1.
Equalization (audio)
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Equalization is the process of adjusting the balance between frequency components within an electronic signal. The most well known use of equalization is in recording and reproduction but there are many other applications in electronics. The circuit or equipment used to achieve equalization is called an equalizer and these devices strengthen or weaken the energy of specific frequency bands or frequency ranges. In sound recording and reproduction, equalization is the commonly used to alter the frequency response of an audio system using linear filters. Most hi-fi equipment uses relatively simple filters to make bass and treble adjustments, graphic and parametric equalizers have much more flexibility in tailoring the frequency content of an audio signal. An equalizer is the circuit or equipment used to achieve equalization, since equalizers, adjust the amplitude of audio signals at particular frequencies, they are, in other words, frequency-specific volume knobs. The term EQ specifically refers to this variant of the term, stereos and basic guitar amplifiers typically have adjustable equalizers which boost or cut bass or treble frequencies. Mid- to high-priced guitar and bass amplifiers usually have more bands of frequency control, such as bass, mid-range and treble or bass, low-mid, high-mid, some amps have an additional knob for controlling very high frequencies. Broadcast and recording studios use sophisticated equalizers capable of more detailed adjustments. The most common equalizers in music production are parametric, semi-parametric, graphic, peak, graphic equalizers are often included in consumer audio equipment and software which plays music on home computers. Parametric equalizers require more expertise than graphic equalizers, and they can provide more specific compensation or alteration around a chosen frequency and this may be used in order to remove unwanted resonances or boost certain frequencies. An acoustic guitarist who finds that her instrument sounds too boomy may ask the engineer to reduce the low frequency range response. A guitarist who finds that the instrument sound in the PA has too much finger noise may ask the engineer to reduce the frequency range response. The concept of equalization was first applied in correcting the frequency response of telephone lines using passive networks, a plot of the systems net frequency response would be flat, as its response to all frequencies would literally be equal. Much later the concept was applied in engineering to adjust the frequency response in recording, reproduction. Audio amplifiers have long had filters or controls to modify their frequency response and these are most often in the form of variable bass and treble controls, and switches to apply low-cut or high-cut filters for elimination of low frequency rumble and high frequency hiss respectively. Graphic equalizers and other equipment developed for improving fidelity have since used by recording engineers to modify frequency responses for aesthetic reasons. Hence in the field of audio electronics the term equalization is now used to describe the application of such filters regardless of intent
2.
Fade (audio engineering)
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In audio engineering, a fade is a gradual increase or decrease in the level of an audio signal. The term can also be used for film cinematography or theatre lighting in much the same way, a recorded song may be gradually reduced to silence at its end, or may gradually increase from silence at the beginning. Fading-out can serve as a solution for pieces of music that contain no obvious ending. Both fades and cross-fades are very valuable since they allow the engineer to quickly and easily make sure that the beginning and it is necessary that there is a clear section of silence prior to the audio. Fade-ins and out can also be used to change the characteristics of a sound, for example a fade-in is used to soften the attack and it can also be used to soften up the attack of the drum and/or percussion instruments. A cross-fade can be manipulated through its rates and coefficients in order to create different styles of fading, almost every fade is different, this means that the fade parameters must be adjusted according to the individual needs of the mix. Club DJs in house music and techno use DJ mixers, two or more sound sources along with a skill called beatmatching to make seamless dance mixes for dancers at raves, nightclubs, though relatively rare, songs can fade out then fade back in. 2 by Argent and Future by Paramore, possibly the earliest example of a fade-out ending can be heard in Joseph Haydns Symphony No. 45, nicknamed the Farewell Symphony on account of the fade-out ending and this was expressed by the players extinguishing their stand candles and leaving the stage one by one during the final adagio movement of the symphony, leaving only two muted violins playing. Esterhazy appears to have understood the message, allowing the musicians to leave, gustav Holsts Neptune, the mystic, part of the orchestral suite The Planets written between 1914 and 1916, is another early example of music to have a fade-out ending during performance. Until the imagination knew no difference between sound and silence, the technique of ending a spoken or musical recording by fading out the sound goes back to the earliest days of recording. This is called the “Pulse Continuity Phenomenon and was measured by a task to measure participants’ perception of pulsation. An 189478 rpm record called The Spirit of 76, a narrated musical vignette with martial fife-and-drum that gets louder as it nears the listener and quieter as it moves away, there are early examples that appear to bear no obvious relationship to movement. One is Barkin Dog by the Ted Lewis Jazz Band, another contender is America, a patriotic piece by the chorus of evangelist Billy Sunday. By the early 1930s longer songs were being put on both sides of records, with the fading out at the end of Side One. Records at the time only about two to five minutes of music per side. The segue allowed for longer songs, symphonies and live concert recordings, however, shorter songs continued to use the fade-out for unclear reasons—for example, Fred Astaires movie theme Flying Down to Rio. Even using fade-out as a segue device doesnt seem obvious, though we certainly take it for granted today and it is possible that movies were an influence here
3.
Mixing console
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In the 2010s, a mixer is able to control analog or digital signals, depending on the type of mixer. The modified signals are summed to produce the output signals. A typical, simple application combines signals from two microphones into an amplifier that drives one set of speakers simultaneously, a DJ mixer may have only two channels, for mixing two record players. A coffeehouses tiny stage might only have a six channel mixer, a nightclub stages mixer for rock music shows may have 24 channels for mixing the signals from a rhythm section, lead guitar and several vocalists. A mixing console for a large concert may have 48 channels, a mixing console in a professional recording studio may have as many as 96 channels. In practice, mixers do more than simply mix signals, some mixers have onboard electronic effects, such as reverb. Some mixers intended for small venue live performance applications may include a power amplifier. A mixing console is also known as a mixer, audio console, mixing desk, sound mixer, sound board. A typical analog mixing board has three sections, Channel inputs Master controls Audio level metering The channel input strips are usually a bank of identical monaural or stereo input channels. Each channel has rotary knobs, buttons and/or faders for controlling the gain, the master control section is used to adjust the levels of the overall output of the mixer. The master control section has sub-group faders, master faders, master auxiliary mixing bus level controls, in addition it may have solo monitoring controls, a stage talk-back microphone control, muting controls and an output matrix mixer. On smaller mixers the inputs are on the left of the mixing board, in larger mixers, the master controls are in the center with input faders and channel strips on both sides. The audio level meters may be above the input and master sections or they may be integrated into the input, the audio level meters indicate when the signals are clipping. Each signal that is plugged into the mixer has its own channel, depending on the specific mixer, each channel is stereo or monaural. On most mixers, each channel has an XLR input, the smallest, least expensive mixers may only have one XLR input with the other inputs being line inputs. These can be used by a singer-guitarist or other small acts, below each input, there are usually several rotary controls. The first knob is typically a trim or gain control, the inputs buffer the signal from the external device and this controls the amount of amplification or attenuation needed to bring the signal to a nominal level for processing. This stage is where most noise of interference is picked up, balanced inputs and connectors, such as XLR or phone connectors, reduce interference problems
4.
DJ
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A disc jockey is a person who mixes different sources of pre-existing recorded music as it is playing, usually for a live audience in a nightclub or dance club or via broadcasting. DJs typically perform for an audience in a nightclub or dance club or a TV, radio broadcast audience, or in the 2010s. DJs also create mixes, remixes and tracks that are recorded for later sale, in hip hop music, DJs may create beats, using percussion breaks, basslines and other musical content sampled from pre-existing records. In hip hop, rappers and MCs use these beats to rap over, DJs use equipment that can play at least two sources of recorded music simultaneously and mix them together. This allows the DJ to create seamless transitions between recordings and develop unique mixes of songs, DJ equipment, notably the specialized DJ mixer, a small audio mixer with a crossfader and cue functions. The crossfader enables the DJ to blend or transition from one song to another, the cue knobs or switches allow the DJ to preview a source of recorded music in headphones before playing it for the live club or broadcast audience. Previewing the music in headphones helps the DJ pick the track they want to play. DJs may also use a microphone to speak to the audience, effects such as reverb to create sound effects, drum machines. The title DJ is also used by DJs in front of their real names or adopted pseudonyms or stage names as a title to denote their profession. Some DJs focus on creating a mix of songs for the club dancers or radio audience. Other DJs use turntablism techniques such as scratching, in which the DJ or turntablist manipulates the record player turntable to create new sounds. In many types of DJing, including club DJing and radio/TV DJing, there are several types of disc jockey. Radio DJs or radio personalities introduce and play music that is broadcast on AM, FM, club DJs select and play music in bars, nightclubs or discothèques, or at parties, raves, or even in stadiums. Mobile DJs travel with portable sound systems and play recorded music at a variety of events. Some mobile DJs also serve as the master of ceremonies at weddings or other events, directing the attention of attendees, there are also many competitions for DJs that specialize in different turntablism techniques, such as mixing, hip hop music-style scratching or other kinds of techniques. Other types of DJ use musical performance techniques that allow them to be categorized as performing musicians, hip hop DJs and are also often songwriters or music producers who use turntablism and sampling to create backing instrumentals for new tracks. In reggae, the DJ is a vocalist who raps, toasts, chants or chats over pre-recorded rhythm tracks, the individual who helps the DJ by selecting tracks or records to be played is called the selector. Many electronica artists and producers who work as DJs often perform music by combining turntablism with keyboards, digital musical instruments
5.
Turntablism
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The mixer is plugged into a PA system for live events and/or broadcasting equipment (if the DJ is performing on radio, TV or Internet radio, so that a wider audience can hear the turntablists music. Turntablists typically use two or more turntables and headphones to cue up desired start points on different records, the word turntablist was originated by Luis DJ Disk Quintanilla. The new term coincided with the resurgence of hip-hop DJing in the 1990s, some turntablists use turntable techniques like beat mixing/matching, scratching, and beat juggling. Some turntablists seek to have recognized as traditional musicians capable of interacting and improvising with other performers. The use of the turntable as an instrument has its roots dating back to the 1930s, 1940s. Experimental composers used them to sample and create music that was produced by the turntable. Cages Imaginary Landscape No.1 is composed for two variable speed turntables, frequency recordings, muted piano and cymbal, edgard Varèse experimented with turntables even earlier in 1930, though he never formally produced any works using them. Examples of turntable effects can also be found on popular records produced in the 1960s and 1970s, creedence Clearwater Revivals 1968 self-titled debut album features a backspin effect in the song Walk on the Water. However, turntablism as it is known today did not surface until the development of hip hop in the late 1970s, Turntablism as a modern art form and musical practice has its roots within African-American inner city hip hop and hip hop culture of the late 1970s. Kool DJ Herc, Afrika Bambaataa and Grandmaster Flash are widely credited for having cemented the now established role of DJ as hip hops foremost instrumentalist. Kool Hercs invention of break-beat DJing is generally regarded as the development in hip hop history. His influence on the concept of DJ as turntablist is equally profound, to understand the significance of this achievement, it is important to first define the break. Briefly, the break of a song is a musical fragment only seconds in length, Kool Herc introduced the break-beat technique as a way of extending the break indefinitely. This is done by buying two of the record, finding the break on each record, and switching from one to the other using the DJ mixer. Using that idea, Grandmaster Flash elaborated on Kool Hercs invention of break-beat DJing and came up with the quick-mix theory and he described it as being. like cutting, the backspin, and the double-back. Kool Hercs revolutionary techniques set the course for the development of turntablism as an art form in significant ways, most important, however, he developed a new form of DJing that did not consist of just playing and mixing records one after the other. The type of DJ that specializes in mixing a set is well respected for his/her own set of unique skills, the DJ would be examined critically by the crowd on both a technical and entertainment level. Grand Wizzard Theodore, an apprentice of Flash, who isolated the most recognizable technique of turntablism, [ Eshun
6.
