic - Discrete - Matrixed

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However, another format appeared by 1972. The stereo compact audio cassette was much less than half the size of an 8-track cartridge. The cassette had been around as a monophonic dictation device since 1965, but was now a stereo, higher fidelity alternative.

Related Topics:
1972 - Compact audio cassette - 1965

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8-track players remained a common feature in some homes and automobiles until the early 1980s, slowly fading into obscurity. By the time the compact disc arrived in the mid 1980s the 8-track had all but vanished except among collectors. However the professional cart format, based on the earliest design, survived for another decade at most radio stations where it was an industry standard for playing jingles, advertisements, station identifications and music content for over forty years before being replaced with various computer based methods by the late 1990s.

Related Topics:
1980s - Compact disc - Jingle - Advertisement

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The center extraction tape concept continues to be used in modern cinema movie projectors, although in that application the spool is actively rotated and not drawn by tension on the film.

Related Topics:
Cinema - Movie projectors

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See Also:

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• PlayTape
• Compact audio cassette
• List of audio formats
• Madman Muntz
 
8-track cartridge: External links ►