Misplaced Pages

#788211

105-465: Discs were the only means of preserving sound before the introduction of magnetic tapes. Until the advent of the vinyl in the 1950s, the records were made of shellac or wax. The organic composition of these materials enabled them to degrade over time and also made them prone to attack by fungi. As a result, many records, including unique original radio productions, are in a state of deterioration which precludes play by traditional mechanical means, hence

210-448: A Times music critic stated: ... the time has come for serious musical criticism to take account of performances of great music reproduced by means of the records. To claim that the records have succeeded in exact and complete reproduction of all details of symphonic or operatic performances ... would be extravagant ... [but] the article of today is so far in advance of the old machines as hardly to admit classification under

315-401: A de luxe price. Later, Decca Records introduced vinyl Deccalite 78s, while other record companies used various vinyl formulations trademarked as Metrolite, Merco Plastic, and Sav-o-flex, but these were mainly used to produce "unbreakable" children's records and special thin vinyl DJ pressings for shipment to radio stations. The playing time of a phonograph record is directly proportional to

420-513: A 10-inch 78 in 1922 for Victor . Longer musical pieces were released as a set of records. In 1903 His Master's Voice in England made the first complete recording of an opera, Verdi 's Ernani , on 40 single-sided discs. In 1940, Commodore released Eddie Condon and his Band's recording of " A Good Man Is Hard to Find " in four parts, issued on both sides of two 12-inch 78s. The limited duration of recordings persisted from their advent until

525-442: A 12-inch conductive vinyl disc. Decibel The decibel (symbol: dB ) is a relative unit of measurement equal to one tenth of a bel ( B ). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale . Two signals whose levels differ by one decibel have a power ratio of 10 (approximately 1.26 ) or root-power ratio of 10 (approximately 1.12 ). The unit fundamentally expresses

630-446: A 3.5 dB/km fiber yields a loss of 0.35 dB = 3.5 dB/km × 0.1 km. The human perception of the intensity of sound and light more nearly approximates the logarithm of intensity rather than a linear relationship (see Weber–Fechner law ), making the dB scale a useful measure. The decibel is commonly used in acoustics as a unit of sound power level or sound pressure level . The reference pressure for sound in air

735-608: A basic, inexpensive turntable called the Duo Jr., which was designed to be connected to their radio receivers. According to Edward Wallerstein (the general manager of the RCA Victor Division), this device was "instrumental in revitalizing the industry". The production of shellac records continued throughout the 78 rpm era, which lasted until 1948 in industrialized nations. During the Second World War,

840-407: A bel would normally be written 0.05 dB, and not 5 mB. The method of expressing a ratio as a level in decibels depends on whether the measured property is a power quantity or a root-power quantity ; see Power, root-power, and field quantities for details. When referring to measurements of power quantities, a ratio can be expressed as a level in decibels by evaluating ten times

945-415: A broader and smoother frequency response, which produced a dramatically fuller, clearer and more natural-sounding recording. Soft or distant sounds that were previously impossible to record could now be captured. Volume was now limited only by the groove spacing on the record and the amplification of the playback device. Victor and Columbia licensed the new electrical system from Western Electric and recorded

1050-558: A competing vinyl format, the 7-inch (175 mm) 45 rpm disc, with a much larger center hole. For a two-year period from 1948 to 1950, record companies and consumers faced uncertainty over which of these formats would ultimately prevail in what was known as the "War of the Speeds" (see also Format war ). In 1949 Capitol and Decca adopted the new LP format and RCA Victor gave in and issued its first LP in January 1950. The 45 rpm size

1155-502: A decibel is one-tenth of a bel). P and P 0 must measure the same type of quantity, and have the same units before calculating the ratio. If P = P 0 in the above equation, then L P = 0. If P is greater than P 0 then L P is positive; if P is less than P 0 then L P is negative. Rearranging the above equation gives the following formula for P in terms of P 0 and L P  : When referring to measurements of root-power quantities, it

SECTION 10

#1732783102789

1260-698: A favorable response to a new unit definition among members of the International Advisory Committee on Long Distance Telephony in Europe and replaced the MSC with the Transmission Unit (TU). 1 TU was defined such that the number of TUs was ten times the base-10 logarithm of the ratio of measured power to a reference power. The definition was conveniently chosen such that 1 TU approximated 1 MSC; specifically, 1 MSC