Phonograph
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The phonograph is a device invented in 1877 for the mechanical recording and reproduction of sound. In its later forms it is called a gramophone. To recreate the sound, the surface is rotated while a playback stylus traces the groove and is therefore vibrated by it. In later electric phonographs, the motions of the stylus are converted into an electrical signal by a transducer. The phonograph was invented in 1877 by Thomas Edison, while other inventors had produced devices that could record sounds, Edisons phonograph was the first to be able to reproduce the recorded sound. His phonograph originally recorded sound onto a sheet wrapped around a rotating cylinder. A stylus responding to sound vibrations produced an up and down or hill-and-dale groove in the foil, in the 1890s, Emile Berliner initiated the transition from phonograph cylinders to flat discs with a spiral groove running from the periphery to near the center. Later improvements through the years included modifications to the turntable and its system, the stylus or needle. The disc phonograph record was the dominant audio recording format throughout most of the 20th century, from the mid-1980s on, phonograph use on a standard record player declined sharply because of the rise of the cassette tape, compact disc and other digital recording formats. Records are still a favorite format for some audiophiles and DJs, vinyl records are still used by some DJs and musicians in their concert performances. Musicians continue to release their recordings on vinyl records, the original recordings of musicians are sometimes re-issued on vinyl. Usage of terminology is not uniform across the English-speaking world, in more modern usage, the playback device is often called a turntable, record player, or record changer. When used in conjunction with a mixer as part of a DJ setup, the term phonograph was derived from the Greek words φωνή and γραφή. The similar related terms gramophone and graphophone have similar root meanings, the roots were already familiar from existing 19th-century words such as photograph, telegraph, and telephone. In British English, gramophone may refer to any sound-reproducing machine using disc records, the term phonograph was usually restricted to machines that used cylinder records. Gramophone generally referred to a wind-up machine, after the introduction of the softer vinyl records, 33 1⁄3-rpm LPs and 45-rpm single or two-song records, and EPs, the common name became record player or turntable. Often the home record player was part of a system that included a radio and, later, from about 1960, such a system began to be described as a hi-fi or a stereo. In American English, phonograph, properly specific to machines made by Edison, was used in a generic sense as early as the 1890s to include cylinder-playing machines made by others
7.
Disco
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Disco is a genre of dance music containing elements of funk, soul, pop, and salsa. It achieved popularity during the mid-1970s to the early 1980s, Disco can be seen as a reaction against both the domination of rock music and the stigmatization of dance music by the counterculture during this period. It was popular with men and women, from many different backgrounds. The disco sound often has several components, a beat, an eighth note or 16th note hi-hat pattern with an open hi-hat on the off-beat. In most disco tracks, string sections, horns, electric piano, Orchestral instruments such as the flute are often used for solo melodies, and lead guitar is less frequently used in disco than in rock. Many disco songs use electronic synthesizers, particularly in the late 1970s, well-known 1970s disco performers included Donna Summer, the Bee Gees, Boney M. KC and the Sunshine Band, The Trammps, Sylvester, Village People, Gloria Gaynor and Chic. While performers and singers garnered much attention, record producers working behind the scenes played an important role in developing the disco sound. Many non-disco artists recorded songs at the height of discos popularity. Disco was the last mass popular movement that was driven by the baby boom generation. Disco was a phenomenon, but its popularity drastically declined in the United States in 1980. Disco Demolition Night, an anti-disco protest held in Chicago on 12 July 1979, is thought of as a factor in discos fast. By the late 1970s most major U. S. cities had thriving disco club scenes, Studio 54, a venue popular amongst celebrities, is a well-known example of a disco club. Popular dances included the Hustle, a suggestive dance. Discotheque-goers often wore expensive, extravagant and sexy fashions, Disco clubs were also associated with promiscuity. Disco was a key influence on the 1980s electronic dance style called house. The term is derived from discothèque, by the early 1940s, the terms disc jockey and DJ were in use to describe radio presenters. During WWII, because of restrictions set in place by the Nazi occupiers, eventually more than one of these jazz venues had the proper name discothèque. By 1959, the term was used in Paris to describe any of these type of nightclubs and that year a young reporter named Klaus Quirini started to select and introduce records at the Scotch-Club in Aachen, West Germany
8.
House music
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House music is a genre of electronic music created by club DJs and music producers in Chicago in the early 1980s. Early house music was characterized by repetitive 4/4 beats, rhythms mainly provided by drum machines, off-beat hi-hat cymbals. While house displayed several characteristics similar to music, it was more electronic and minimalistic. House music became popular in Chicago clubs in 1984 and it was pioneered by figures such as Frankie Knuckles, Phuture, Kym Mazelle, and Mr. Fingers, and was associated with African-American and gay subcultures. House music quickly spread to other American cities such as Detroit, New York City, Baltimore, in the mid-to-late 1980s, house music became popular in Europe as well as major cities in South America, and Australia. Since the early to mid-1990s, house music has been infused in mainstream pop, in the late 1980s, many local Chicago house music artists suddenly found themselves presented with major label deals. House music proved to be a successful genre and a more mainstream pop-based variation grew increasingly popular. House music has also fused with other genres creating fusion subgenres, such as euro house, tech house, electro house. After enjoying significant success in the early to mid-90s, house music grew even larger during the wave of progressive house. The genre has remained popular and fused into other subgenres, for example, ghetto house, deep house. As of 2016, house music popular in both clubs and in the mainstream pop scene while retaining a foothold on underground scenes across the globe. The song structure of music songs typically involves an intro, a chorus, various verse sections, a midsection. Some songs do not have a verse, taking a part from the chorus. The drum beat is one of the important elements within the genre and is almost always provided by an electronic drum machine rather than by a human drummer playing drumkit. The drum beats of house are four on the floor, with bass drums played on every beat, House music is often based on bass-heavy loops or basslines produced by a synthesizer and/or from samples of disco or funk songs. The tempo of most house songs is between 118 and 135 beats per minute, soul music and disco influenced house music. These artists produced longer, more repetitive, and percussive arrangements of existing disco recordings, early house producers such as Frankie Knuckles created similar compositions from scratch, using samplers, synthesizers, sequencers, and drum machines. Rachel Cain, co-founder of an influential Trax Records, was involved in the burgeoning punk scene and cites industrial
9.
Electronic dance music
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Electronic dance music is a broad range of percussive electronic music genres made largely for nightclubs, raves, and festivals. EDM is generally produced for playback by disc jockeys who create seamless selections of tracks, called a mix, EDM producers also perform their music live in a concert or festival setting in what is sometimes called a live PA. In the United Kingdom and in continental Europe, EDM is more commonly called dance music or simply dance. In the late 1980s and early 1990s, following the emergence of raving, pirate radio, at this time a perceived association between EDM and drug culture led governments at state and city level to enact laws and policies intended to halt the spread of rave culture. By the early 2010s the term dance music and the initialism EDM was being pushed by the US music industry. Early examples of dance music include the disco music of Giorgio Moroder. During the early 1980s, the popularity of disco music declined in the United States, abandoned by major US record labels. European disco continued evolving within the mainstream pop music scene. European acts Silver Convention, Love and Kisses, Munich Machine, and American acts Donna Summer, in 1977, Giorgio Moroder and Pete Bellotte produced I Feel Love for Donna Summer. It became the first well-known disco hit to have a completely synthesised backing track, other disco producers, most famously American producer Tom Moulton, grabbed ideas and techniques from dub music to provide alternatives to the four on the floor style that dominated. The sound that originated from P-Funk the electronic side of disco, dub music. Much of the music produced during this time was, like disco, at this time creative control started shifting to independent record companies, less established producers, and club DJs. Other dance styles that began to become popular during the era include dance-pop, boogie, electro, Italo disco, house. In the early 1980s, electro emerged as a fusion of funk, also called electro-boogie, but later shortened to electro, cited pioneers include Zapp, D. Train, Sinnamon. Early hip hop and rap combined with German and Japanese electropop influences such as Kraftwerk, as the electronic sound developed, instruments such as the bass guitar and drums were replaced by synthesizers and most notably by iconic drum machines, particularly the Roland TR-808. Early uses of the TR-808 include several Yellow Magic Orchestra tracks in 1980-1981, the 1982 track Planet Rock by Afrikaa Bambaataa, and the 1982 song Sexual Healing by Marvin Gaye. In 1982, producer Arthur Baker with Afrika Bambaataa released the seminal Planet Rock which was influenced by the Yellow Magic Orchestra using Kraftwerk samples, Planet Rock was followed later that year by another breakthrough electro record, Nunk by Warp 9. In 1983, Hashim created an electro funk sound which influenced Herbie Hancock, the early 1980s were electros mainstream peak
10.
Sound recording and reproduction
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Sound recording and reproduction is an electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording, prior to the development of analog recording, there were mechanical systems for reproducing instrumental music, such as wind-up music boxes and later, in the late 19th century, player pianos. Analog sound reproduction is the process, with a bigger loudspeaker diaphragm causing changes to atmospheric pressure to form acoustic sound waves. Digital recording and reproduction converts the sound signal picked up by the microphone to a digital form by the process of digitization. This lets the audio data be stored and transmitted by a variety of media. Whereas successive copies of an analog recording tend to degrade in quality, as noise is added. A digital audio signal must be reconverted to analog form during playback before it is amplified and connected to a loudspeaker to produce sound, long before sound was first recorded on cylinders or records, music was recorded—first by written music notation, then also by mechanical devices. Fowler, this. cylinder with raised pins on the surface remained the device to produce and reproduce music mechanically until the second half of the nineteenth century. The Banu Musa brothers also invented an automatic flute player, which appears to have been the first programmable machine, according to Fowler, the automata were a robot band that performed. more than fifty facial and body actions during each musical selection. In the 14th century, Flanders introduced a mechanical bell-ringer controlled by a rotating cylinder, similar designs appeared in barrel organs, musical clocks, barrel pianos, and musical boxes. A music box is a musical instrument that produces sounds by the use of a set of pins placed on a revolving cylinder or disc so as to pluck the tuned teeth of a steel comb. They were developed from musical snuff boxes of the 18th century, some of the more complex boxes also have a tiny drum and/or bells, in addition to the metal comb. The fairground organ, developed in 1892, used a system of accordion-folded punched cardboard books, the player piano, first demonstrated in 1876, used a punched paper scroll that could store an long piece of music. The most sophisticated of the rolls were hand-played, meaning that the roll represented the actual performance of an individual. This technology to record a live performance onto a piano roll was not developed until 1904, piano rolls were in continuous mass production from 1896 to 2008. A1908 U. S. Supreme Court copyright case noted that, in 1902 alone, the use of piano rolls began to decline in the 1920s although one type is still being made today. The first device that could record actual sounds as they passed through the air was the phonautograph, the earliest known recordings of the human voice are phonautograph recordings, called phonautograms, made in 1857. They consist of sheets of paper with sound-wave-modulated white lines created by a stylus that cut through a coating of soot as the paper was passed under it
11.
Compact Cassette
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The Compact Cassette or Musicassette, also commonly called cassette tape, audio cassette, or simply tape or cassette, is an analog magnetic tape recording format for audio recording and playback. It was released by Philips in 1962, having developed in Hasselt. Compact cassettes come in two forms, either already containing content as a cassette, or as a fully recordable blank cassette. Its uses ranged from portable audio to home recording to data storage for early microcomputers, the first cassette player designed for use in car dashes was introduced in 1968. Between the early 1970s and the early 2000s, the cassette was one of the two most common formats for prerecorded music, first alongside the LP record and later the compact disc. Compact Cassettes contain two miniature spools, between which a magnetically coated, polyester-type plastic film is passed and wound and these spools and their attendant parts are held inside a protective plastic shell. This reversal is achieved either by flipping the cassette, or by having the machine itself change the direction of tape movement. In 1935, decades before the introduction of the Compact Cassette, AEG released the first reel-to-reel tape recorder and it was based on the invention of the magnetic tape by Fritz Pfleumer, which used similar technology but with open reels. These instruments were expensive and relatively difficult to use and were therefore used mostly by professionals in radio stations. In 1958, following four years of development, RCA Victor introduced the stereo, quarter-inch, reversible, however, it was a large cassette, and offered few pre-recorded tapes. Despite the multiple versions, it failed, consumer use of tape only took off in the early 1960s, after playback machines reached a comfortable, user-friendly design. This was achieved primarily by the introduction of transistors which replaced the bulky, fragile, reel-to-reel tape then became more suitable to household use, but still remained an esoteric product. The team at Philips was led by Lou Ottens in Hasselt, Philips was competing with Telefunken and Grundig in a race to establish its cassette tape as the worldwide standard, and it wanted support from Japanese electronics manufacturers. However, the Philips Compact Cassette became dominant as a result of Philips decision to license the format free of charge, Philips also released the Norelco Carry-Corder 150 recorder/player in the US in November 1964. By 1966 over 250,000 recorders had been sold in the US alone, by 1968,85 manufacturers had sold over 2.4 million players. By the end of the 1960s, the business was worth an estimated 150 million dollars. In the early years sound quality was mediocre, but it improved dramatically by the early 1970s when it caught up with the quality of 8-track tape, the Compact Cassette went on to become a popular alternative to the 12-inch vinyl LP during the late 1970s. The mass production of blank Compact Cassettes began in 1964 in Hanover, prerecorded music cassettes were launched in Europe in late 1965
12.
