Compact Cassette
Typical 60-minute Compact Cassette
Media type	magnetic tape
Encoding	analog signal
Capacity	variable Common tape lengths: 7 minutes per side (C14) 15 minutes per side (C30) 23 minutes per side (C46) 30 minutes per side (C60) 37 minutes per side(C74) 45 minutes per side (C90) 50 minutes per side (C100) 60 minutes per side (C120)
Read mechanism	tape head
Write mechanism	magnetic recording head
Usage	audio and data storage

The Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a magnetic tape sound recording format. Magnetic tape is a medium for Magnetic recording generally consisting of a thin magnetizable coating on a long and narrow strip of Plastic. Mifu01jpg|200px|thumb|right|Chinese calligraphy written in a language content format by Song Dynasty (A An analog or analogue signal is any continuous signal for which the time varying feature (variable of the signal is a representation of some other A tape head is a type of Transducer used in Tape recorders to convert electrical signals to magnetic fluctuations and vice versa In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. A recording head is the physical interface between a Recording apparatus and a moving Recording medium. Magnetic tape is a medium for Magnetic recording generally consisting of a thin magnetizable coating on a long and narrow strip of Plastic. Although it was originally intended as a medium for dictation, improvements in fidelity led the Compact Cassette to supplant reel-to-reel tape recording in most non-professional applications. Fidelity is a notion that at its most abstract level implies a truthful connection to a source or sources Reel-to-reel, open reel tape recording is the form of magnetic tape audio recording in which the recording medium is held on a Reel, rather than being ^[1] Its uses ranged from portable audio to home recording to data storage for early microcomputers. microcomputer is a Computer with a Microprocessor as its Central processing unit. Between the early 1970s and late 1990s, the cassette was one of the two most common formats for prerecorded music, first alongside the LP and later the Compact Disc. A gramophone A Compact Disc (also known as a CD) is an Optical disc used to store digital data, originally developed for storing digital audio ^[2] The word cassette is a French word meaning "little box. "

Compact Cassettes consist of two miniature spools, between which a magnetically coated plastic tape is passed and wound. These spools and their attendant parts are held inside a protective plastic shell. Two stereo pairs of tracks (four total) or two monaural audio tracks are available on the tape; one stereo pair or one monophonic track is played or recorded when the tape is moving in one direction and the second pair when moving in the other direction. Stereophonic sound, commonly called stereo, is the reproduction of Sound, using two or more independent audio channels through a Symmetrical Monaural (often shortened to mono) sound reproduction is single-channel This reversal is achieved either by manually flipping the cassette or by having the machine itself change the direction of tape movement ("auto-reverse"). ^[3]

History

Philips introduced the compact audio cassette medium for audio storage in Europe in 1963, and in the United States in 1964, under the trademark name Compact Cassette. Koninklijke Philips Electronics NV ( Royal Philips Electronics Inc. The United States of America —commonly referred to as the A trademark or trade mark, represented by the symbols ™ and ®, or mark is a distinctive sign or indicator used by an individual Although there were other magnetic tape cartridge systems at the time, the Compact Cassette became dominant as a result of Philips's decision (in the face of pressure from Sony) to license the format free of charge. is a multinational conglomerate corporation headquartered in Minato Tokyo, Japan, and one of the world's largest Media conglomerates with The verb license or grant license means to give permission The noun license is the document demonstrating that permission It went on to become a popular (and re-recordable) alternative to the turntable for LP records during the late 1970s. The phonograph, or gramophone, was the most common device for playing recorded Sound from the 1870s through the 1980s Long play (LP record albums are 33⅓  Rpm vinyl Gramophone records (phonograph records generally either 10- or 12- Inches in diameter ^[2]

Introduction of music cassettes

The mass production of compact audio cassettes began in 1964 in Hanover, Germany. Hanover (i ( haˈnoːfɐ on the river Leine, is the capital of the federal state of Lower Saxony ( Niedersachsen Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Prerecorded music cassettes (also known as Musicassettes; M. Music is an Art form in which the medium is Sound organized in Time. C. for short) were launched in Europe in late 1965. The Mercury Record Company, a U. S. affiliate of Philips, introduced M. C. to the U. S. in September 1966. The initial offering consisted of 49 titles. ^[4]

However, the system had been initially designed for dictation and portable use, with the audio quality of early players not well suited for music. Some early models also had unreliable mechanical design. In 1971 the Advent Corporation introduced their Model 201 tape deck that combined Dolby type B noise reduction and chromium dioxide (CrO₂) tape, with a commercial-grade tape transport mechanism supplied by the Wollensak camera division of 3M Corporation. Henry Kloss (1929 Altoona PA &ndash January 31, 2002, Cambridge MA) was a prominent audio engineer and businessman who helped advance Dolby NR is the name given to a series of noise reduction systems developed by Dolby Laboratories for use in analogue Magnetic tape recording Chromium dioxide or chromium(IV oxide is a synthetic magnetic substance once widely used in Magnetic tape Emulsion. This resulted in the format being taken more seriously for musical use, and started the era of high-fidelity cassettes and players. High fidelity or hi-fi reproduction is a term used by home stereo listeners and home audio enthusiasts ( Audiophiles to refer to high-quality reproduction ^[1]

During the 1980s, the cassette's popularity grew further as a result of portable pocket recorders and hi-fi players such as Sony's Walkman, which used a body not much larger than the cassette tape itself, with mechanical keys on one side, or electronic buttons or display on the face. Walkman is a popular Sony Brand used to market its portable audio and Video players Some would partially collapse if they were not actually holding a cassette.