1365-437: A frequency of 5000   radians per second (795.8 Hz), and matched closely the smallest attenuation detectable to a listener. A standard telephone cable was "a cable having uniformly distributed resistance of 88 ohms per loop-mile and uniformly distributed shunt capacitance of 0.054  microfarads per mile" (approximately corresponding to 19  gauge wire). In 1924, Bell Telephone Laboratories received

1470-421: A governor and says that spring drives had replaced hand drives. It notes that: The speed regulator was furnished with an indicator that showed the speed when the machine was running so that the records, on reproduction, could be revolved at exactly the same speed...The literature does not disclose why 78 rpm was chosen for the phonograph industry, apparently this just happened to be the speed created by one of

1575-453: A linear scale, adding there, and then taking logarithms to return. For example, where operations on decibels are logarithmic addition/subtraction and logarithmic multiplication/division, while operations on the linear scale are the usual operations: The logarithmic mean is obtained from the logarithmic sum by subtracting 10 log 10 ⁡ 2 {\displaystyle 10\log _{10}2} , since logarithmic division

1680-428: A manner similar to scientific notation . This allows one to clearly visualize huge changes of some quantity. See Bode plot and Semi-log plot . For example, 120 dB SPL may be clearer than "a trillion times more intense than the threshold of hearing". Level values in decibels can be added instead of multiplying the underlying power values, which means that the overall gain of a multi-component system, such as

1785-748: A niche resurgence in the early 21st century, growing increasingly popular throughout the 2010s and 2020s. Phonograph records are generally described by their diameter in inches (12-inch, 10-inch, 7-inch), the rotational speed in revolutions per minute (rpm) at which they are played ( 8 + 1 ⁄ 3 , 16 + 2 ⁄ 3 , 33 + 1 ⁄ 3 , 45, 78), and their time capacity, determined by their diameter and speed (LP [long play], 12-inch disc, 33 + 1 ⁄ 3  rpm; EP [extended play], 12-inch disc or 7-inch disc, 33 + 1 ⁄ 3 or 45 rpm; Single, 7-inch or 10-inch disc, 45 or 78 rpm); their reproductive quality, or level of fidelity (high-fidelity, orthophonic, full-range, etc.); and

1890-656: A phonograph record that would hold at least 20 minutes per side. Research began in 1939, was suspended during World War II, and then resumed in 1945. Columbia Records unveiled the LP at a press conference in the Waldorf-Astoria on 21 June 1948, in two formats: 10 inches (25 centimetres) in diameter, matching that of 78 rpm singles, and 12 inches (30 centimetres) in diameter. Unwilling to accept and license Columbia's system, in February 1949, RCA Victor released

1995-434: A power ratio of 10 , or 1.9953 , about 0.24% different from exactly 2, and a voltage ratio of 1.4125 , 0.12% different from exactly √ 2 . Similarly, an increase of 6.000 dB corresponds to the power ratio is 10 ≈ 3.9811 , about 0.5% different from 4. The decibel is useful for representing large ratios and for simplifying representation of multiplicative effects, such as attenuation from multiple sources along

2100-440: A power ratio, it is defined as ten times the logarithm with base 10 . That is, a change in power by a factor of 10 corresponds to a 10 dB change in level. When expressing root-power quantities, a change in amplitude by a factor of 10 corresponds to a 20 dB change in level. The decibel scales differ by a factor of two, so that the related power and root-power levels change by the same value in linear systems, where power

2205-459: A ratio between two root-power quantities of √ 10 :1. Two signals whose levels differ by one decibel have a power ratio of 10 , which is approximately 1.258 93 , and an amplitude (root-power quantity) ratio of 10 ( 1.122 02 ). The bel is rarely used either without a prefix or with SI unit prefixes other than deci ; it is customary, for example, to use hundredths of a decibel rather than millibels . Thus, five one-thousandths of

SECTION 20

#1732783102789

2310-417: A relative change but may also be used to express an absolute value as the ratio of a value to a fixed reference value; when used in this way, the unit symbol is often suffixed with letter codes that indicate the reference value. For example, for the reference value of 1  volt , a common suffix is " V " (e.g., "20 dBV"). Two principal types of scaling of the decibel are in common use. When expressing