CDJ
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A CDJ is a specialized digital music player for DJing. Originally designed to play music from compact discs, many CDJs can play music files stored on USB flash drives or SD cards. In typical use, at least two CDJs are plugged into a DJ mixer, CDJs have jog wheels and pitch faders that allow manipulation of the digital music file similar to a vinyl record on a DJ turntable. Many have additional features such as loops and beat analysis that are not present on turntables, additionally, some can function as DJ controllers to control the playback of digital files in DJ software running on a laptop instead of playing the files on the CDJ. The Pioneer CDJ-400, CDJ-800, CDJ-1000, CDJ-900, and the CDJ-2000 have a vinyl emulation mode that allows the operator to manipulate music on a CD as if it were on a turntable, models released prior to the CDJ-1000 lack this feature. Pioneer CDJs released after the CDJ-400 can play from USB sticks as well as CDs, Pioneer integrates its software rekordbox with the CDJs to prepare music with cue points, accurate BPM, and search/playlist functions. The CDJ-100S is a CDJ model that was released in the early 1998, the CDJ-100S is a basic CD player with a pitch controller and three sound effect options. The CDJ-200 is the budget model CDJ CD player released in 2004. It is similar in size to the CDJ-100S, however such as MP3 playback capabilities. Both the CDJ-100S and the CDJ-200 have similar options to manipulate the CD, the CDJ-400 was released in the late 2007. It is similar in size to the CDJ-200, but comes with scratching abilities and effects and this makes it possible to play MP3 music from a USB memory stick. On the back of the CDJ-400 is another USB connector that can be used to connect the CDJ-400 to a computer and this will enable the MIDI control possibilities so the player can be used to control various types of DJ mix software. The CDJ-400 has a built in USB sound card, the CDJ-500 was the first CDJ CD player released by Pioneer. The first Pioneer player to have a Jog Dial, allowing for cueing of the CD unlike rack-mounted CD players that were common at the time and it included a loop function, as well as loop-out adjust, and other facilities associated with looping samples from the track being played. The pitch control was +/- 10% only, and Master Tempo allowed the pitch to be locked despite tempo changes being made, all models of the 500 had top-opening CD loading, which is opposite to all the later ranges of CDJs which have since had front slot-loading of discs. Pioneer later released the CDJ-500II, with the changes being slightly faster performance, Loop Out adjustable. The CDJ-500S was a version of the CDJ-500. It marked the first inclusion of a system as well as front-loading of CDs
13.
Laptop
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Laptops are folded shut for transportation, and thus are suitable for mobile use. Although originally there was a distinction between laptops and notebooks, the former being bigger and heavier than the latter, as of 2014, there is often no longer any difference. Laptops are commonly used in a variety of settings, such as at work, in education, Internet surfing using sites such as YouTube and for personal multimedia, most 2016-era laptops also have integrated webcams and built-in microphones. Laptops can be powered either from a battery or by an external power supply from an AC adapter. Hardware specifications, such as the speed and memory capacity. Design elements, form factor, and construction can also vary significantly between models depending on intended use, as portable computers evolved into the modern laptop, they became widely used for a variety of purposes. The terms laptop and notebook are used interchangeably to describe a computer in English. Regardless of the etymology, by the late 1990s, the terms were interchangeable, as the personal computer became feasible in 1971, the idea of a portable personal computer soon followed. A personal, portable information manipulator was imagined by Alan Kay at Xerox PARC in 1968, the IBM Special Computer APL Machine Portable was demonstrated in 1973. This prototype was based on the IBM PALM processor, the IBM5100, the first commercially available portable computer, appeared in September 1975, and was based on the SCAMP prototype. As 8-bit CPU machines became widely accepted, the number of portables increased rapidly, the Osborne 1, released in 1981, used the Zilog Z80 and weighed 23.6 pounds. It had no battery, a 5 in CRT screen, in the same year the first laptop-sized portable computer, the Epson HX-20, was announced. The Epson had an LCD screen, a battery. Both Tandy/RadioShack and HP also produced portable computers of varying designs during this period, the first laptops using the flip form factor appeared in the early 1980s. The Dulmont Magnum was released in Australia in 1981–82, but was not marketed internationally until 1984–85, the US$8,150 GRiD Compass 1101, released in 1982, was used at NASA and by the military, among others. The Sharp PC-5000, Ampere and Gavilan SC released in 1983, the Gavilan SC was the first computer described as a laptop by its manufacturer, while the Ampere had a modern clamshell design. The Toshiba T1100 won acceptance not only among PC experts but the market as a way to have PC portability. From 1983 onward, several new techniques were developed and included in laptops, including the touchpad, the pointing stick
14.
Headphones
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Headphones are a pair of small electronic or electric listening devices that are designed to be worn on or around the head over a users ears. They are electroacoustic transducers, which convert a signal to a corresponding sound in the users ear. Headphones are designed to allow a user to listen to an audio source privately, in contrast to a loudspeaker. Headphones are also known as earspeakers, earphones or, colloquially, circumaural and supra-aural headphones use a band over the top of the head to hold the speakers in place. The other type, known as earbuds or earphones consist of units that plug into the users ear canal. In the context of telecommunication, a headset is a combination of headphone and microphone, the first headphones were developed in the late 1800s for use by telephone operators, to keep their hands free. Initially the audio quality was mediocre and a forward was the invention of high fidelity headphones. Headphones are made in a range of different audio reproduction quality capabilities, headsets designed for telephone use typically cannot reproduce sound with the high fidelity of expensive units designed for music listening by audiophiles. Headphones that use cables typically have either a 1/4 inch or 1/8 inch phone jack for plugging the headphones into the audio source, some stereo earbuds are wireless, using Bluetooth connectivity to transmit the audio signal by radio waves from source devices like cellphones and digital players. Due to the spread of wireless devices in recent years headphones are used by people in public places such as sidewalks, grocery stores. The latter two types of employees use headphones with an integrated microphone, Headphones originated from the earpiece, and were the only way to listen to electrical audio signals before amplifiers were developed. The first truly successful set was developed in 1910 by Nathaniel Baldwin, some very sensitive headphones, such as those manufactured by Brandes around 1919, were commonly used for early radio work. These early headphones used moving iron drivers, with either single ended or balanced armatures, the requirement for high sensitivity meant that no damping was used, thus the sound quality was crude. These early models lacked padding, and often produced excessive clamping forces on the wearers head and their impedance varied, headphones used in telegraph and telephone work had an impedance of 75 ohms. Those used with wireless radio had to be more sensitive and were made with more turns of finer wire. Impedance of 1000 to 2000 ohms was common, which suited both crystal sets and triode receivers, in early powered radios, the headphone was part of the vacuum tubes plate circuit and carried dangerous voltages. It was normally connected directly to the high voltage battery terminal. The use of electrical connections meant that users could be shocked if they touched the bare headphone connections while adjusting an uncomfortable headset
15.
Hip hop music
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It developed as part of hip hop culture, a subculture defined by four key stylistic elements, MCing/rapping, DJing/scratching with turntables, break dancing, and graffiti writing. Other elements include sampling beats or bass lines from records, while often used to refer solely to rapping, hip hop more properly denotes the practice of the entire subculture. Hip hops early evolution occurred as sampling technology and drum machines became available and affordable. Turntablist techniques such as scratching and beatmatching developed along with the breaks and Jamaican toasting, rapping developed as a vocal style in which the artist speaks or chants along rhythmically with an instrumental or synthesized beat. The Sugarhill Gangs 1979 song Rappers Delight is widely regarded to be the first hip hop record to gain popularity in the mainstream. The 1980s marked the diversification of hip hop as the genre developed more complex styles, prior to the 1980s, hip hop music was largely confined within the United States. However, during the 1980s, it began to spread to scenes in dozens of countries. New school hip hop was the wave of hip hop music, originating in 1983–84 with the early records of Run-D. M. C. The Golden age hip hop period was a period between the mid-1980s and the early 1990s. Notable artists from this era include the Juice Crew, Public Enemy, & Rakim, Boogie Down Productions and KRS-One, EPMD, Slick Rick, Beastie Boys, Kool G Rap, Big Daddy Kane, Ultramagnetic MCs, De La Soul, and A Tribe Called Quest. Gangsta rap is a subgenre of hip hop that often focuses on the violent lifestyles, in the West Coast hip hop style, G-funk dominated mainstream hip hop for several years during the 1990s. I. G. In the 1990s, hip hop began to diversify with other regional styles emerging, such as Southern rap, at the same time, hip hop continued to be assimilated into other genres of popular music, examples being Neo soul and nu metal. Hip hop became a pop music genre in the mid-1990s. The popularity of hip hop music continued through the 2000s, with hip hop influences also increasingly finding their way into mainstream pop, the United States also saw the success of regional styles such as crunk, a Southern genre that emphasized the beats and music more than the lyrics. Starting in 2005, sales of hip hop music in the United States began to severely wane, during the mid-2000s, alternative hip hop secured a place in the mainstream, due in part to the crossover success of artists such as OutKast and Kanye West. Creation of the hip hop is often credited to Keith Cowboy, rapper with Grandmaster Flash. However, Lovebug Starski, Keith Cowboy, and DJ Hollywood used the term when the music was known as disco rap. Cowboy later worked the hip hop cadence into a part of his stage performance, the first use of the term in print was in The Village Voice, by Steven Hager, later author of a 1984 history of hip hop
16.
Nu metal
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Nu metal is a form of alternative metal that combines elements of heavy metal music with elements of other music genres such as hip hop, alternative rock, funk and grunge. Nu metal bands have drawn elements and influences from a variety of musical styles, Nu metal rarely features guitar solos, the genre is heavily syncopated and based on guitar riffs. Many nu metal guitarists use seven-string guitars that are down-tuned to play a heavier sound, DJs are occasionally featured in nu metal to provide instrumentation such as sampling, turntable scratching and electronic backgrounds. Vocal styles in nu metal include singing, rapping, screaming and growling, Nu metal is one of the key genres of the New Wave of American Heavy Metal. Nu metal became popular in the late 1990s with bands and artists such as Korn, Limp Bizkit, Slipknot, many heavy metal fans have criticized nu metal, and do not regard it as true heavy metal. Many nu metal musicians have rejected the nu metal label and also have rejected being labeled as heavy metal, Nu metal is also known as nü-metal and aggro-metal. It is a subgenre of alternative metal, MTV states that the early nu metal group Korn arrived in 1993 into the burgeoning alternative metal scene, which would morph into nü-metal the way college rock became alternative rock. Stereogum has similarly claimed that nu metal was a outgrowth of the Lollapalooza-era alt-metal scene. Nu metal merges elements of metal music with elements of other music genres such as grunge, hip hop, funk. Nu metal bands also are influenced by and use elements of genres of metal music such as death metal, rap metal, groove metal, funk metal, alternative metal. Some nu metal bands such as Static-X and Dope made nu metal music elements of industrial metal. Nu metal music is heavily syncopated and is based mostly on guitar riffs, mid-song bridges and a general lack of guitar solos contrasts it with other genres of heavy metal. N its efforts to tune down and simplify riffs, nu-metal effectively drove a stake through the heart of the guitar solo. Another contrast with other metal genres is nu metals emphasis on rhythm, rather than on complexity or mood. The wah pedal is occasionally featured in nu metal music, Nu metal guitar riffs occasionally are similar to death metal guitar riffs. Nu metal bassists and drummers are often influenced by funk and hip hop, respectively, blast beats, which are common in heavy metal subgenres such as black metal and death metal, are extremely rare in nu metal. sound a Mack truck being crushed by a collapsing skyscraper. Some nu metal bands use seven-string guitars that are generally down-tuned, likewise, some bass guitarists use five-string and six-string instruments. Bass guitar-playing in nu metal often features an emphasis on elements such as slap bass, a percussive style of playing in which the thumb slaps the low strings
17.