1979 Sony Walkman

As the transistor radio defined small music in the 1960s, the portable CD player in the 1990s, and the MP3 player in the 2000s, so did the Walkman define very small portable music in the 1980s, with cassette sales overtaking those of LPs. Walkman is a popular Sony Brand used to market its portable audio and Video players This article is about an electronic device For the fourth studio album by M A digital audio player, more commonly referred to as an MP3 player, is a Consumer electronics device that stores organizes and plays audio files Some A gramophone ^[5][2] Total vinyl record sales remained higher well into the 1980s due to greater sales of singles, although cassette singles achieved popularity for a period in the 1990s. A gramophone A cassette single ( CS, also known by the trademark " Cassingle " or capitalized as the trademark " Cassette Single " is a music single ^[5]

Apart from the purely technical advances cassettes brought, they also served as catalysts for social change. Their durability and ease of copying helped bring underground rock and punk music behind the Iron Curtain, creating a foothold for Western culture among the younger generations. The " Iron Curtain " was the symbolic ideological and physical boundary dividing Europe into two separate areas from the end of World War II until the end ^[6] For similar reasons, cassettes became popular in developing nations.

One of the most famous political uses of cassette tapes was the dissemination of sermons by the Ayatollah Khomeini throughout Iran before the 1979 Iranian revolution, in which Khomeini urged the overthrow of the regime of the Shah. Seyyed Ruhollah Musavi Khomeini ( Persian:, pronounced muːsæviː-je xomejniː}}( September 24, 1902 – June 3 1989 For a topic outline on this subject see List of basic Iran topics. The Iranian Revolution' (mostly known as the Islamic Revolution, Persian: انقلاب اسلامی Enghelābe Eslāmi was the Revolution that transformed

In 1970s India, they were blamed for bringing unwanted secular influences into traditionally religious areas. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country Cassette technology created a booming market for pop music in India, drawing criticism from conservatives while at the same time creating a huge market for legitimate recording companies and pirated tapes. ^[7] In some countries, particularly in the developing countries, cassettes still remain the dominant medium for purchasing and listening to music. Developing countries are countries that haven't reached Western-style standards of democratic government free market economy industrialization social programs and human rights guaranties ^[8]

Decline

In many Western countries, the market for cassettes has declined sharply since its peak in the late 1980s. This has been particularly noticeable with pre-recorded cassettes, whose sales were overtaken by those of Compact Discs during the early 1990s. A Compact Disc (also known as a CD) is an Optical disc used to store digital data, originally developed for storing digital audio By 1993, annual shipments of CD players had reached 5 million, up 21% from the year before, while cassette player shipments had dropped 7% to approximately 3. 4 million. ^[9] The decline continued such that in 2001 cassettes accounted for only 4% of all music sold. Since then, the pre-recorded market has undergone further decline, with few retailers stocking them because they are no longer issued by the major music labels. ^[8] Sales of music cassettes in the U. S. dropped from 442 million in 1990 to about 700,000 in 2006. ^[10] However, as of early 2008, blank cassettes are still being produced and are sold at many retail stores, and facilities for cassette duplication remain available. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Cassette recorders and players are gradually becoming scarcer, but are still widely available and still feature in a notable percentage of Hi-Fi systems. ^[11]

Cassettes remained popular for specific applications, such as car audio, well into the 1990s. Car audio/video (car AV is a term used to describe the sound or video system fitted in an Automobile. Cassettes and their players were typically more rugged and resistant to dust, heat and shocks than the main digital competitor (the CD). Their lower fidelity was not considered a serious drawback inside the typically noisy automobile interior of the time. However, the advent of "shock proof" buffering technology in CD players, the reduction in in-car noise levels and the general heightening of consumer expectations meant that by the late 1990s, the CD had replaced the cassette as the default audio component in the majority of new vehicles in Europe and America. Electronic skip protection is a memory buffer system used mainly in some portable Compact Disc (CD players and all MiniDisc (MD units

While digital voice recorders are now common, Compact Cassette (or frequently microcassette) recorders tend to be cheaper and of sufficient quality to serve as adjuncts or substitutes for note taking in business and educational settings. A Microcassette (often written generically as microcassette) is an Audio storage medium introduced by Olympus in 1969. Audiobooks, church services, and other spoken word material are still frequently sold on cassette, as lower fidelity is generally not a drawback for such content. While most publishers sell CD audiobooks, they usually also offer a cassette version at the same price. In the audiobooks application, where recordings may span several hours, cassettes also have the advantage of holding up to 120 minutes of material whereas the average CD holds less than 80. ^[11]

While cassettes and related equipment have become increasingly marginal in commercial music sales, recording on analog tape remains a desirable option for some.

Features of the cassette

The cassette was a great step forward in convenience from reel-to-reel audio tape recording, though because of the limitations of the cassette's size and speed, it initially compared poorly in quality. Reel-to-reel, open reel tape recording is the form of magnetic tape audio recording in which the recording medium is held on a Reel, rather than being Unlike the 4-track stereo open reel format, the two stereo tracks of each side lie adjacent to each other rather than being interleaved with the tracks of the other side. This permitted monaural cassette players to play stereo recordings "summed" as mono tracks and permitted stereo players to play mono recordings through both speakers. The tape is 3. 81 mm (0. 150 in) wide, with each stereo track 0. 6 mm wide and an unrecorded guard band between each track. The tape moves at 4. 76 cm/s (1 7/8 in/s) from left to right. The inch per second is a unit of Speed or Velocity. It expresses the Distance in Inches ( in) traveled or displaced divided ^[12] For comparison, the typical open reel format in consumer use was ¼ inch (6. 35 mm) wide, each stereo track nominally ¹⁄₁₆ inch (1. 59 mm) wide, and running at either 9. 5 or 19 cm/s (3. 75 or 7. 5 in/s).