2415-499: A rotational speed of 78 rpm , giving it the nickname " 78s " ("seventy-eights"). After the 1940s, "vinyl" records made from polyvinyl chloride (PVC) became standard replacing the old 78s and remain so to this day; they have since been produced in various sizes and speeds, most commonly 7-inch discs played at 45 rpm (typically for singles , also called 45s ("forty-fives")), and 12-inch discs played at 33⅓ rpm (known as an LP , "long-playing records", typically for full-length albums ) –

2520-411: A scanner prototype to do this. The current version of the scanner is made of a glass rotating plate, on which is placed the film. The digitisation of the image is done by a linear CCD camera of 2048 pixels wide, which takes pictures at regular intervals, with frequencies ranging from 25,000 to 200,000 lines per rotation. The combination of the camera with the rotating film delivers a rotary scan of

2625-418: A series of amplifier stages, can be calculated by summing the gains in decibels of the individual components, rather than multiply the amplification factors; that is, log( A × B × C ) = log( A ) + log( B ) + log( C ). Practically, this means that, armed only with the knowledge that 1 dB is a power gain of approximately 26%, 3 dB is approximately 2× power gain, and 10 dB is 10× power gain, it

2730-406: A signal chain. Its application in systems with additive effects is less intuitive, such as in the combined sound pressure level of two machines operating together. Care is also necessary with decibels directly in fractions and with the units of multiplicative operations. The logarithmic scale nature of the decibel means that a very large range of ratios can be represented by a convenient number, in

2835-584: A small solid circle that fit onto the bottom of the spindle (meaning only one 45 could be played at a time) or a larger adapter that fit over the entire spindle, permitting a stack of 45s to be played. RCA Victor 45s were also adapted to the smaller spindle of an LP player with a plastic snap-in insert known as a " 45 rpm adapter ". These inserts were commissioned by RCA president David Sarnoff and were invented by Thomas Hutchison. Capacitance Electronic Discs were videodiscs invented by RCA, based on mechanically tracked ultra-microgrooves (9541 grooves/inch) on

2940-427: A special release for Record Store Day 2011, Capitol re-released The Beach Boys single " Good Vibrations " in the form of a 10-inch 78-rpm record (b/w "Heroes and Villains"). More recently, The Reverend Peyton's Big Damn Band has released their tribute to blues guitarist Charley Patton Peyton on Patton on both 12-inch LP and 10-inch 78s. CBS Laboratories had long been at work for Columbia Records to develop

3045-409: A stylus following the groove. The radial displacement of the groove is observable through a microscope which means that sound information is visible. If a high-resolution analog picture of each side of the record is taken and the information in the film is then digitised using a circular scanner, various algorithms can process the image in order to extract and reconstruct the sound. A central part of

3150-421: A subtraction ( C / N 0 ) dB = C dB − N 0 dB . However, the linear-scale units still simplify in the implied fraction, so that the results would be expressed in dB-Hz. According to Mitschke, "The advantage of using a logarithmic measure is that in a transmission chain, there are many elements concatenated, and each has its own gain or attenuation. To obtain the total, addition of decibel values

3255-455: A three- or four-speed player (78, 45, 33 + 1 ⁄ 3 , and sometimes 16 + 2 ⁄ 3  rpm); with changer, a tall spindle that would hold several records and automatically drop a new record on top of the previous one when it had finished playing, a combination cartridge with both 78 and microgroove styli and a way to flip between the two; and some kind of adapter for playing the 45s with their larger center hole. The adapter could be

VisualAudio - Misplaced Pages Continue

3360-485: A time, with four items per EP, or in a boxed set with three EPs or twelve items. The large center hole on 45s allows easier handling by jukebox mechanisms. EPs were generally discontinued by the late 1950s in the U.S. as three- and four-speed record players replaced the individual 45 players. One indication of the decline of the 45 rpm EP is that the last Columbia Records reissue of Frank Sinatra songs on 45 rpm EP records, called Frank Sinatra (Columbia B-2641)

3465-441: A track from his self-titled debut album (with "The Beehive State" on the flipside). Reprise did not proceed further with the series due to a lack of sales for the single, and a lack of general interest in the concept. In 1978, guitarist and vocalist Leon Redbone released a promotional 78-rpm single featuring two songs ("Alabama Jubilee" and "Please Don't Talk About Me When I'm Gone") from his Champagne Charlie album. In

