The 8-track tape (formally Stereo 8; commonly called eight-track cartridge, eight-track tape, and eight-track) is a magnetic-tape sound recording technology that was popular from the mid-1960s to the early 1980s, when the compact cassette, which pre-dated the 8-track system, surpassed it in popularity for pre-recorded music. 

The format was commonly used in cars and was most popular in the United States and Canada and, to a lesser extent, in the United Kingdom. One advantage of the 8-track tape cartridge was that it could play continuously in an endless loop, and did not have to be "flipped over" to play the entire tape. After about 80 minutes of playing time, the tape would start again at the beginning. Because of the loop, there is no rewind. The only options the consumer has are play, fast forward, record, and program (track) change.

The Stereo 8 Cartridge was created in 1964 by a consortium led by Bill Lear, of Lear Jet Corporation, along with Ampex, Ford Motor Company, General Motors, Motorola, and RCA Victor Records (RCA - Radio Corporation of America). 

The 8-track tape format is now considered obsolete, although there are collectors that refurbish these tapes and players as well as some bands that issue these tapes as a novelty. Cheap Trick's The Latest in 2009 was issued on 8-track, as was Dolly Parton's A Holly Dolly Christmas in 2020, the latter with an exclusive bonus track. Little Lost Girl Media from Oregon is currently still making 8-tracks and runs a mostly 8-track rock-n-roll record label.

Technology 
The cartridge's dimensions are approximately . The magnetic tape is played at 3–3/4 inches per second (twice the speed of a cassette), is wound around a single spool, is about  wide and contains 8 parallel tracks. The player's head reads two of these tracks at a time, for stereo sound. After completing a program, the head mechanically switches to another set of two tracks, creating a characteristic clicking noise.

History

Development

Inventor George Eash invented a design in 1953, called the Fidelipac cartridge, also called the NAB cartridge. which would later be used in not only the Muntz Stereo-Pak but also in various monaural background music systems from the `late 60s to the early `90s.

His inspiration came from one of the first products that used the Endless tape cartridge technology which was the Audio Vendor from a year earlier, an invention of Bernard Cousino. The tape is passed through an inner ring of loose tape reel, where the recording is stored, and looped back through the outer ring of the reel. Initially, this mechanism was to be implemented in a reel-to-reel audio tape recorder.

Later, Cousino developed a plastic case that could be hung up on some existing tape recorders. This cartridge was marketed by John Herbert Orr as Orrtronic Tapette. In this generation, the magnetic coating of the tape was wound on the `inside' of the reel. Later cartridge types had the magnetic layer aligned to the `outside' of the cartridge, which required a specially designed recorder to play it. Once traction of the tape by capstan was added, it allowed users the convenience of just pushing the cartridge into the recorder without having to thread the tape. These cassettes needed no internal space for the tape head slider because they accessed the tape from outside the cartridge.

Based on these new cassettes, George Eash developed the Fidelipac cartridge in 1954. PlayTape and the endless-loop compact cassettes for the announcement text of answering machines were made with this technique as well along with other similar but incompatible answering machine tapes. The original separate take-up reel got a platter laid under the supply reel to combine the two and the perforation around the edge of the reel for traction was removed. There was no rear winding reel inside such a cassette so rewinding was impossible. Previously, a similar technique was used to store Tefifon grooved-vinyl sonic tape in the Tefi cartridge but without the benefit of a reel due to the width being 16MM, over twice that of an 8-track and due to the thickness of the film at 3 mils. 

Another similar technology was the LaBelle Tutor 16 which combined several endless loop technologies at once. A 35MM filmstrip was reduced to 16 MM and loaded into an endless loop film cartridge similar to a Fisher Price Movie Viewer which used silent truncated versions of 16 MM cartoons. The bottom of this cartridge acted as the top for the sound cartridge below it which was basically identical to an 8-track. The only difference was the recording was the same 2-track format as mono NAB carts at the same 3-3/4 IPS speed as an 8-track with the program material on one track and the subsonic picture-change automation tone on the other track.

Films, both silent as well as sound, in 8MM as well as 16 MM configurations and in optical as well as magnetic sound formats were also endless loops, used in everything from store end-cap sales tools, to on-the-road engineering instructions to early portable airline movies. Instead of having any part of the mechanism located inside the cartridge, the only part located there was a 45-degree mirror to reflect the light through the film and onto either the internal frosted screen or an external screen by way of flipping another mirror in to redirect the picture.

Stereo 8 

The Lear Jet Stereo 8 cartridge was designed by Richard Kraus while working for the Lear Jet Corporation, under Bill Lear, in 1963. The major change was to incorporate a neoprene rubber and nylon pinch roller into the cartridge itself, rather than to make the pinch roller a part of the tape player, reducing mechanical complexity. Lear also eliminated some of the internal parts of the Eash cartridge, such as the tape-tensioning mechanism and an interlock that prevented tape slippage. Because the Stereo-Pak cartridges were prone to jamming due to their complex design, Lear endeavored to redesign them, putting twice the number of tracks on them, doubling their recording time first to 80 minutes and then extending that to 100 minutes.