Scratching
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Within hip hop culture, scratching is one of the measures of a DJs skills. In the 2010s, both scratching and scrubbing can be done on digital audio workstations which are equipped for these techniques, christian Marclay was one of the earliest musicians to scratch outside of hip hop. In the mid-1970s, Marclay used gramophone records and turntables as musical instruments to create sound collages and he developed his turntable sounds independently of hip hop DJs. Although he is little-known to mainstream audiences, Marclay has been described as the most influential turntable figure outside hip hop, in 1981 Grandmaster Flash released the song The Adventures of Grandmaster Flash on the Wheels of Steel which is notable for its use of many DJ scratching techniques. It was the first commercial recording produced entirely using turntables, in 1982, Malcolm McLaren & the Worlds Famous Supreme Team released a single Buffalo Gals, juxtaposing extensive scratching with calls from square dancing, and, in 1983, the EP, Dya Like Scratchin. Which is entirely focused on scratching, another 1983 release to prominently feature scratching is Herbie Hancocks Grammy Award-winning single Rockit. This song was performed live at the 1984 Grammy Awards, and in the documentary film Scratch. The Street Sounds Electro compilation series which started in 1983 is also notable for early examples of scratching, at the same time as the DJ is moving the record back and forth, the DJ manipulates the crossfader of a DJ mixer. This creates a rhythmic sound that has come to be one of the most recognizable features of hip hop music. Over time with excessive scratching, the stylus will cause what is referred to as record burn to a vinyl record, when scratching, this crossfader is utilized in conjunction with the scratching hand that is manipulating the record platter. The hand manipulating the crossfader is used to cut in and out of the records sound, using a digital vinyl system consists of playing vinyl discs on turntables whose contents is a timecode signal instead of a real music record. The turntables audio outputs are connected to the inputs of a computer audio interface. The audio interface digitizes the timecode signal from the turntables and transfers it to the computers DJ software, there is not a single standard of DVS, so that each form of DJ software has its own settings. Some DJ software such as Traktor Scratch Pro or Serato Scratch Live support only the audio interface sold with their software, Vinyl emulation software allows a DJ to manipulate the playback of digital music files on a computer via a DJ control surface. DJs can scratch, beatmatch, and perform other turntablist operations that cannot be done with a conventional keyboard, DJ software performing computer scratch operations include Traktor Pro, Mixxx, Serato Scratch Live & Itch, Virtual DJ, M-Audio Torq, DJay, Deckadance, Cross. DJs have also used tape, such as cassette or reel to reel to both mix and scratch. Tape DJing is rare, but Ruthless Ramsey in the US, Tj Scratchavite in Italy, Sounds that are frequently scratched include but are not limited to drum beats, horn stabs, spoken word samples, and vocals/lyrics from other songs. Some DJs and anonymous collectors release 12-inch singles called battle records that include trademark, the most recognizable samples used for scratching are the Ahh and Fresh samples, which originate from the song Change the Beat by Fab 5 Freddy
18.
Sound effect
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In motion picture and television production, a sound effect is a sound recorded and presented to make a specific storytelling or creative point without the use of dialogue or music. The term often refers to a process applied to a recording, in professional motion picture and television production, dialogue, music, and sound effects recordings are treated as separate elements. Dialogue and music recordings are never referred to as sound effects, even though the processes applied to such as reverberation or flanging effects, the term sound effect ranges back to the early days of radio. In its Year Book 1931 the BBC published an article about The Use of Sound Effects. It considers sounds effect deeply linked with broadcasting and states, It would be a mistake to think of them as anologous to punctuation marks. They should never be inserted into an already existing. The author of a broadcast play or broadcast construction ought to have used Sound Effects as bricks with which to build, treating them as of value with speech. If it fails to do so its presence could not be justified, the sound of people talking in the background is also considered a BG, but only if the speaker is unintelligible and the language is unrecognizable. These background noises are also called ambience or atmos, Foley sound effects are sounds that synchronize on screen, and require the expertise of a foley artist to record properly. Footsteps, the movement of hand props, and the rustling of cloth are common foley units, design sound effects are sounds that do not normally occur in nature, or are impossible to record in nature. These sounds are used to suggest futuristic technology in a fiction film. Each of these sound effect categories is specialized, with sound editors known as specialists in an area of sound effects, Foley is another method of adding sound effects. With this technique the action onscreen is essentially recreated to try to match it as closely as possible, if done correctly it is very hard for audiences to tell what sounds were added and what sounds were originally recorded. In the early days of film and radio, foley artists would add sounds in realtime or pre-recorded sound effects would be played back from analogue discs in realtime. Today, with effects held in digital format, it is easy to any required sequence to be played in any desired timeline. In the days of silent film, sound effects were added by the operator of an organ or photoplayer. Theater organ sound effects are usually electric or electro-pneumatic, and activated by a button pressed with the hand or foot, photoplayer operators activate sound effects either by flipping switches on the machine or pulling cow-tail pull-strings, which hang above. Sounds like bells and drums are made mechanically, sirens and horns electronically, due to its smaller size, a photoplayer usually has less special effects than a theater organ, or less complex ones
19.
Sound reinforcement system
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In both cases, these systems reinforce sound to make it louder or distribute it to a wider audience. Some audio engineers and others in the audio industry disagree over whether these audio systems should be called sound reinforcement systems or PA systems. Distinguishing between the two terms by technology and capability is common, while others distinguish by intended use, in some regions or markets, the distinction between the two terms is important, though the terms are considered interchangeable in many professional circles. These primary parts involve varying amounts of components to achieve the desired goal of reinforcing and clarifying the sound to the audience, performers. These signal inputs are plugged into the input jacks of a thick multicore cable, the snake then routes the signals of all of the inputs to either one or two mixing consoles. In these cases, at least two audio engineers are required, one to do the FOH Main mix and one to do the Monitor mix, once the signal arrives at a channel on the mixing console, this signal can be adjusted in many ways by the sound engineer. A signal can be equalized, compressed, or panned before being routed to an output bus. The signal may also be routed into an effects processor, such as a reverb effect, which outputs a wet version of the signal. Many electronic effects units are used in sound reinforcement systems, including digital delay, some concerts use pitch correction effects, which electronically correct any out-of-tune singing. A group of signals may be routed through a bus before being sent to the main bus to allow the engineer to control the levels of several related signals at once. A bus can often be processed just like an input channel. The mix of all the different signals and channels to the master faders on the console. Mixing consoles also have additional sends, also referred to as auxes or aux sends, on each channel so that a different mix can be created. One usage for aux sends is to create a mix of the vocal, another use of an aux send is to select varying amounts of certain channels, and then route these signals to an effects processor. A common example of the use of aux sends is to send all of the vocal signals from a rock band through a reverb effect. While reverb is usually added to vocals in the mix, it is not usually added to electric bass. The next step in the path generally depends on the size of the system in place. In smaller systems, the outputs are often sent to an additional equalizer, or directly to a power amplifier
20.
Nightclub
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A nightclub is an entertainment venue and bar which serves alcoholic beverages that usually operates late into the night. Another distinction is that whereas many pubs and sports bars aim at a market, nightclubs typically aim at a niche market of music and dancing enthusiasts. The upmarket nature of nightclubs can be seen in the inclusion of VIP areas in some nightclubs, for celebrities, nightclubs are much more likely than pubs or sports bars to use bouncers to screen prospective clubgoers for entry. Some nightclub bouncers do not admit people with ripped jeans or other clothing or gang apparel as part of a dress code. The busiest nights for a nightclub are Friday and Saturday night, most clubs or club nights cater to certain music genres, such as house music or gothic rock. A nightclub may also be called a discothèque, disco, or dance club, from about 1900 to 1920, working class Americans would gather at honky tonks or juke joints to dance to music played on a piano or a jukebox. Webster Hall is credited as the first modern nightclub, being built in 1886 and starting off as a hall, originally functioning as a home for dance. During Prohibition in the United States, nightclubs went underground as illegal speakeasy bars, with Webster Hall staying open, with rumors circulating of Al Capones involvement and police bribery. With the repeal of Prohibition in February 1933, nightclubs were revived, such as New Yorks 21 Club, Copacabana, El Morocco, in Germany, possibly the first discothèque was Scotch-Club. These discothèques were also patronized by anti-Vichy youth called zazous, there were also underground discothèques in Nazi Germany patronized by anti-Nazi youth called the swing kids. In Harlem, Connies Inn and the Cotton Club were popular venues for white audiences, before 1953 and even some years thereafter, most bars and nightclubs used a jukebox or mostly live bands. The Whisky à Gogo set into place the elements of the modern post World War II discothèque-style nightclub. At the end of the 1950s, several of the bars in Soho introduced afternoon dancing. In the early 1960s, Mark Birley opened a members-only discothèque nightclub, Annabels, in Berkeley Square, in 1962, the Peppermint Lounge in New York City became popular and is the place where go-go dancing originated. However, the first rock and roll generation preferred rough and tumble bars and taverns to nightclubs, disco has its roots in the underground club scene. It brought together people from all walks of life and backgrounds and these clubs acted as safe havens for homosexual partygoers to dance in peace and away from public scrutiny. Disco allowed patrons to explore sexuality and push the envelope on the dance floor, disco clubs acted as an escape from such depressing environments and acted as the fantasy marginalized peoples could escape to forget oppression and racism. Disco clubs originally functioned as liberated party spaces and were seen as places of political statement, a smooth mix of long single records to keep people dancing all night long
21.
Recording studio
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A recording studio is a facility for sound recording and mixing. Ideally both the recording and monitoring spaces are designed by an acoustician or audio engineer to achieve optimum acoustic properties. The engineers and producers listen to the music and the recorded tracks on monitor speakers and/or headphones. Major recording studios typically have a range of large, heavy, Isolation booths are small sound-insulated rooms with doors, designed for instrumentalists. This equipment may interfere with the recording process, Recording studios are carefully designed around the principles of room acoustics to create a set of spaces with the acoustical properties required for recording sound with precision and accuracy. This will consist of both room treatment and soundproofing to prevent sound from leaving the property. Even though sound isolation is a key goal, the musicians, singers, audio engineers and record producers still need to be able to see other, to see cue gestures. As such, the room, isolation booths, vocal booths. Some smaller studios do not have instruments, and bands and artists are expected to bring their own instruments, having musical instruments and equipment in the studio creates additional costs for a studio, as pianos have to be tuned and instruments need to be maintained. However, it makes it convenient for recording artists, as they do not have to bring in large. As well, less costly studio time is spent moving in gear, drummers bring their own snare drum, cymbals and sticks/brushes. The types and brands of equipment owned by a studio depends on the styles of music for the bands. A studio that mainly records heavy metal music will be likely to have large, powerful guitar amp heads, in contrast, a studio which mainly records country bands will likely have a selection of small, vintage combo amps. A studio that records a lot of 1970s-style funk may have an electric piano. General purpose computers have rapidly assumed a role in the recording process. A computer thus outfitted is called a Digital Audio Workstation, or DAW, other software applications include Ableton Live, Mixcraft, Cakewalk Sonar, ACID Pro, FL Studio, Adobe Audition, Auto-Tune, Audacity, and Ardour. While Apple Macintosh is used for most studio work, there is a breadth of available for Microsoft Windows. If no mixing console is used and all mixing is done using only a keyboard and mouse, the OTB is used when mixing with other hardware and not just the PC software
22.
Preamplifier
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Without this, the final signal would be noisy or distorted. They are typically used to amplify signals from analog sensors such as microphones, because of this, the preamplifier is often placed close to the sensor to reduce the effects of noise and interference. An ideal preamp will be linear, have input impedance. It is used to boost the strength to drive the cable to the main instrument without significantly degrading the signal-to-noise ratio. The noise performance of a preamplifier is critical, according to Friiss formula, when the gain of the preamplifier is high, the SNR of the final signal is determined by the SNR of the input signal and the noise figure of the preamplifier. Three basic types of preamplifiers are available, current-sensitive preamplifier parasitic-capacitance preamplifier charge-sensitive preamplifier, in an audio system, they are typically used to amplify signals from analog sensors to line level. The second amplifier is typically a power amplifier, the preamplifier provides voltage gain but no significant current gain. The power amplifier provides the current necessary to drive loudspeakers. For these systems some common sensors are microphones, instrument pickups, preamplifiers are often integrated into the audio inputs on mixing consoles, DJ mixers, and sound cards. They can also be stand-alone devices, the integrated pre-amplifier in a foil electret microphone. The first stages of an instrument amplifier, which is sent to the power amplifier. With instrument amplifiers, the preamp is often designed to produce overdrive or distortion effects, a stand-alone unit for use in live music and recording studio applications. As part of a stand-alone channel strip or channel strip built into a mixing desk. A masthead amplifier used with television receiver antenna or a satellite receiver dish, the circuit inside of a hard drive connected to the magnetic heads or the circuit inside of CD/DVD drive which connects to the photodiodes
23.