3570-400: A unit of logarithmic power ratio, while the neper is used for logarithmic root-power (amplitude) ratio. The unit dBW is often used to denote a ratio for which the reference is 1 W, and similarly dBm for a 1 mW reference point. (31.62 V / 1 V) ≈ 1 kW / 1 W , illustrating the consequence from the definitions above that L G has the same value, 30 dB, regardless of whether it

3675-431: A variety known as extended play (EP), which achieved up to 10–15 minutes play at the expense of attenuating (and possibly compressing) the sound to reduce the width required by the groove. EP discs were cheaper to produce and were used in cases where unit sales were likely to be more limited or to reissue LP albums on the smaller format for those people who had only 45 rpm players. LP albums could be purchased one EP at

3780-401: A variety of sizes. As early as 1894, Emile Berliner 's United States Gramophone Company was selling single-sided 7-inch discs with an advertised standard speed of "about 70 rpm". One standard audio recording handbook describes speed regulators, or governors , as being part of a wave of improvement introduced rapidly after 1897. A picture of a hand-cranked 1898 Berliner Gramophone shows

3885-469: Is almost universally rounded to 3 dB in technical writing. This implies an increase in voltage by a factor of √ 2 ≈ 1.4142 . Likewise, a doubling or halving of the voltage, corresponding to a quadrupling or quartering of the power, is commonly described as 6 dB rather than ± 6.0206  dB. Should it be necessary to make the distinction, the number of decibels is written with additional significant figures . 3.000 dB corresponds to

3990-634: Is an interesting jigsaw puzzle. As the cracks are due to the shrinkage of the lacquer, there is no material loss in most of the cases. To solve this problem, in November 2006, the Swiss National Sound Archives started a project funded by the Gebert Rüf Foundation. The results so far are encouraging. The algorithm basically uses signal features to determine whether two groove parts are contiguous or not. The project

4095-402: Is deprecated by that standard and root-power is used throughout this article. Although power and root-power quantities are different quantities, their respective levels are historically measured in the same units, typically decibels. A factor of 2 is introduced to make changes in the respective levels match under restricted conditions such as when the medium is linear and the same waveform

4200-416: Is linear subtraction. Attenuation constants, in topics such as optical fiber communication and radio propagation path loss , are often expressed as a fraction or ratio to distance of transmission. In this case, dB/m represents decibel per meter, dB/mi represents decibel per mile, for example. These quantities are to be manipulated obeying the rules of dimensional analysis , e.g., a 100-meter run with

4305-490: Is much more convenient than multiplication of the individual factors." However, for the same reason that humans excel at additive operation over multiplication, decibels are awkward in inherently additive operations: if two machines each individually produce a sound pressure level of, say, 90 dB at a certain point, then when both are operating together we should expect the combined sound pressure level to increase to 93 dB, but certainly not to 180 dB!; suppose that

VisualAudio - Misplaced Pages Continue

4410-411: Is obtained from powers or from amplitudes, provided that in the specific system being considered power ratios are equal to amplitude ratios squared. A change in power ratio by a factor of 10 corresponds to a change in level of 10 dB . A change in power ratio by a factor of 2 or ⁠ 1 / 2 ⁠ is approximately a change of 3 dB . More precisely, the change is ± 3.0103  dB, but this

4515-795: Is possible to determine the power ratio of a system from the gain in dB with only simple addition and multiplication. For example: However, according to its critics, the decibel creates confusion, obscures reasoning, is more related to the era of slide rules than to modern digital processing, and is cumbersome and difficult to interpret. Quantities in decibels are not necessarily additive , thus being "of unacceptable form for use in dimensional analysis ". Thus, units require special care in decibel operations. Take, for example, carrier-to-noise-density ratio C / N 0 (in hertz), involving carrier power C (in watts) and noise power spectral density N 0 (in W/Hz). Expressed in decibels, this ratio would be

4620-625: Is proportional to the square of amplitude. The definition of the decibel originated in the measurement of transmission loss and power in telephony of the early 20th century in the Bell System in the United States. The bel was named in honor of Alexander Graham Bell , but the bel is seldom used. Instead, the decibel is used for a wide variety of measurements in science and engineering , most prominently for sound power in acoustics , in electronics and control theory . In electronics,