Cassette types

Notches on the top surface of the audio cassette indicate its type. The top cassette, with only write protect notches (here covered by write protect tabs), is a Type I. The next cassette down, with additional notches adjacent to the write protect notch, is a Type II. The bottom two cassettes, featuring the Type II notches plus an additional pair in the middle of the cassette are type IV (metal); note the removal of the tabs on the second of these, meaning the tape is write-protected.

Cassette tapes are made of a polyester type plastic film with a magnetic coating. Polyester is a category of Polymers which contain the Ester Functional group in their main chain The original magnetic material was based on gamma ferric oxide (Fe₂O₃). Iron(III oxide —also known as ferric oxide, Hematite, red iron oxide, synthetic maghemite, colcothar, or simply Rust —is Circa 1970, 3M Company developed a cobalt volume-doping process combined with a double-coating technique to enhance overall tape output levels. 3M Company ( formerly Minnesota Mining and Manufacturing Company until 2002 is an American multinational conglomerate corporation with a worldwide This product was marketed as "High Energy" under its Scotch brand of recording tapes. ^[13] Inexpensive cassettes are commonly labeled "low-noise", but typically are not optimized for high frequency response. Frequency response is the measure of any system's spectrum response at the output to a signal of varying Frequency (but constant amplitude at its input

At about the same time chromium dioxide (CrO₂) was introduced by BASF,^[14] and then coatings using magnetite (Fe₃O₄) such as TDK's Audua were produced in an attempt to approach the sound quality of vinyl records. Chromium dioxide or chromium(IV oxide is a synthetic magnetic substance once widely used in Magnetic tape Emulsion. BASF SE () is a German chemical company and the largest chemical company in the world Magnetite is not to be confused with Magnesite or Maghemite. Magnetite is a ferrimagnetic Mineral with chemical formerly, is a Japanese company that manufactures electronic materials Electronic components and recording and data-storage media, and markets them globally A gramophone Cobalt-adsorbed iron oxide (Avilyn) was introduced by TDK in 1974 and proved very successful. Cobalt (ˈkoʊbɒlt is a hard lustrous silver-grey Metal, a Chemical element with symbol Co. Finally pure metal particles (as opposed to oxide formulations) were introduced in 1979 by 3M under the trade name Metafine. The tape coating on most Cassettes sold today as either "Normal" or "Chrome" consists of Ferric Oxide and Cobalt mixed in varying ratios (and using various processes); there are very few cassettes on the market that use a pure (CrO₂) coating. ^[2]

Simple voice recorders are designed to work with standard ferric formulations. High fidelity tape decks are usually built with switches or detectors for the different bias and equalization requirements for high performance tapes. Tape bias is the term for two phenomena DC bias and AC bias, that improve the fidelity of analogue Magnetic tape sound recordings DC bias is the addition Equalization (or equalisation, EQ) is the process of changing the frequency envelope of a sound in Audio processing. The most common, iron oxide tapes (defined by an IEC standard as "Type I"), use 120 µs playback equalization, while chrome and cobalt-absorbed tapes (IEC Type II) require 70 µs playback equalization. The International Electrotechnical Commission ( IEC) is a not-for-profit, non-governmental international Standards organization that prepares and publishes The second ( SI symbol s) sometimes abbreviated sec, is the name of a unit of Time, and is the International System of Units The recording "bias" equalizations were also different (and had a much longer time constant). Sony tried a dual layer tape with both ferric oxide and chrome dioxide known as 'ferrichrome' (FeCr) (IEC Type III) but these were only available for a short time in the 1970s. is a multinational conglomerate corporation headquartered in Minato Tokyo, Japan, and one of the world's largest Media conglomerates with Metal Cassettes (IEC Type IV), also use 70 µs playback equalization, and provide still further improvements in sound quality, as well as improved resistance to wear. ^[13] The quality is normally reflected in the price; Type I cassettes are generally cheapest, and Type IV usually the most expensive. BASF developed a chrome cassette designed for use with 120 µs (type I) playback equalization (for improved compatibility with equipment lacking a 70 µs setting) but this idea only caught on for commercially pre-recorded cassettes. ^[2]

Notches on top of the cassette shell indicate the type of tape within. Type I cassettes only have write-protect notches, Type II have an additional pair next to the write protection ones, and Type IV (metal) have a third set in the middle of the cassette shell. Write protection is any physical mechanism that prevents modification or erasure of valuable Data on a device These allow cassette decks to automatically detect the tape type and select the proper bias and equalization. A cassette deck is a type of Tape recorder for playing or recording audio Compact cassettes A deck was formerly distinguished from a recorder Many inexpensive models (and the majority of those manufactured recently) may lack this feature. Playback of Type II and IV tapes on such a player will produce exaggerated treble, but it may not be noticeable because typically such devices have amplifiers that lack extended high frequency output. Recording on these units however results in very low sound reproduction and sometimes distortion and hiss is heard. Also, these cheaper units cannot erase high bias or metal bias tapes. Attempting to do so will result in "print-through". Print-through (sometimes referred to as bleed-through) is a generally undesirable effect that arises in the use of Magnetic tape for storing analogue information