Public address system
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Simple PA systems are often used in small venues such as school auditoriums, churches, and small bars. Intercom systems, installed in buildings, have both speakers throughout a building, and microphones in many rooms allowing the occupants to respond to announcements. Sound reinforcement systems and PA systems may use some similar components, Sound reinforcement systems are for live music or performance, whereas PA systems are primarily for reproduction of speech. A short time later the Automatic Enunciator Company was established in Chicago in order to market the new device, in August 1912 a large outdoor installation was made at a water carnival held in Chicago by the Associated Yacht and Power Boat Clubs of America. Seventy-two loudspeakers were strung in pairs at intervals along the docks. The system was used to announce race reports and descriptions, carry a series of speeches about The Chicago Plan, and provide music between races. Four years later, in 1915, they built a dynamic loudspeaker with a 1-inch voice coil, a 3-inch corrugated diaphragm, the electromagnet created a flux field of approximately 11,000 G. Their first experiment used a carbon microphone, when the 12 V battery was connected to the system, they experienced one of the first examples of acoustic feedback. They then placed the loudspeaker on the roof, and claims say that the amplified human voice could be heard 1 mile away. Jensen and Pridham refined the system and connected a phonograph to the loudspeaker to be able to broadcast recorded music and this demonstration was official presentation of the working system, and approximately 100,000 people gathered to hear Christmas music and speeches with absolute distinctness. The first outside broadcast was one week later, again supervised by Jensen. Jensen oversaw the governor using the microphone while Pridham operated the loudspeaker, the following year, Jensen and Pridham applied for a patent for what they called their Sound Magnifying Phonograph. Over the next two years developed their first valve amplifier. In 1919 this was standardized as a 3-stage 25 watt amplifier, wilsons speech was part of his nationwide tour to promote the establishment of the League of Nations. It was held on September 9,1919 at City Stadium, as with the San Francisco installation, Jensen supervised the microphone and Pridham the loudspeakers. Wilson spoke into two large horns mounted on his platform which channelled his voice into the microphone, similar systems were used in the following years by Warren G. Harding and Franklin D. Roosevelt. By the early 1920s, Marconi had established a department dedicated to public address, in 1925, George V used such a system at the British Empire Exhibition, addressing 90,000 via six long-range loudspeakers. This public use of loudspeakers brought attention to the possibilities of such technology, the 1925 Royal Air Force Pageant at Hendon Aerodrome used a Marconi system to allow the announcer to address the crowds, as well as amplify the band
24.
DJ mix
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A DJ mix or DJ mixset is a sequence of musical tracks typically mixed together to appear as one continuous track. DJ mixing is significantly different from live sound mixing, remix services were offered beginning in the late 1970s in order to provide music which was more easily beatmixed by DJs for the dancefloor. One of the earliest DJs to refine their skills was DJ Kool Herc. Francis Grasso was the first DJ to use headphones and a form of mixing at the New York City nightclub Sanctuary. Upon its release in 2000, Paul Oakenfolds Perfecto Presents, Another World became the biggest selling DJ mix album in the US, a DJ mix is often put together with music from genres that fit into the more general term electronic dance music. Other genres mixed by DJ includes hip hop, breakbeat and disco, four on the floor disco beats can be used to create seamless mixes so as to keep dancers locked to the dancefloor. Two of main characteristics of music used in DJ mixes is a dominant bassline, music mixed by DJs usually has a tempo which ranges from 120 bpm up to 160 bpm. A DJ mixset is usually performed live in front of an audience in a nightclub, party, mixsets can also be performed live on radio or recorded in a studio. Methods of mixing vary slightly depending on the genres being played. House and trance DJs tend to aim for smooth blended mixes while hip-hop DJs may use turntablism, scratching, some DJs, particularly those mixing Goa trance may prefer to mix during a break in which instead of beats, washes of synthesized sounds are combined. Further refinement to the quality can be provided with harmonic mixing which avoids dissonant tones during a mix. In live situations, the progression of the DJ set is a dynamic process, the DJ chooses tracks partly in response to the activity on the dance floor. If the dance becomes less active, the DJ will make a judgement as to what track will increase dance floor activity. This may involve shifting the tempo or changing the mood of the set. Track choices are also due, in part, to where the DJ wishes to take his or her audience, in this way, the resulting mixset is brought about through a symbiotic relationship between audience and DJ. Studio DJs have the luxury of spending time on their mix. Traditional DJ mixing with vinyl required the DJ sync tracks tempo, DJs can use a mixers crossfader to switch between tracks or use the volume control for each source with the crossfader permanently positioned in the middle. Mixing is usually done through the use of headphones and a speaker or foldback as basic aids
25.
Effects unit
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An effects unit or pedal is an electronic or digital device that alters how a musical instrument or other audio source sounds. In the 2010s, most effects use solid state electronics and/or computer chips, some vintage effects units from the 1930s to the 1970s and modern reissues of these effects use mechanical components as well or vacuum tubes. Musicians, audio engineers and record producers use effects units during live performances or in the studio, typically with electric guitar, electronic keyboard, while guitar effects are most frequently used with electric or electronic instruments, effects can also be used with acoustic instruments, drums and vocals. Rackmounted or audio console-integrated reverb effects are used with vocals in live sound and sound recording. Examples of common units include wah-wah pedals, fuzzboxes and reverb units. A stompbox or pedal is a metal or plastic box placed on the floor in front of the musician and connected to the instrument. Pedals are usually the least expensive format, a rackmount device mounts on a standard 19-inch equipment rack and usually contains several types of effects. Rackmount effects typically have buttons and/or knobs on the face of the chassis for controlling the effects, an effects unit is also called an effect box, effects device, effects processor or simply effects. In audio engineer parlance, a signal without effects is dry, the abbreviation F/X or FX is sometimes used. A pedal-style unit may be called a box, stompbox. When a musician has multiple effects in a rack mounted road case, Effects units are available in a variety of formats or form factors. Stompboxes are usually the smallest, least expensive, and most rugged effects units, rackmount devices are generally more expensive and offer a wider range of functions. An effects unit can consist of analog or digital circuitry or a combination of the two, during a live performance, the effect is plugged into the electrical signal path of the instrument. In the studio, the instrument or other sound-sources auxiliary output is patched into the effect, form factors are part of a studio or musicians outboard gear. Stompboxes are small plastic or metal chassis which usually lie on the floor or in a pedalboard to be operated by the users feet, pedals are often rectangle-shaped, but there are a range of other shapes. Typical simple stompboxes have a single footswitch, one to three potentiometers for controlling the effect, and a single LED that indicates if the effect is on, depending on the type of pedal, the potentiometers may control different parameters of the effect. For a chorus effect, for example, the knobs may control the depth, some pedals have two knobs stacked on top of each other, enabling the unit to provide two knobs per single knob space. An effects chain or signal chain is formed by connecting two or more stompboxes, effect chains are typically created between the guitar and the amp or between the preamplifier and the power amp
26.
Reverberation
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Reverberation, in psychoacoustics and acoustics, is the persistence of sound after a sound is produced. This is most noticeable when the sound source stops but the reflections continue, decreasing in amplitude, until they reach zero amplitude. In comparison to an echo that is a minimum of 50 to 100 ms after the initial sound. As time passes, the amplitude of the reflections is reduced until it is reduced to zero, Reverberation is not limited to indoor spaces as it exists in forests and other outdoor environments where reflection exists. Reverberation occurs naturally when a person sings, talks or plays an instrument acoustically in a hall or performance space with sound-reflective surfaces. The sound of reverberation is often added to the vocals of singers in live sound systems. The time it takes for a signal to drop by 60 dB is the reverberation time, RT60 is the time required for reflections of a direct sound to decay 60 dB. Reverberation time is stated as a single value, if measured as a wide band signal, however, being frequency dependent. Being frequency dependent, the time measured in narrow bands will differ depending on the frequency band being measured. For precision, it is important to know what ranges of frequencies are being described by a time measurement. In the late 19th century, Wallace Clement Sabine started experiments at Harvard University to investigate the impact of absorption on the reverberation time. Using a portable wind chest and organ pipes as a sound source and he found that the reverberation time is proportional to room dimensions and inversely proportional to the amount of absorption present. The optimum reverberation time for a space in which music is played depends on the type of music that is to be played in the space, rooms used for speech typically need a shorter reverberation time so that speech can be understood more clearly. If the reflected sound from one syllable is still heard when the syllable is spoken. Cat, Cab, and Cap may all sound very similar, if on the other hand the reverberation time is too short, tonal balance and loudness may suffer. Reverberation effects are used in studios to add depth to sounds. Reverberation changes the perceived spectral structure of a sound, but does not alter the pitch, basic factors that affect a rooms reverberation time include the size and shape of the enclosure as well as the materials used in the construction of the room. Every object placed within the enclosure can also affect this time, including people
27.
USB
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It is currently developed by the USB Implementers Forum. USB was designed to standardize the connection of peripherals to personal computers. It has become commonplace on other devices, such as smartphones, PDAs, USB has effectively replaced a variety of earlier interfaces, such as serial ports and parallel ports, as well as separate power chargers for portable devices. Also, there are 5 modes of USB data transfer, in order of increasing bandwidth, Low Speed, Full Speed, High Speed, SuperSpeed, USB devices have some choice of implemented modes, and USB version is not a reliable statement of implemented modes. Modes are identified by their names and icons, and the specifications suggests that plugs, unlike other data buses, USB connections are directed, with both upstream and downstream ports emanating from a single host. This applies to power, with only downstream facing ports providing power. Thus, USB cables have different ends, A and B, therefore, in general, each different format requires four different connectors, a plug and receptacle for each of the A and B ends. USB cables have the plugs, and the corresponding receptacles are on the computers or electronic devices, in common practice, the A end is usually the standard format, and the B side varies over standard, mini, and micro. The mini and micro formats also provide for USB On-The-Go with a hermaphroditic AB receptacle, the micro format is the most durable from the point of view of designed insertion lifetime. The standard and mini connectors have a lifetime of 1,500 insertion-removal cycles. Likewise, the component of the retention mechanism, parts that provide required gripping force, were also moved into plugs on the cable side. A group of seven companies began the development of USB in 1994, Compaq, DEC, IBM, Intel, Microsoft, NEC, a team including Ajay Bhatt worked on the standard at Intel, the first integrated circuits supporting USB were produced by Intel in 1995. The original USB1.0 specification, which was introduced in January 1996, Microsoft Windows 95, OSR2.1 provided OEM support for the devices. The first widely used version of USB was 1.1, the 12 Mbit/s data rate was intended for higher-speed devices such as disk drives, and the lower 1.5 Mbit/s rate for low data rate devices such as joysticks. Apple Inc. s iMac was the first mainstream product with USB, following Apples design decision to remove all legacy ports from the iMac, many PC manufacturers began building legacy-free PCs, which led to the broader PC market using USB as a standard. The USB2.0 specification was released in April 2000 and was ratified by the USB Implementers Forum at the end of 2001.1 specification, the USB3.0 specification was published on 12 November 2008. Its main goals were to increase the transfer rate, decrease power consumption, increase power output. USB3.0 includes a new, higher speed bus called SuperSpeed in parallel with the USB2.0 bus, for this reason, the new version is also called SuperSpeed
28.
Sound card
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A sound card is an internal expansion card that provides input and output of audio signals to and from a computer under control of computer programs. The term sound card is applied to external audio interfaces used for professional audio applications. Sound functionality can also be integrated onto the motherboard, using components similar to found on plug-in cards. The integrated sound system is still referred to as a sound card. Most sound cards use a converter, which converts recorded or generated digital data into an analog format. The output signal is connected to an amplifier, headphones, or external device using standard interconnects, multichannel digital sound playback can also be used for music synthesis, when used with a compliance, and even multiple-channel emulation. This approach has become common as manufacturers seek simpler and lower-cost sound cards, most sound cards have a line in connector for an input signal from a cassette tape or other sound source that has higher voltage levels than a microphone. The sound card digitizes this signal, the DMAC transfers the samples to the main memory, from where a recording software may write it to the hard disk for storage, editing, or further processing. Another common external connector is the connector, for signals from a microphone or other low-level input device. Input through a microphone jack can be used, for example, an important sound card characteristic is polyphony, which refers to its ability to process and output multiple independent voices or sounds simultaneously. These distinct channels are seen as the number of audio outputs, sometimes, the terms voice and channel are used interchangeably to indicate the degree of polyphony, not the output speaker configuration. For example, many older sound chips could accommodate three voices, but only one channel for output, requiring all voices to be mixed together. Later cards, such as the AdLib sound card, had a 9-voice polyphony combined in 1 mono output channel, for some years, most PC sound cards have had multiple FM synthesis voices which were usually used for MIDI music. Modern low-cost integrated soundcards such as audio codecs like those meeting the AC97 standard and this is similar to the way inexpensive softmodems perform modem tasks in software rather than in hardware. Also, in the days of wavetable sample-based synthesis, some sound card manufacturers advertised polyphony solely on the MIDI capabilities alone. In this case, the output channel is irrelevant, typically. Instead, the polyphony measurement solely applies to the number of MIDI instruments the sound card is capable of producing at one given time, the final playback stage is performed by an external DAC with significantly fewer channels than voices. Connectors on the cards are color-coded as per the PC System Design Guide
29.