Discrete Quadraphonic 8-track 
Four-channel 8-tracks were distinguishable by the notch in the upper left hand corner as in the picture to the right. Blanks such as this one were sold with a white spacer occupying the notch the same as 45 rpm adapter were sold to convert 7-inch large hole singles so that they could be played on conventional turntables. This notch activated the second set of tracks on the new head which would have originally played Programs 3 and 4 of a stereo tape and used them simultaneously with heads that would read Programs 1 and 2.

Tapes were first marketed for the Fall, 1970 music season which is a little strange, due to the fact that the last Stereo-Pak four TRACK Muntz cartridge tapes (vs four CHANNEL quadraphonic) were still being produced at the same time as well as regular Stereo 8 tapes.

Time Limitations 
Going back to using the same amount of tape for an album as a Stereo-Pak was a little annoying to consumers since the whole idea of Two Albums on One Tape for The Same Low Price (as an LP) were now an impossibility, forcing the quadraphonic issues of double albums on 8-track being forced to occupy two or even (in the case of classical music) three tapes. 

If an album ran over 50 minutes in length, since the maximum number of time that could be crammed into a STEREO 8-track was 100 minutes, if there wasn't enough program material to make a second tape, some songs would be edited or eliminated entirely to fit within the 25-minute-per-program time limit - meaning they were going back to a slightly lesser version of the same truncated program problems that 2-track stereo tape had to deal with 20 years earlier. Quadraphonic cassettes were experimented with starting in 1974, but never gained a toe-hold until cassette portastudios established themselves ten years later just before digital took off.

Commercial success 

The popularity of both four-track and eight-track cartridges grew from the booming automobile industry. In September 1965, the Ford Motor Company introduced factory-installed and dealer-installed eight-track tape players as an option on three of its 1966 models (the sporty Mustang, luxurious Thunderbird, and high-end Lincoln), and RCA Victor introduced 175 Stereo-8 Cartridges from its RCA Victor and RCA Camden labels of recording artists catalogs. By the 1967 model year, all of Ford's vehicles offered this tape player upgrade option. Most of the initial factory installations were separate players from the radio (such as shown in the image), but dashboard mounted 8-track units were offered in combination with an AM radio, as well as with AM/FM receivers. 

The 8-track format gained steadily in popularity because of its convenience and portability. Home players were introduced in 1966 that allowed consumers to share tapes between their homes and portable systems. By the late 1960s, the 8-track segment was the largest in the USA consumer electronics market (Low UK & Europe sales as Compact Cassette was released 1962) and the popularity of 8-track systems for cars helped generate demand for home units. "Boombox" type portable players were also popular but eight-track player/recorders failed to gain wide popularity and few manufacturers offered them except for manufacturer Tandy Corporation (for its Radio Shack electronics stores). With the availability of cartridge systems for the home, consumers started thinking of eight-tracks as a viable alternative to 33 rpm album style vinyl records, not only as a convenience for the car. Also by the late 1960s, prerecorded releases on the 8-track tape format began to arrive within a month of the vinyl release. The 8-track format became by far the most popular and offered the largest music library of all the tape systems in the USA.

Early karaoke machines 
Daisuke Inoue invented the first karaoke machine in 1971 called the Juke-8.

Other use 
Milton Bradley's (MB) OMNI Entertainment System was an electronic quiz machine game first released in 1980, similar to Jeopardy! or later entries in the You Don't Know Jack video game series, using 8-track tapes for questions, instructions, and answers, using audio playback as well as digital signals in magnetic-tape data storage on remaining tracks to load the right answer for counting the score. In 1978, the Mego Corporation launched the 2-XL toy robot, which utilized the tracks for determining right from wrong answers. In 1977, the Scottish company GR International released the Bandmaster Powerhouse, a drum machine that played back custom-made 8-track cartridges similar to a Mellotron or Chamberlin Music Master containing drum and percussion rhythm loops recorded with real instruments. These could be subjected to a degree of processing using the drum machine's controls, which included tempo and instrument balance.

Decline
1978 was the peak year for 8-track sales in the United States, with sales declining rapidly from then on. Eight-track players became less common in homes and vehicles in the late 1970s. The compact cassette had arrived in 1963. 

In the U.S., eight-track cartridges were phased out of retail stores in late 1982 and early 1983. However, some titles were still available as eight-track tapes through Columbia House and RCA (BMG) Music Service Record Clubs until late 1988. Until 1990, Radio Shack (Tandy Corporation) continued to sell blank eight-track cartridges and players for home recording use under its Realistic brand.

See also 
 Album era
 Timeline of audio formats
 Sound recording and reproduction
 Birotron

References

External links 

 "A Survey of Recordable Magnetic Media" by Andrew D. Crews, December, 2003, University of Texas, accessed 8 August 2006
 So Wrong They're Right - A 1995 documentary about 8-track enthusiasts
 8-Track Heaven
 8-Track Moments Listen to the sound of the 8-Track click
 Bill Lear Invents the 8-Track and Brings in Ford, Motorola, and RCA Victor. Recording History.org

Audiovisual introductions in 1964
Audio storage
History of sound recording
Tape recording
Discontinued media formats
Quadraphonic sound
American inventions
1964 in music
1964 in technology
Products introduced in 1964
1970s fads and trends