Playback length

Cassettes of varying tape quality and playing time

Tape length is usually measured in minutes of total playing time. The most popular varieties are C46 (23 minutes per side), C60 (30 minutes per side), C90, and C120. The C46 and C60 lengths are typically 15–16 µm thick, but C90s are 10–11 µm and C120s are just 9 µm thick, rendering them more susceptible to stretching or breakage. A micrometre ( American spelling: micrometer; symbol µm) is one millionth of a Metre, or equivalently one thousandth of a Millimetre Some vendors are more generous than others, providing 132 meters or 135 meters rather than 129 meters of tape for a C90 cassette. C180 and even C240 tapes were available at one time, but these were extremely thin and fragile and suffered badly from effects such as print-through, which made them unsuitable for general use. Print-through (sometimes referred to as bleed-through) is a generally undesirable effect that arises in the use of Magnetic tape for storing analogue information Other lengths are (or were) also available from some vendors, including C10 and C15 (useful for saving data from early home computers), C30, C50, C54, C64, C70, C74, C80, C84, C100, C105, and C110. ^[13]

Some companies included a complimentary blank cassette with their portable cassette recorders in the early 1980s. Panasonic's was a C14 and came with a song recorded on side one, and a blank side two. Except for C74 and C100, such non-standard lengths have always been hard to find, and tend to be more expensive than the more popular lengths. Home taping enthusiasts may have found certain lengths useful for fitting an album neatly on one or both sides of a tape. For instance, the initial maximum playback time of Compact Discs was 74 minutes, explaining the relative popularity of C74 cassettes.

Inside a cassette. "Supply reel" and "takeup reel" are from the point of view of the player looking at the back of the cassette: when viewed from the front of the machine, the tape "plays" from left to right (though of course an auto-reverse deck can play in either direction). The tape is pressed into close contact with the head by the pressure pad; guide rollers help keep the tape in the correct position. Smooth running is assisted by a slippery liner between the spools and the shell; here the liner is transparent. The magnetic shield reduces pickup of stray signals by the heads of the player.

Write-protection

All cassettes include a write protection mechanism to prevent re-recording and accidental erasure of important material. Write protection is any physical mechanism that prevents modification or erasure of valuable Data on a device Each side of the cassette has a plastic tab on the top that may be broken off, leaving a small indentation in the shell. This indentation allows the entry of a sensing lever that prevents the operation of the recording function when the cassette is inserted into a cassette deck. If the cassette is held with one of the labels facing the user and the tape opening at the bottom, the write-protect tab for the corresponding side is at the top-left. Occasionally, manufacturers provided a movable panel that could be used to enable or disable write-protect on tapes.

If later required, a piece of adhesive tape can be placed over the indentation to bypass the protection, or (on some decks), the lever can be manually depressed to record on a protected tape. Adhesive tape can be one of many varieties of backing materials coated with an Adhesive. Extra care is required to avoid covering the additional indents on high bias tape cassettes adjacent to the write-protect tabs. Tape bias is the term for two phenomena DC bias and AC bias, that improve the fidelity of analogue Magnetic tape sound recordings DC bias is the addition

Cassette players and recorders

The first cassette machines were simple mono record and playback units. Early machines required attaching an external dynamic microphone. Most units after the 1970s also incorporated built-in condenser microphones, which have extended high frequency response, but may also pick up noises from the recorder motor. A common portable recorder format still common today is a long box, the width of a cassette, with a speaker at the top, a cassette bay in the middle, and "piano key" controls at the bottom edge. The markings of "piano key" controls near the handle were soon standardized and is a legacy still emulated on many software control panels, though many DVD panels have eliminated the fast forward and rewind buttons in favor of next and previous tracks, which are only implemented on machines which have logic to search for blank spots in the tape. These symbols are commonly the square for stop, right pointing triangle for play, double triangles for fast forward and rewind, red dot for record, and a vertically-divided square (two rectangles side-by-side) for the pause button. Another format is only slightly larger than the cassette, also adapted for stereo "Walkman" player applications.

Main article: Cassette deck

A typical portable desktop cassette recorder from RadioShack. A cassette deck is a type of Tape recorder for playing or recording audio Compact cassettes A deck was formerly distinguished from a recorder RadioShack Corporation (formerly Tandy Corporation) (  is a chain of electronics retail stores in the United States, as well as parts of North America

Stereo recorders eventually evolved into high fidelity and were known as "cassette decks", after the reel-to-reel "decks". Many formats of cassette players and recorders have evolved over the years. Initially all were top loading, usually with cassette on one side, VU meters and recording level controls on the other side. A VU meter is often included in analog audio equipment to display a Signal level in Volume Units. Older models used combinations of levers and sliding buttons for control.

Nakamichi RX-505 audio cassette deck

A major innovation was the front-loading arrangement. is a historic Japanese High end audio company most famous for its innovative and very high quality cassette decks is a historic Japanese High end audio company most famous for its innovative and very high quality cassette decks Pioneer's angled cassette bay and the exposed bays of some Sansui models were eventually standardized as a front-loading door into which a cassette would be loaded. ( is a Multinational Corporation that specializes in digital entertainment products based in Tokyo, Japan. Later models would adopt electronic buttons, and replace conventional meters (which could be "pegged" when overloaded) with electronic LED or vacuum fluorescent displays, with level controls typically either being controlled by rotary controls or side-by-side sliders. A vacuum fluorescent display (VFD is a Display device used commonly on consumer-electronics equipment such as Video cassette recorders Car radios BIC and Marantz briefly offered models which could be run at double speeds, but Nakamichi was widely recognized as one of the first companies to create decks which rivaled reel-to-reel decks with frequency response from the full 20–20,000 Hz range, low noise, and very low wow and flutter. is a historic Japanese High end audio company most famous for its innovative and very high quality cassette decks Wow is a relatively slow form of Flutter (pitch variation which can affect both gramophone records and Tape recorders In the latter the collective expression ^[15][16] The 3 headed closed-loop dual capstan Nakamichi 1000 (1973) is considered to be the first truly Audiophile High Fidelity Cassette Deck ever made. Unlike typical cassette decks, the recording and playback functions were split onto separate heads (with the third head being the erase head), allowing each to be optimized.