Microphone
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A microphone, colloquially nicknamed mic or mike, is a transducer that converts sound into an electrical signal. Several different types of microphone are in use, which employ different methods to convert the air pressure variations of a wave to an electrical signal. Microphones typically need to be connected to a preamplifier before the signal can be recorded or reproduced, in order to speak to larger groups of people, a need arose to increase the volume of the human voice. The earliest devices used to achieve this were acoustic megaphones, some of the first examples, from fifth century BC Greece, were theater masks with horn-shaped mouth openings that acoustically amplified the voice of actors in amphitheatres. In 1665, the English physicist Robert Hooke was the first to experiment with an other than air with the invention of the lovers telephone made of stretched wire with a cup attached at each end. German inventor Johann Philipp Reis designed an early sound transmitter that used a strip attached to a vibrating membrane that would produce intermittent current. Better results were achieved with the transmitter design in Scottish-American Alexander Graham Bells telephone of 1876 – the diaphragm was attached to a conductive rod in an acid solution. These systems, however, gave a poor sound quality. The first microphone that enabled proper voice telephony was the carbon microphone and this was independently developed by David Edward Hughes in England and Emile Berliner and Thomas Edison in the US. Although Edison was awarded the first patent in mid-1877, Hughes had demonstrated his working device in front of many witnesses some years earlier, the carbon microphone is the direct prototype of todays microphones and was critical in the development of telephony, broadcasting and the recording industries. Thomas Edison refined the carbon microphone into his carbon-button transmitter of 1886 and this microphone was employed at the first ever radio broadcast, a performance at the New York Metropolitan Opera House in 1910. In 1916, E. C. Wente of Western Electric developed the next breakthrough with the first condenser microphone, in 1923, the first practical moving coil microphone was built. The Marconi Skykes or magnetophon, developed by Captain H. J. Round, was the standard for BBC studios in London and this was improved in 1930 by Alan Blumlein and Herbert Holman who released the HB1A and was the best standard of the day. Also in 1923, the microphone was introduced, another electromagnetic type, believed to have been developed by Harry F. Olson. Over the years these microphones were developed by companies, most notably RCA that made large advancements in pattern control. With television and film technology booming there was demand for high fidelity microphones, electro-Voice responded with their Academy Award-winning shotgun microphone in 1963. During the second half of 20th century development advanced quickly with the Shure Brothers bringing out the SM58, digital was pioneered by Milab in 1999 with the DM-1001. The latest research developments include the use of optics, lasers and interferometers
30.
Master of ceremonies
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A master of ceremonies, abbreviated M. C. also called compère and announcer, is the official host of a ceremony, a staged event or similar performance. The master of ceremonies sometimes also refers to the officer during an official state function. Today, the term often connotes a master of ceremonies who presents performers, speaks to the audience, entertains people, in addition, the term also exists in various chivalric orders and fraternal orders. The term originated in the Catholic Church, the Master of Ceremonies is an official of the Papal Court responsible for the proper and smooth conduct of the elegant and elaborate rituals involving the Pope and the sacred liturgy. He may also be an involved in the proper conduct of protocols and ceremonials involving the Roman Pontiff, the Papal Court. Examples of official liturgical books prescribing the rules and regulations of liturgical celebrations are Cæremoniale Romanum, the office of the Master of Ceremonies itself is very old. According to the Catholic Encyclopedia, the most ancient ceremonials and rituals of the Catholic Church are the Ordines Romani, names of Masters of Ceremonies are known since the late Middle Ages and the Renaissance. However, copies of books prescribing the forms of rituals, rites and it is reasonable to assume that the ceremonials themselves pre-date Gelasius. However, documentary evidence from the late Roman period is scarce or lost, the ceremonies and practices of the Byzantine emperors are also known to have influenced the papal court. At a large Catholic church or cathedral, the Master of Ceremonies organizes and rehearses the proceedings and he may also have responsibility for the physical security of the place of worship during the liturgy. At major festivities such as Christmas and Easter, when the liturgies are long and complex, the current papal Master of Ceremonies is Monsignor Guido Marini, who succeeded Archbishop Piero Marini. Masters of Ceremonies at weddings and private events also ensure the coordination of their event, became an alternative title for a rapper and for their role within hip hop music and culture. The term is used as a term of distinction, referring to an artist with good performance skills. An MC focuses on skills, lyrical ability, and subject matter, in any comedy show, the compère is the host of the evenings events, but the precise role and responsibilities will vary depending on the country, venue and style of event. The compère will normally do longer bits at the start of the show and after any interval and they may also be required to make announcements, such as birthdays, anniversaries and bar promotions. In some circles the title Master of Ceremonies is also known as Minister of Ceremonies, in the 1940 Disney film, Fantasia, Deems Taylor is the films Master of Ceremonies. Media related to Master of ceremonies at Wikimedia Commons
31.
Kill switch
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Kill switches are usually designed so as to be obvious even to an untrained operator or a bystander. Many kill switches feature a barrier or other protection against accidental activation. Such a removable barrier is called a Mollyguard. A similar system, usually called a dead mans switch, as its name suggests, is a device intended to stop a machine if the operator becomes incapacitated. They are commonly used in applications and consumer applications. The switch in these cases is held by the user, some riding lawnmowers have a kill switch in the seat which stops the engine and blade if the operators weight is no longer on the seat. On railways, a stop is a full application of the brakes in order to bring a train to a stop as quickly as possible. A similar mechanism is the watchdog timer, in large ships, an emergency stop button pulls the countershaft for the fuel pumps to the stop position, cutting off the fuel supply and stopping the engines. With a controllable-pitch propeller, the button may declutch the engine from the propeller. NASCAR requires all their cars to be equipped with a steering wheel-mounted kill switch, in case the accelerator pedal sticks. Kill switches are used on land vehicles as an anti-theft system. Such devices are placed in bait cars and configured so that observing police can trigger the switch remotely. A related concept is the dead mans switch, where the operator must be holding a button or lever any time the vehicle is operating. This prevents it from becoming a vessel that could impose a danger to other vessels or swimmers at sea. A similar device is featured on most lawnmowers, a lever on the blocks the engines fuel supply. Monster Truck Racing Association requires all of their trucks to be equipped with kill switches, in case the monster truck loses control. Monster trucks kill switches are tested before races, on large industrial machines, an emergency stop button is typically located on the panel, and possibly in several other areas of the machine. This provides a means to disconnect the energy source of the device to protect workers
32.
Dance
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Dance is a performance art form consisting of purposefully selected sequences of human movement. This movement has aesthetic and symbolic value, and is acknowledged as dance by performers and observers within a particular culture, Dance can be categorized and described by its choreography, by its repertoire of movements, or by its historical period or place of origin. Other forms of movement are sometimes said to have a dance-like quality, including martial arts, gymnastics, figure skating, synchronized swimming. Theatrical dance, also called performance or concert dance, is intended primarily as a spectacle and it often tells a story, perhaps using mime, costume and scenery, or else it may simply interpret the musical accompaniment, which is often specially composed. Examples are western ballet and modern dance, Classical Indian dance and Chinese and Japanese song, most classical forms are centred upon dance alone, but performance dance may also appear in opera and other forms of musical theatre. Such dance seldom has any narrative, a group dance and a corps de ballet, a social partner dance and a pas de deux, differ profoundly. Even a solo dance may be solely for the satisfaction of the dancer. On the other hand, some cultures lay down strict rules as to the dances in which, for example. Archeological evidence for early dance includes 9, 000-year-old paintings in India at the Rock Shelters of Bhimbetka and it has been proposed that before the invention of written languages, dance was an important part of the oral and performance methods of passing stories down from generation to generation. The use of dance in trance states and healing rituals is thought to have been another early factor in the social development of dance. References to dance can be found in very early recorded history, Greek dance is referred to by Plato, Aristotle, Plutarch, the Bible and Talmud refer to many events related to dance, and contain over 30 different dance terms. In Chinese pottery as early as the Neolithic period, groups of people are depicted dancing in a line holding hands, Dance is further described in the Lüshi Chunqiu. Primitive dance in ancient China was associated with sorcery and shamanic rituals, during the first millennium BCE in India, many texts were composed which attempted to codify aspects of daily life. Bharata Munis Natyashastra is one of the earlier texts and it mainly deals with drama, in which dance plays an important part in Indian culture. It categorizes dance into four types - secular, ritual, abstract, the text elaborates various hand-gestures and classifies movements of the various limbs, steps and so on. A strong continuous tradition of dance has since continued in India, through to modern times, where it continues to play a role in culture, ritual, and, notably, the Bollywood entertainment industry. Many other contemporary dance forms can likewise be traced back to historical, traditional, ceremonial, Dance is generally, though not exclusively, performed with the accompaniment of music and may or may not be performed in time to such music. Some dance may provide its own audible accompaniment in place of music, many early forms of music and dance were created for each other and are frequently performed together
33.
Rave
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A rave is a large dance party featuring performances by DJs and occasionally live performers playing electronic music. The music is amplified with a large, powerful sound reinforcement system, the music is accompanied by laser light shows, projected images, visual effects and fog machines. The word rave was first used in the late 1980s to describe the subculture grew out of the acid house movement. While some raves may be small parties held at nightclubs or private residences, some raves have grown to immense size, some electronic dance music festivals have features of raves, but on a large, often commercial scale. Raves may last for a time, with some events continuing for twenty-four hours. In the late 1950s in London the term rave was used to describe the wild bohemian parties of the Soho beatnik set, in 1958, Buddy Holly recorded the hit Rave On, citing the madness and frenzy of a feeling and the desire for it never to end. The word rave was used in the burgeoning mod youth culture of the early 1960s as the way to describe any wild party in general. People who were gregarious party animals were described as ravers, pop musicians such as Steve Marriott of The Small Faces and Keith Moon of The Who were self-described ravers. Presaging the words subsequent 1980s association with music, the word rave was a common term used regarding the music of mid-1960s garage rock. It was later part of the title of a music performance event held on 28 January 1967 at Londons Roundhouse titled the Million Volt Light. The event featured the only public airing of an experimental sound collage created for the occasion by Paul McCartney of The Beatles – the legendary Carnival of Light recording. With the rapid change of British pop culture from the mod era of 1963–1966 to the era of 1967 and beyond. Its use during that era would have perceived as a quaint or ironic use of bygone slang. Also during the 1970s the Chicago house movement continued to expand along with a new club - Studio 54, Studio 54 was a world-famous New York nightclub and discothèque. Founded and created by Steve Rubell and Ian Schrager in 1977, Rubell and Schrager hired Scott Bromley as architect, Ron Doud as interior designer and Brian Thompson as lighting designer. Where formerly all clubs had very dark, at Studio 54 the crowd could be lit brightly. In the late 1970s, the club was arguably the best-known nightclub in the world, the perception of the word changed again in the late 1980s when the term was revived and adopted by a new youth culture, possibly inspired by the use of the term in Jamaica. In the late 1980s, the word rave was adopted to describe the subculture grew out of the acid house movement
34.