Other contenders for the highest, "HiFi" quality on this medium were two companies already widely known for their excellent quality reel-to-reel tape recorders: Tandberg and Revox (consumer brand of the Swiss professional Studer company for studio equipment). Tandberg ( is a manufacturer of Video Encoders Multiplexers and Videoconferencing systems located in Oslo, Norway ReVox is a brand name of Swiss audio equipment created by Studer in the 1950s Studer is a Swiss manufacturer of professional audio equipment founded in Zurich in 1948 by Willi Studer Tandberg started with combi-head machines like the TCD 300 and continued with the TCD 3x0 series with separate playback and recording heads. All TCD-models possessed dual capstan drives, beltdriven from a single capstan motor and two separate reel motors. Frequency range extended to 18 kHz. When Tandberg entered the much more competitive TV-market it folded and revived without the HiFi-branch these came from.

Revox went one step further: after hesitating long whether to accept cassettes as a medium capable for meeting their strict standards from reel to reel recorders at all, they produced their B710MK I (Dolby B) and MK II (Dolby B&C) machines. Both cassette units possessed double capstan drives, but with two independent, electronically controlled capstan motors and two separate reel motors. The head assembly moved by actuating a damped solenoid movement, eliminating all kind of belt drives and other wearable parts. These machines rivaled the Nakamichi in frequency and dynamic range. Dynamic range is a term used frequently in numerous fields to describe the Ratio between the smallest and largest possible values of a changeable quantity such as in Sound The B710MKII also achieved 20-20kHZ and dynamics of over 72 dB with Dolby C on chrome and slightly less dynamic range, but a larger headroom with metal tapes and Dolby C. Revox adjusted the frequency range on delivery with many years of use in mind: when new the frequency curve went upwards a few dB at 15-20kHz, aiming for flat response after 15 years of use and headwear to match.

A last step taken by Revox produced even more advanced cassette drives with electronic finetuning of bias and equalization during recording. Revox also produced amplifiers, a very expensive FM tuner and a pickup with a special parallel arm mechanism of their own design. After which this company also got in financial difficulties and Studer had to save itself by folding its Revox-branch and all its consumer products (except their last reel to reel recorder the B77).

Note that while Nakamichi violated the tape recording standards to achieve the highest dynamics possible, producing non-compatible cassettes for playback on other machines, both Tandberg and Revox kept to the standards and produced cassettes which could be played back on other machines.

A third company, the well known Danish Bang & Olufsen invented a special, improved system for improving headroom at high frequencies, to reduce tape saturation despite lower bias levels. Bang & Olufsen ( B&O,) is a Danish company that designs and manufactures high end Audio products Television sets and Telephones This "head room extension method, HX" was called Dolby HX Pro in full and patented. Dolby NR is the name given to a series of noise reduction systems developed by Dolby Laboratories for use in analogue Magnetic tape recording Their finest machine with HX Pro was the Beocord 8000, which indeed performed excellently as far as electronics were concerned. However, this machine possessed only one drive motor and many belt and wheels in a complicated arrangement. The effect, higher wow and flutter levels with less than perfect cassettes, did not make the B&O contender a popular choice with HiFi enthusiasts. Bang & Olufsen ( B&O,) is a Danish company that designs and manufactures high end Audio products Television sets and Telephones Most of them favored Nakamichi, Tandberg or Revox instead, which all were mechanically much more reliable over the years. HX Pro was adopted by other manufacturers than B&O, Technics was one of them.

As they became aimed at more casual users, fewer decks had microphone inputs. Dual decks became popular and incorporated into home entertainment systems of all sizes for tape dubbing. Although the quality would suffer each time a source was copied, there are no mechanical restrictions on copying from a record, radio, or another cassette source. Even as CD recorders are becoming more popular, some incorporate cassette decks for professional applications.

An assortment of boomboxes

Another format that made an impact on culture in the 1980s was the "boom box" which combined the portable cassette deck with speakers capable of producing significant sound levels. BoomBox is an American Rock band, which was founded in 2004 by singer/songwriter Zion Godchaux on the Guitar / Lead vocals and producer/DJ BoomBox is an American Rock band, which was founded in 2004 by singer/songwriter Zion Godchaux on the Guitar / Lead vocals and producer/DJ The boom box became synonymous with urban youth culture in entertainment, which led to the somewhat derisive nickname "ghetto blaster".

Applications for car stereos varied widely. Auto manufacturers in the U. S. would typically fit a cassette slot into their standard large radio faceplates. Europe and Asia would standardize on DIN and double DIN sized faceplates. International standard ISO 7736 defines a standard size for Car audio Head units The standard was originally established by the German standards body Deutsches In the 1980s, a high end installation would have a Dolby AM/FM cassette deck, and they rendered the 8-track cartridge obsolete in car installations because of space, performance and audio quality. This is an article about the 8-track cartridge For eight-track multitracking see Multitrack recording. As the cost of building CD players declined, many manufacturers offered a CD player, but some cars, especially those targeted at older drivers still offer the option of a cassette player, either by itself, or sometimes in combination with a CD slot. The newest cars often are not designed to accommodate any cassette drive, but the auxiliary jack advertised for MP3 players can also be used with portable cassette players.

A head cleaning cassette

Although the cassettes themselves were relatively durable, the players required regular maintenance to perform properly. Head cleaning may be done with long swabs, or cassette-shaped devices that could be inserted into a tape deck to polish the heads and remove smudges and dirt. A recording head is the physical interface between a Recording apparatus and a moving Recording medium. Similarly shaped demagnetizers used magnets to degauss the deck, which kept sound from becoming distorted. A common mechanical problem occurred when a worn-out or dirty player rotated the supply spool faster than the take-up spool or failed to release the heads from the tape upon ejection. This would cause the magnetic tape to be fed out through the bottom of the cassette and become tangled in the mechanism of the player. In these cases the player was said to have "eaten" the tape, and it often destroyed the playability of the cassette altogether, and resulted in the common sight of tangled tape on the side of the road. ^[17] Cutting blocks, analogous to those used for open reel 1/4" tape, were readily available though, but mainly used for retrieving valued recordings, through removing the damaged portion of, or repairing the break in, the tape. Creation of compilations was usually by re-recording rather than splicing sections of songs because of the much smaller tape area.

Applications

Audio

The Compact Cassette was originally intended for use in dictation machines. In this capacity, some later-model cassette-based dictation machines could also run the tape at half speed (¹⁵⁄₁₆ in/s) as playback quality was not critical. The Compact Cassette soon became a popular medium for distributing prerecorded music—initially through The Philips Record Company (and subsidiary labels Mercury and Philips in the U. S. ). As of 2006, one finds cassettes used for a variety of purposes such as journalism, oral history, meeting and interview transcripts and so on. Journalism is the profession of writing or communicating formally employed by publications and broadcasters for the benefit of a particular Community of people However, they are starting to give way to Compact Discs and more "compact" storage media.

Home studio

In the 1980s, Tascam introduced the Portastudio line of four and eight-track cassette recorders for home studio use. TASCAM is the professional audio division of TEAC Corporation, headquartered in Tokyo Japan, and is credited as the inventor of the Portastudio, the first TASCAM Portastudio was the world's first four track recorder based on a standard compact audio cassette tape

In the simplest configuration, rather than playing a pair of stereo channels of each side of the cassette, the typical "portastudio" used a four-track tape head assembly to access four tracks on the cassette at once (with the tape playing in one direction). Each track could be recorded to, erased or played back individually, allowing musicians to overdub themselves and create simple multitrack recordings easily, which could then be mixed down to a finished stereo version on an external machine. Overdubbing (the process of making an overdub, or overdubs is a technique used by Recording studios to add a supplementary recorded sound to a previously recorded To increase audio quality in these recorders, the tape speed was sometimes doubled in comparison to the standard; additionally, dbx, Dolby B or Dolby C noise reduction provided compansion (compression of the signal during recording with equal and opposite expansion of the signal during playback), which yields increased dynamic range by lowering the noise level and increasing the maximum signal level before distortion occurs. dbx is a family of noise reduction systems developed by the company of the same name. Dolby NR is the name given to a series of noise reduction systems developed by Dolby Laboratories for use in analogue Magnetic tape recording In Telecommunication, Signal processing, and Thermodynamics, companding (occasionally called compansion) is a method of mitigating the detrimental Dynamic range is a term used frequently in numerous fields to describe the Ratio between the smallest and largest possible values of a changeable quantity such as in Sound Multi-track cassette recorders with built-in mixer and signal routing features ranged from easy-to-use beginner units up to professional-;evel recording systems. ^[18]

Although professional musicians typically only used multitrack cassette machines as "sketchpads", Bruce Springsteen's "Nebraska", was recorded entirely on a four-track. Nebraska is the sixth album by Bruce Springsteen, released in 1982 (see 1982 in music)

Home dubbing

Most cassettes were sold blank and used for recording (dubbing) the owner's records (as backup or to make mixtape compilations), their friends' records or music from the radio. In Sound recording, dubbing is the transfer or copying of previously recorded audio material from one medium to another of the same or a different type A mixtape or mixed tape is a compilation of Songs recorded in a specific order traditionally onto a Compact audio cassette. This practice was condemned by the music industry with such slogans as "Home Taping is Killing Music". " Home Taping Is Killing Music " was the slogan of a 1980s anti- Copyright infringement campaign by the British Phonographic Industry (BPI a British However, many claimed that the medium was ideal for spreading new music and would increase sales, and strongly defended at least their right to copy their own records onto tape. For a limited time in the early 1980s Island Records sold chromium dioxide “One Plus One” cassettes that had an album prerecorded on one side and the other was left blank for the purchaser to use. Island Records is a Record label that was founded by British record producers in Jamaica. Cassettes were also a boon to people wishing to tape concerts (unauthorized or authorized) for sale or trade, a practice tacitly or overtly encouraged by many bands with a more counterculture bent such as the Grateful Dead. A bootleg recording is an audio and/or Video recording of a performance that was not officially released by the artist or under other legal authority The Grateful Dead was an American rock band formed in 1965 in the San Francisco Bay Area. Blank Compact Cassettes also were an invaluable tool to spread the music of unsigned acts, especially within Tape trading networks. The practice of Tape trading is an unofficial method of distribution of demo tapes encompassing musical genres such as punk, hardcore, Thrash

Various legal cases arose surrounding the dubbing of cassettes. In the UK, in the case of CBS Songs v. Amstrad (1988), the House of Lords found in favor of Amstrad that producing equipment that facilitated the dubbing of cassettes, in this case a high-speed twin cassette deck that allowed one cassette to be copied directly onto another, did not constitute the infringement of copyright. Amstrad is an electronics firm based in Brentwood in Essex, England and founded in 1968 by Sir Alan Michael Sugar in the The House of Lords is the second house of the Parliament of the United Kingdom and is also commonly referred to as "the Lords" Amstrad is an electronics firm based in Brentwood in Essex, England and founded in 1968 by Sir Alan Michael Sugar in the ^[19] In a similar case, a shop owner who rented cassettes and sold blank tapes was not liable for copyright infringement even though it was clear that his customers were likely dubbing them at home. ^[20] In both cases, the courts held that manufacturers and retailers could not be held accountable for the actions of consumers.