Audio power amplifier
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This includes both amplifiers used in home audio systems and musical instrument amplifiers like guitar amplifiers. It is the electronic stage in a typical audio playback chain before the signal is sent to the loudspeakers. The inputs can also be any number of sources like record players, CD players, digital audio players. Most audio power amplifiers require these low-level inputs, which are line level, the audio amplifier was invented in 1909 by Lee De Forest when he invented the triode vacuum tube. The triode was a three terminal device with a grid that can modulate the flow of electrons from the filament to the plate. The triode vacuum amplifier was used to make the first AM radio, early audio power amplifiers were based on vacuum tubes and some of these achieved notably high audio quality. Audio power amplifiers based on transistors became practical with the availability of inexpensive transistors in the late 1960s. Since the 1970s, most modern audio amplifiers are based on solid state devices, transistor-based amplifiers are lighter in weight, more reliable and require less maintenance than tube amplifiers. In the 2010s, there are still audio enthusiasts, musicians, audio engineers and music producers who prefer tube-based amplifiers, key design parameters for audio power amplifiers are frequency response, gain, noise, and distortion. These are interdependent, increasing gain often leads to increases in noise. While negative feedback reduces the gain, it also reduces distortion. Most audio amplifiers are linear amplifiers operating in class AB, until the 1970s, most amplifiers were tube amplifiers which used vacuum tubes. During the 1970s, tube amps were increasingly replaced with transistor-based amplifiers, which were lighter in weight, more reliable, one alternative to a separate preamp is to simply use passive volume and switching controls, sometimes integrated into a power amplifier to form an integrated amplifier. The final stage of amplification, after preamplifiers, is the output stage, for this reason, the design choices made around the output device or devices, such as the Class of operation of the output devices is often taken as the description of the whole power amplifier. For example, a Class B amplifier will probably have just the power output devices operating cut off for half of each cycle, while the other devices operate in Class A. In a transformerless output stage, the devices are essentially in series with the supply and output load. For some years following the introduction of solid state amplifiers, their perceived sound did not have the excellent audio quality of the best valve amplifiers and this led audiophiles to believe that tube sound or valve sound had an intrinsic quality due to the vacuum tube technology itself. In 1970, Matti Otala published a paper on the origin of a previously unobserved form of distortion, transient intermodulation distortion, TIM distortion was found to occur during very rapid increases in amplifier output voltage
35.
Loudspeaker enclosure
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As such, a loudspeaker cannot be used without installing it in a cabinet of some type, or mounting it into a wall or ceiling. The enclosure also plays a role in managing vibration induced by the frame and moving airmass within the enclosure, as well as heat generated by driver voice coils. Sometimes considered part of the enclosure, the base, may include specially designed feet to decouple the speaker from the floor, enclosures designed for use in PA systems, sound reinforcement systems and for use by electric musical instrument players. Speaker enclosures are used in homes in stereo systems, home cinema systems, televisions, boom boxes, small speaker enclosures are used in car stereo systems. Speaker cabinets are key components of a number of applications, including sound reinforcement systems, movie theatre sound systems. Electric musical instruments invented in the 20th century, such as the guitar, electric bass and synthesizer, among others, are amplified using instrument amplifiers. Early on, radio loudspeakers consisted of horns, often separately from the radio itself. When paper cone loudspeaker drivers were introduced in the mid 1920s and these cabinets were made largely for the sake of appearance, with the loudspeaker simply mounted behind a round hole in the cabinet. It was observed that the enclosure had an effect on the bass response of the speaker. This results in a loss of bass and comb filtering, before the 1950s many manufacturers did not fully enclose their loudspeaker cabinets, the back of the cabinet was typically left open. This was done for reasons, not least because electronics could be placed inside. In some respects, the mounting for a low-frequency loudspeaker driver would be a rigid flat panel of infinite size with infinite space behind it. This would entirely prevent the sound waves from interfering with the sound waves from the front. An open baffle loudspeaker is an approximation of this, since the driver is mounted on a panel, a speaker driver mounted on a finite baffle will display a physical phenomenon known as interference which can result in a perceivable frequency-dependent sound attenuation. This phenomenon is particularly noticeable at low frequencies where the wavelengths are large enough that interference will affect the entire listening area, the box is typically made of wood, wood composite, or more recently plastic, for reasons of ease of construction and appearance. Stone, concrete, plaster, and even building structures have also been used, wharfedale, in some designs, reduced panel resonance by using two wooden cabinets with the space between filled with sand. Home experimenters have even designed speakers built from concrete, granite, many diffraction problems, above the lower frequencies, can be alleviated by the shape of the enclosure, such as by avoiding sharp corners on the front of the enclosure. Research experiments from the 1930s by Dr. Harry F. Olson showed that curved loudspeaker baffles reduce some response deviations due to sound wave diffraction and it was discovered later that careful placement of a speaker on a sharp-edged baffle can reduce diffraction-caused response problems
36.
Subwoofer
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A subwoofer is a woofer, or a complete loudspeaker, which is dedicated to the reproduction of low-pitched audio frequencies known as bass. The typical frequency range for a subwoofer is about 20–200 Hz for consumer products, below 100 Hz for professional live sound, subwoofers are intended to augment the low frequency range of loudspeakers covering higher frequency bands. While the term subwoofer technically only refers to the driver, in common parlance. Subwoofers are made up of one or more woofers mounted in a loudspeaker enclosure—often made of wood—capable of withstanding air pressure while resisting deformation, passive subwoofers have a subwoofer driver and enclosure and they are powered by an external amplifier. Active subwoofers include a built-in amplifier, the first subwoofers were developed in the 1960s to add bass response to home stereo systems. Subwoofers came into popular consciousness in the 1970s with the introduction of Sensurround in movies such as Earthquake. During the 1990s, subwoofers also became popular in home stereo systems, custom car audio installations. By the 2000s, subwoofers became almost universal in sound reinforcement systems in nightclubs, Dones loudspeaker was marketed in the US under the trade name The Octavium from the early 1960s to the mid-1970s. The Octavium was utilized by recording artists of that era, most notably the Grateful Dead, bassist Monk Montgomery, bassist Nathan East. The Octavium speaker and Dones subwoofer technology was utilized, in a few select theaters. During the late 1960s Dones’ Octavium was favorably reviewed by publications including Hi-Fi News. Another early subwoofer enclosure made for home and studio use was the bass speaker for the Servo Statik 1 by New Technology Enterprises. In 1968, the two found outside investors and reorganized as Infinity, the subwoofer was reviewed positively in Stereophile magazines Winter 1968 issue as the SS-1 by Infinity. The SS-1 was reviewed very highly in 1970 by High Fidelity magazine, another of the early subwoofers was developed during the late 1960s by Ken Kreisel, the former president of the Miller & Kreisel Sound Corporation in Los Angeles. Infinitys full range electrostatic speaker system that was developed during the 1960s also used a woofer to cover the frequency range that its electrostatic arrays did not handle adequately. Subwoofers received a deal of publicity in 1974 with the movie Earthquake which was released in Sensurround. Four of the subwoofers were positioned in front of the audience under the film screen, powerful noise energy and loud rumbling in the range of 17 Hz to 120 Hz was generated at the level of 110–120 decibels of sound pressure level, abbreviated dB. The new low frequency entertainment method helped the film become a box office success, more Sensurround systems were assembled and installed
37.
Radio station
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A radio station is a set of equipment necessary to carry on communication via radio waves. Generally, it is a receiver or transmitter, an antenna, Radio stations play a vital role in communication technology as they are heavily relied on to transfer data and information across the world. More broadly, the definition of a radio station includes the aforementioned equipment, such a station may include several radio stations defined above. This definition of a station is more often referred to as a transmitter site. Each station shall be classified by the service in which it operates permanently or temporarily», transmitter - Takes the electrical output of a microphone and then modulates a higher-frequency carrier signal and transmits it as radio waves. Receiver - The broadcast message is received by the receiver and decodes the radio sine waves, antenna - An antenna is required for transmission, it is also required to receive radio waves. The main use of an antenna is to radio signals. Aerial feeder - system of feeding HF-Energy in the antenna Transmission lines - Transmission lines are used to transfer the radio signals from one location to another. For example, a line was used in Luftwaffe, Germany during WW II to send information from camps back to their base. Connectors Interface panel remote control – This is used to various different types of the equipment used in a radio station. To input broadcast data into a transmitter an interface panel will need to be used, cable – A cable can be used to connect the various devices. Equipment Rack – To hold all equipment in a secure and logical manner, power protection equipment – For holding equipments in a stable, secure and logical manner. UPS – For uninterrupted power supply and these are the most used/important devices and items for most radio stations. A microphone is used to capture the input of sound created by people speaking into the device. The sounds are turned into electrical energy, this energy then flows along a metal antenna. As the electrons in the current move back and forth up the antenna. The waves travel at the speed of light, taking the program with them. A compound of both a transmitter and a receiver is called a transceiver, they are combined and share common circuitry or a single housing, when no circuitry is common between the transmit and receive functions, the device becomes a transmitter-receiver
38.
Television station
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A television station is a business, organisation or other enterprise, such as an amateur television operator, that transmits content over terrestrial television. A television transmission can occur via analog television signals or, more recently, broadcast television systems standards are set by the government, and these vary around the world. Television stations broadcasting over a system were typically limited to one television channel. The term television station is normally applied to television stations. Television stations usually require a broadcast license from a government agency which sets the requirements, most commercial television stations are owned independently, but many are either affiliated with a television network or are owned-and-operated by a television network. Another form a television station may take is non-commercial educational and considered public broadcasting, some countries have set up nationwide television networks, in which individual television stations act as mere repeaters of nationwide programs. To get a signal from the control room to the transmitter. The link can be either by radio or T1/E1, a transmitter/studio link may also send telemetry back to the station, but this may be embedded in subcarriers of the main broadcast. Stations which retransmit or simulcast another may simply pick-up that station over-the-air, the license usually specifies which other station is it allowed to carry. In North America, full-power stations on band I are generally limited to 100 kW analog video and 10 kW analog audio, stations on band III can go up by 5dB to 316 kW video,31.6 kW audio, or 160 kW digital. Low-VHF stations are subject to long-distance reception just as with FM. There are no stations on Channel 1, UHF, by comparison, has a much shorter wavelength, and thus requires a shorter antenna, but also higher power. North American stations can go up to 5000 kW ERP for video and 500 kW audio, or 1000 kW digital. Low channels travel further than high ones at the same power, despite this, in the U. S. the Federal Communications Commission is taking another large portion of this band away, in contrast to the rest of the world, which has been taking VHF instead. This means that some stations left on VHF are harder to receive after the analog shutdown, since at least 1974, there are no stations on channel 37 in North America for radio astronomy purposes. Most television stations are commercial broadcasting enterprises which are structured in a variety of ways to generate revenue from television commercials and they may be an independent station or part of a broadcasting network, or some other structure. They can produce some or all of their programs or buy some broadcast syndication programming for or all of it from other stations or independent production companies, many stations have some sort of television studio, which on major-network stations is often used for newscasts or other local programming. There is usually a department, where journalists gather information
39.
Audio console
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In the 2010s, a mixer is able to control analog or digital signals, depending on the type of mixer. The modified signals are summed to produce the output signals. A typical, simple application combines signals from two microphones into an amplifier that drives one set of speakers simultaneously, a DJ mixer may have only two channels, for mixing two record players. A coffeehouses tiny stage might only have a six channel mixer, a nightclub stages mixer for rock music shows may have 24 channels for mixing the signals from a rhythm section, lead guitar and several vocalists. A mixing console for a large concert may have 48 channels, a mixing console in a professional recording studio may have as many as 96 channels. In practice, mixers do more than simply mix signals, some mixers have onboard electronic effects, such as reverb. Some mixers intended for small venue live performance applications may include a power amplifier. A mixing console is also known as a mixer, audio console, mixing desk, sound mixer, sound board. A typical analog mixing board has three sections, Channel inputs Master controls Audio level metering The channel input strips are usually a bank of identical monaural or stereo input channels. Each channel has rotary knobs, buttons and/or faders for controlling the gain, the master control section is used to adjust the levels of the overall output of the mixer. The master control section has sub-group faders, master faders, master auxiliary mixing bus level controls, in addition it may have solo monitoring controls, a stage talk-back microphone control, muting controls and an output matrix mixer. On smaller mixers the inputs are on the left of the mixing board, in larger mixers, the master controls are in the center with input faders and channel strips on both sides. The audio level meters may be above the input and master sections or they may be integrated into the input, the audio level meters indicate when the signals are clipping. Each signal that is plugged into the mixer has its own channel, depending on the specific mixer, each channel is stereo or monaural. On most mixers, each channel has an XLR input, the smallest, least expensive mixers may only have one XLR input with the other inputs being line inputs. These can be used by a singer-guitarist or other small acts, below each input, there are usually several rotary controls. The first knob is typically a trim or gain control, the inputs buffer the signal from the external device and this controls the amount of amplification or attenuation needed to bring the signal to a nominal level for processing. This stage is where most noise of interference is picked up, balanced inputs and connectors, such as XLR or phone connectors, reduce interference problems
40.