As an alternative to home dubbing, in the late 1980s, the Personics company installed booths in record stores across America which allowed customers to make personalised mixtapes from a digitally-encoded back-catalogue with customised printed covers.

Data recording

A C2N Datassette recorder for Commodore computers

German-made cassettes sold for computer data recording, circa 1980

The Hewlett Packard HP 9830 was one of the first desktop computers in the early 1970s to use automatically controlled cassette tapes for storage. The Commodore 1530 ( C2N) Datassette (a Portmanteau of Data + cassette) was Commodore 's dedicated computer Tape recorder Commodore, the commonly used name for Commodore International, was a US-American Electronics company based in West Chester Pennsylvania Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. The HP 9800 was a family of what were initially called programmable Calculators and later Desktop computers made by Hewlett-Packard which replaced their first It could save and find files by number, using a clear leader to detect the end of tape. These would be replaced by specialized cartridges such as the 3M DC-series. Many of the earliest microcomputers implemented the Kansas City standard for digital data storage. The Kansas City standard ( KCS) or Byte standard, is a digital data format for audio cassette drives Most home computers of the late 1970s and early 1980s could use cassettes for data storage as a cheaper alternative to floppy disks, though users often had to manually stop and start a cassette recorder. A home computer was a class of Personal computer entering the market in 1977 and becoming common during the 1980s A floppy disk is an increasingly Obsolete data storage medium that is composed of a disk of thin flexible ("floppy" Magnetic storage medium encased Even the first version of the IBM PC of 1981 had a cassette port and a command in its ROM BASIC programming language to use it. Microsoft BASICA (short for "Advanced BASIC" is a simple disk-based BASIC interpreter written by Microsoft for PC-DOS However, this was seldom used, as even then floppy drives had become commonplace in high-end machines.

The typical encoding method for computer data was simple FSK which resulted in typical data rates of 500 to 2000 bit/s, although some games used special faster loading routines, up to around 4000-bit/s. Frequency-shift keying (FSK is a Frequency modulation scheme in which digital information is transmitted through discrete frequency changes of a Carrier wave In Telecommunications and Computing, bitrate (sometimes written bit rate, data rate or as a Variable R or f b A rate of 2000-bit/s equates to a capacity of around 660 kilobytes per side of a 90-minute tape. A kilobyte (derived from the SI prefix Kilo -, meaning 1000 is a unit of Information or Computer storage equal to either 1024

Among home computers that primarily used data cassettes for storage in the late 1970s were Commodore PET (early models of which had a cassette drive built-in), TRS-80 and Apple II Plus, until the introduction of floppy disc drives and hard drives in the early 1980s made cassettes virtually obsolete for day-to-day use in the US. The PET ( P ersonal E lectronic T ransactor) was a home -/ Personal computer produced by Commodore starting in 1977 TRS-80 was Tandy Corporation 's desktop Microcomputer model line sold through Tandy's Radio Shack stores in the late 1970s and early The Apple II Plus was the second model of the Apple II series of Personal computers produced by Apple Computer Inc A floppy disk is an increasingly Obsolete data storage medium that is composed of a disk of thin flexible ("floppy" Magnetic storage medium encased A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device However, they remained in use on some portable systems such as the TRS-80 Model 100 line until the early 1990s. The TRS-80 Model 100 Portable computer was introduced in 1983 Due to the high price of disks, cassettes also remained the primary data storage medium for 8-bit computers in many countries (for example, the UK, where 8-bit software was mostly sold on cassette until that market disappeared altogether in the early 1990s. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located )

In some countries, including Scotland, Poland and the Netherlands, audio cassette data storage was so popular that some radio stations would broadcast computer programs that listeners could record onto cassette and then load into their computer. Scotland ( Gaelic: Alba) is a Country in northwest Europethat occupies the northern third of the island of Great Britain. Poland (Polska officially the Republic of Poland The Netherlands ( Dutch:, ˈnedərlɑnt is the European part of the Kingdom of the Netherlands, which consists of the Netherlands the Netherlands ^[21] See BASICODE. BASICODE was a computer project intended to create a unified standard for the BASIC Programming language.

The use of better modulation techniques like QPSK or those used in modern modems, combined with the improved bandwidth and signal to noise ratio of newer cassette tapes, allowed much greater capacities (up to 60 MB) and speeds (10–17 kB/s for data rate) on each cassette. In Telecommunications, modulation is the process of varying a periodic Waveform, i Phase-shift keying (PSK is a Digital Modulation scheme that conveys data by changing or modulating the phase of a reference signal Modem (from mo dulator- dem odulator is a device that modulates an analog carrier signal to encode Digital information Bandwidth is the difference between the upper and lower Cutoff frequencies of for example a filter, a Communication channel, or a Signal spectrum Signal-to-noise ratio (often abbreviated SNR or S/N) is an Electrical engineering concept also used in other fields (such as scientific Measurements A megabyte is a unit of Information or Computer storage equal to either 106 (1000000 Bytes or 220 (1048576 bytes depending on These were typically used as hard disk backup for PCs in the late 1980s. A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device A personal computer ( PC) is any Computer whose original sales price size and capabilities make it useful for individuals and which is intended to be operated They also found use during the 1980s in data loggers for scientific and industrial equipment. A data logger (also datalogger or data recorder) is an electronic device that records data over time or in relation to location either with a built in instrument

Successors

A Compact Cassette and a microcassette

Technical development of the cassette effectively ceased when digital recordable media such as DAT and MiniDisc were introduced in the late 1980s and early 1990s. Digital Audio Tape (DAT or R-DAT is a signal recording and playback medium developed by Sony in the mid 1980s A MiniDisc ( MD) is a Magneto-optical disc-based Data storage device initially intended for storage of up to 80 minutes of digitized audio Anticipating the switch from analog to digital, major companies such as Sony shifted their focus to new media. ^[22] In 1992, Philips introduced the Digital Compact Cassette (DCC), a DAT-like tape in the same form factor as the compact audio cassette. Digital Compact Cassette ( DCC) is an obsolete Magnetic tape sound recording format introduced by Philips and Matsushita in late 1992 It was aimed primarily at the consumer market. A DCC deck could play back both types of cassettes. Unlike DAT, which was accepted in professional usage because it could record without lossy compression effects, DCC failed in both home and mobile environments, and was discontinued in 1996. ^[23]

The microcassette has in many cases supplanted the full-sized audio cassette in situations where voice-level fidelity is all that is required, such as in dictation machines and answering machines. A Microcassette (often written generically as microcassette) is an Audio storage medium introduced by Olympus in 1969. An answering machine, also known as an answerphone, ansaphone or ansafone (especially in UK and British commonwealth countries or telephone answering Even these, in turn, are starting to give way to digital recorders of various descriptions. ^[24] Since the rise of cheap CD-R discs, and flash memory-based digital audio players, the phenomenon of "home taping" has effectively switched to recording to Compact Disc or downloading from commercial or music sharing websites. A CD-R ( C ompact D isc- R ecordable is a variation of the Compact Disc invented by Philips and Sony. Flash memory is non-volatile computer memory that can be electrically erased and reprogrammed A digital audio player, more commonly referred to as an MP3 player, is a Consumer electronics device that stores organizes and plays audio files Some ^[25]

Because of consumer demand, the cassette has remained influential on design over a decade after its decline as a media mainstay. As the Compact Disc grew in popularity, cassette-shaped audio adapters were developed to provide an economical and clear way to obtain CD functionality in vehicles equipped with cassette decks. cassette adapter was invented to allow one to play music through Sound systems with a tape player but no auxiliary input A portable CD player would have its analog line-out connected to the adapter, which in turn fed the signal to the head of the cassette deck. These adapters continue to function with MP3 players as well, and are generally more reliable than the FM transmitters that must be used to adapt CD players to MP3s. A digital audio player, more commonly referred to as an MP3 player, is a Consumer electronics device that stores organizes and plays audio files Some MP3 players shaped as audio cassettes have also become available, which can be inserted into any tape player and communicate with the head as if they were normal cassettes. ^[26][27]

Repair

Cassettes contain moving parts such as rollers which can become worn, leading to jamming or breakage of the magnetic tape itself. This need not spell the end of a valuable recording: one can extract the tape from the shell of its cartridge and transplant it into a new cartridge. "Eaten" tapes as described above can in many cases also be rescued after running the tapes' back side over a rounded surface such as a pen to re-flatten it as best as possible. A crude repair can even be performed on a severed tape by carefully aligning and reattaching the strand ends against a backing of special mylar splicing tape (normal adhesive tape should never be used on audio recording tape because the adhesive will "bleed" over time), then trimming excess on either side with scissors or a precision knife, enabling a basic playback such as for dubbing out to another recording device. Adhesive tape can be one of many varieties of backing materials coated with an Adhesive.

Better-made compact cassettes are held together by a number of screws, so that they may be disassembled and reassembled. It may be helpful to practice the procedure on blank cassettes first. Care should be taken to ensure that the tape follows the correct path through the cassette before reassembly, and that all of the small parts are in their proper places. If the original, worn cassette is glued together instead of held together by screws, it can be cracked progressively open by inserting a thin blade of metal (such as a screwdriver or knife blade) in the seam between the halves of the cassette shell, while exercising care not to gouge or damage the reels.

The spools upon which the tape is wound are often slotted so that the end of the tape may be freed from one spool and secured to a new spool.

Two other common problems with cassette tapes are: 1) the tape winds unevenly inside the plastic case over time which gives rise to jamming during playback or rewinding, and 2) the felt pressure pad that contacts the magnetic tape eventually falls off. Two solutions: 1) slap the cassette on a flat surface several times and then rewind the tape all the way through without pause (this may have to be tried several times). 2) replace the part composed of the copper and felt pressure pad unit from an unused cassette tape.

See also

• Cassette culture
• Cassette single
• Compact Disc player
• Digital cassettes
• 8-track cartridge
• Elcaset
• Electronic journalism
• Home Taping is Killing Music
• List of audio formats
• Microcassette
• Minicassette
• Mix tape
• Pocket Rockers
• PXL-2000
• VHS

References

External links

• Photos of many brands of cassettes
• Reviews and comparisons of various cassette types
• AudioTools - Cassette Tape reference
• Technical data and photographs of vintage cassette decks
• A brief history of the recording media industry
• Discography showing example of One Plus One cassette
• Tape recording and playback concepts