Tape recorder
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In its present-day form, it records a fluctuating signal by moving the tape across a tape head that polarizes the magnetic domains in the tape in proportion to the audio signal. Tape-recording devices include reel-to-reel tape deck and the cassette deck, the use of magnetic tape for sound recording originated around 1930. Magnetizable tape revolutionized both the radio broadcast and music recording industries and it gave artists and producers the power to record and re-record audio with minimal loss in quality as well as edit and rearrange recordings with ease. The alternative recording technologies of the era, transcription discs and wire recorders, since some early refinements improved the fidelity of the reproduced sound, magnetic tape has been the highest quality analog sound recording medium available. As of the first decade of the 21st century, analog magnetic tape has been replaced by digital recording technologies for consumer purposes. Some individuals and organizations developed innovative uses for magnetic wire recorders while others investigated variations of the technology, one particularly important variation was the application of an oxide powder to a long strip of paper. This German invention was the start of a string of innovations that have led to present day magnetic tape recordings. The earliest known audio tape recorder was a non-magnetic, non-electric version invented by Alexander Graham Bells Volta Laboratory and patented in 1886. It employed a 3⁄16-inch-wide strip of wax-covered paper that was coated by dipping it in a solution of beeswax and paraffin and then had one side scraped clean, the machine was of sturdy wood and metal construction, and hand-powered by means of a knob fastened to the flywheel. The tape was taken up on the other reel. The sharp recording stylus, actuated by a vibrating mica diaphragm, in playback mode, a dull, loosely mounted stylus, attached to a rubber diaphragm, carried the reproduced sounds through an ear tube to its listener. Both recording and playback heads, mounted alternately on the two posts, could be adjusted vertically so that several recordings could be cut on the same 3⁄16-inch-wide strip. While the machine was never developed commercially, it was an ancestor to the modern magnetic tape recorder which it resembled somewhat in design. The tapes and machine created by Bells associates, examined at one of the Smithsonian Institutions museums, became brittle, the machines playback head was also missing. Otherwise, with some reconditioning, they could be placed into working condition, during the recording process, the tape moved through a pair of electrodes which immediately imprinted the modulated sound signals as visible black stripes into the paper tapes surface. On 13 August 1931, Duston filed USPTO Patent Application #556,743 for Method Of And Apparatus For Electrically Recording And Reproducing Sound And Other Vibrations, and which was renewed in 1934. Magnetic recording was conceived as early as 1877 by the American engineer Oberlin Smith, Analog magnetic wire recording, and its successor, magnetic tape recording, involve the use of a magnetizable medium which moves with a constant speed past a recording head. An electrical signal, which is analogous to the sound that is to be recorded, is fed to the recording head, inducing a pattern of magnetization similar to the signal
41.
Hard disk drive
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The platters are paired with magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a manner, meaning that individual blocks of data can be stored or retrieved in any order. HDDs are a type of storage, retaining stored data even when powered off. Introduced by IBM in 1956, HDDs became the dominant secondary storage device for computers by the early 1960s. Continuously improved, HDDs have maintained this position into the era of servers. More than 200 companies have produced HDDs historically, though after extensive industry consolidation most current units are manufactured by Seagate, Toshiba, as of 2016, HDD production is growing, although unit shipments and sales revenues are declining. While SSDs have higher cost per bit, SSDs are replacing HDDs where speed, power consumption, small size, the primary characteristics of an HDD are its capacity and performance. Capacity is specified in unit prefixes corresponding to powers of 1000, the two most common form factors for modern HDDs are 3. 5-inch, for desktop computers, and 2. 5-inch, primarily for laptops. HDDs are connected to systems by standard interface cables such as PATA, SATA, Hard disk drives were introduced in 1956, as data storage for an IBM real-time transaction processing computer and were developed for use with general-purpose mainframe and minicomputers. The first IBM drive, the 350 RAMAC in 1956, was approximately the size of two medium-sized refrigerators and stored five million six-bit characters on a stack of 50 disks. In 1962 the IBM350 RAMAC disk storage unit was superseded by the IBM1301 disk storage unit, cylinder-mode read/write operations were supported, and the heads flew about 250 micro-inches above the platter surface. Motion of the head array depended upon a binary system of hydraulic actuators which assured repeatable positioning. The 1301 cabinet was about the size of three home refrigerators placed side by side, storing the equivalent of about 21 million eight-bit bytes, access time was about a quarter of a second. Also in 1962, IBM introduced the model 1311 disk drive, users could buy additional packs and interchange them as needed, much like reels of magnetic tape. Later models of removable pack drives, from IBM and others, became the norm in most computer installations, non-removable HDDs were called fixed disk drives. Some high-performance HDDs were manufactured with one head per track so that no time was lost physically moving the heads to a track, known as fixed-head or head-per-track disk drives they were very expensive and are no longer in production. In 1973, IBM introduced a new type of HDD code-named Winchester and its primary distinguishing feature was that the disk heads were not withdrawn completely from the stack of disk platters when the drive was powered down. Instead, the heads were allowed to land on an area of the disk surface upon spin-down
42.
Music video
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A music video is a short film integrating a song and imagery, produced for promotional or artistic purposes. Modern music videos are made and used as a marketing device intended to promote the sale of music recordings. There are also cases where songs are used in tie in marketing campaigns that allow them to more than just a song. Tie ins and merchandising could be used in toys or marketing campaigns for food, although the origins of music videos date back to musical short films that first appeared in the 1920s, they came into prominence in the 1980s when MTV based their format around the medium. Prior to the 1980s, these works were described by terms including illustrated song, filmed insert, promotional film, promotional clip, promotional video, song video. Music videos use a range of styles of contemporary videomaking techniques, including animation, live action filming, documentaries. Some music videos blend different styles, such as animation, music, combining these styles and techniques has become more popular because of the variation it presents to the audience. Many music videos interpret images and scenes from the songs lyrics, other music videos may be without a set concept, being merely a filmed version of the songs live performance. Product placement is a technique in music videos, exemplified by the appearance of the Beats Pill in numerous hip hop videos. In 1894, sheet music publishers Edward B, marks and Joe Stern hired electrician George Thomas and various performers to promote sales of their song The Little Lost Child. Using a magic lantern, Thomas projected a series of images on a screen simultaneous to live performances. This would become a form of entertainment known as the illustrated song. In 1926, with the arrival of many musical short films were produced. Vitaphone shorts featured many bands, vocalists and dancers, early 1930s cartoons featured popular musicians performing their hit songs on-camera in live-action segments during the cartoons. The early animated films by Walt Disney, such as the Silly Symphonies shorts and especially Fantasia, the Warner Brothers cartoons, even today billed as Looney Tunes and Merrie Melodies, were initially fashioned around specific songs from upcoming Warner Brothers musical films. Live action musical shorts, featuring such performers as Cab Calloway, were also distributed to theaters. Blues singer Bessie Smith appeared in a short film called St. Louis Blues featuring a dramatized performance of the hit song. Numerous other musicians appeared in short musical subjects during this period, soundies, produced and released from 1940 to 1947, were musical films that often included short dance sequences, similar to later music videos
43.
Foldback (sound engineering)
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Monitor speakers often include a single full-range loudspeaker and a horn in a cabinet. The sound at popular music and rock concerts is amplified with power amplifiers through a PA system or sound reinforcement system. With the exception of the smallest venues, such as coffeehouses, the main or front of house system is a PA system/sound reinforcement system which amplifies the onstage sounds for the main audience. The monitor system consists of monitor speakers aimed at the performers rather than the audience. Monitor systems have a range of sizes and complexity. In most mid- to large-size venues, there is a sound engineer. The monitor mix is different from the front of house mix. In the most sophisticated and expensive monitor set-ups, each onstage performer can ask the engineer for a separate monitor mix for separate monitors. For example, the singer can ask to hear mostly her/his voice in the monitor in front of her/him. Without a foldback system, the sound that on-stage performers would hear from front of house would be the reverberated reflections bouncing from the wall of the venue. The naturally reflected sound is delayed and distorted, which could, for example, in situations with poor or absent foldback mixes, vocalists may end up singing off-tune or out of time with the band. Each system consists of a board, sound processing equipment, power amplifiers. The two systems usually share microphones and direct inputs using a splitter microphone snake, there is disagreement over when to call these audio systems Sound Reinforcement systems or Public Address systems. This distinction is important in regions or markets, while in other regions or markets the terms are interchangeable. A large club may use several power amplifiers to provide 1000 to 2000 watts of power to the main speakers, an outdoor rock concert may use large racks of a number of power amplifiers to provide 10,000 or more watts. The monitor system reproduces the sounds of the performance and directs them towards the performers, to help them hear the instruments. The monitor system in a coffeehouse or singer-songwriter stage for a bar may be a single 100 watt powered monitor wedge. In the smallest PA systems, the performer may set their own main, the simplest monitor systems consist of a single monitor speaker for the lead vocalist which amplifies their singing voice, so that they can hear it clearly
44.
Boom box
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Boombox is a common term for a portable transistorized cassette tape recorder/player and AM/FM radio with an amplifier, two or more loudspeakers and a carrying handle. A boombox is a device capable of receiving radio stations. Many models are capable of recording onto cassette tapes from radio. Designed for portability, boomboxes can be powered by batteries as well as by line current, the boombox was introduced to the American market during the mid-1970s. The desire for louder and heavier bass led to bigger and heavier boxes, by the 1980s, most boomboxes were battery-operated, leading to extremely heavy, bulky boxes. The boombox quickly became associated with society in the United States, particularly African American. Cities petitioned for the banning of boomboxes from public places, the boombox became closely linked to American hip hop culture and was instrumental in the rise of hip hop music. The first boombox was developed by the inventor of the compact cassette. Their first Radiorecorder was released in 1966, the Philips innovation was the first time that radio broadcasts could be recorded onto cassette tapes without the cables or microphones that previous stand-alone cassette tape recorders required. Although sound quality of tape recordings was poor, improvements in technology and the introduction of stereo recording, chromium tapes. Several European electronics brands, such as Grundig, also introduced similar devices, boomboxes were soon also developed in Japan in the early 1970s and became popular there due to their compact size and impressive sound quality. The Japanese brands soon took over a portion of the European boombox market and were often the first Japanese consumer electronics brands that a European household might purchase. The Japanese innovated by creating different sizes, form factors, and technology, introducing such advances as stereo boomboxes, removable speakers, in-built TV receivers, and inbuilt CD players. The boombox was introduced to the American market during the mid-1970s, with the bulk of production being carried out by Panasonic, Sony, Marantz, and General Electric. It was immediately noticed by the urban adolescent community and soon had a market, especially in metropolitan centers such as New York, Los Angeles. The development of audio jacks brought the boombox to the height of its popularity, consumers enjoyed the portability and sound quality of boomboxes, but one of the most important features, especially to the youth market, was the bass. The desire for louder and heavier bass led to bigger and heavier boxes, most units can be powered by AC or DC cables in addition to batteries. As boomboxes grew in popularity, they became more complex in design
45.
Grand Wizzard Theodore
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Theodore Livingston, better known as Grand Wizzard Theodore, is an American hip hop DJ. He is widely credited as the inventor of the scratching technique, in addition to scratching, he achieved renown for his mastery of needle drops and other techniques which he invented or perfected. Born in Bronx, New York, Theodores brother, Mean Gene, was his mentor, Theodore also apprenticed under Grandmaster Flash. Though variants of the story exist, it is accepted that Grand Wizard Theodore was playing records at a high volume in his bedroom. Fed up with the noise his mother entered and ordered him to turn the music down, at this point he looked away from the turntable to face her. While his mother lectured him he continued slowly moving the back and forth. When she left the room he was intrigued by the sound the vinyl made when manipulated in this fashion, after months of experimentation he introduced this technique at a party and thus scratching was born. Many forms of music have since used the technique. In the early 1980s, Theodore was a part of the group Grandwizard Theodore & the Fantastic Five and they released Can I Get a Soul Clap in 1982. He was also featured in the 1983 film Wild Style, as well as contributing to the films soundtrack and he explains the origin of the scratch in the documentary, Scratch. Theodores phrase Say turn it up from his track Fantastic Freaks at the Dixie was sampled by hip hop and rap acts such as Public Enemy, Bomb the Bass, hiphop. sh/theo Grand Wizard Theodore on Peter Rosenbergs Juan Epstein podcast. Archived from the original on December 15,2014, DJ Grand Wizzard Theodore Interview - NAMM Oral History Library