4725-590: Is recognized by other international bodies such as the International Electrotechnical Commission (IEC) and International Organization for Standardization (ISO). The IEC permits the use of the decibel with root-power quantities as well as power and this recommendation is followed by many national standards bodies, such as NIST , which justifies the use of the decibel for voltage ratios. In spite of their widespread use, suffixes (such as in dBA or dBV) are not recognized by

4830-452: Is set at the typical threshold of perception of an average human and there are common comparisons used to illustrate different levels of sound pressure . As sound pressure is a root-power quantity, the appropriate version of the unit definition is used: where p rms is the root mean square of the measured sound pressure and p ref is the standard reference sound pressure of 20 micropascals in air or 1 micropascal in water. Use of

4935-483: Is still in a test validation phase, but some sound is already available. Reaching the same quality as good as an original record replayed on a modern turntable is probably unrealistic. Originally around 20 dB in the early prototype, the signal-to-noise ratio of modern system is situated around 19 dB for a good 78 rpm record. With its intermediate photographic stage, this solution solves several significant challenges found in archiving systems. Disadvantages of

5040-409: Is under consideration with changes in amplitude, or the medium impedance is linear and independent of both frequency and time. This relies on the relationship holding. In a nonlinear system, this relationship does not hold by the definition of linearity. However, even in a linear system in which the power quantity is the product of two linearly related quantities (e.g. voltage and current ), if

5145-440: Is usual to consider the ratio of the squares of F (measured) and F 0 (reference). This is because the definitions were originally formulated to give the same value for relative ratios for both power and root-power quantities. Thus, the following definition is used: The formula may be rearranged to give Similarly, in electrical circuits , dissipated power is typically proportional to the square of voltage or current when

5250-441: Is widely used among the foreign telephone organizations and recently it was termed the "decibel" at the suggestion of the International Advisory Committee on Long Distance Telephony. The decibel may be defined by the statement that two amounts of power differ by 1 decibel when they are in the ratio of 10 and any two amounts of power differ by N decibels when they are in the ratio of 10 . The number of transmission units expressing

5355-662: The Victor Talking Machine Company in Camden, New Jersey, whose products would come to dominate the market for several decades. Berliner's Montreal factory, which became the Canadian branch of RCA Victor , still exists. There is a dedicated museum in Montreal for Berliner ( Musée des ondes Emile Berliner ). Early disc recordings were produced in a variety of speeds ranging from 60 to 130 rpm, and

SECTION 50

#1732783102789

5460-558: The Waldorf-Astoria Hotel was front-page news in The New York Times , which reported: The audience broke into applause ... John Philip Sousa [said]: '[Gentlemen], that is a band. This is the first time I have ever heard music with any soul to it produced by a mechanical talking machine' ... The new instrument is a feat of mathematics and physics. It is not the result of innumerable experiments, but

5565-414: The base-10 logarithm of the ratio of the measured quantity to reference value. Thus, the ratio of P (measured power) to P 0 (reference power) is represented by L P , that ratio expressed in decibels, which is calculated using the formula: The base-10 logarithm of the ratio of the two power quantities is the number of bels. The number of decibels is ten times the number of bels (equivalently,

5670-414: The gains of amplifiers, attenuation of signals, and signal-to-noise ratios are often expressed in decibels. The decibel originates from methods used to quantify signal loss in telegraph and telephone circuits. Until the mid-1920s, the unit for loss was miles of standard cable (MSC). 1 MSC corresponded to the loss of power over one mile (approximately 1.6 km) of standard telephone cable at

5775-399: The impedance is constant. Taking voltage as an example, this leads to the equation for power gain level L G : where V out is the root-mean-square (rms) output voltage, V in is the rms input voltage. A similar formula holds for current. The term root-power quantity is introduced by ISO Standard 80000-1:2009 as a substitute of field quantity . The term field quantity

5880-415: The impedance is frequency- or time-dependent, this relationship does not hold in general, for example if the energy spectrum of the waveform changes. For differences in level, the required relationship is relaxed from that above to one of proportionality (i.e., the reference quantities P 0 and F 0 need not be related), or equivalently, must hold to allow the power level difference to be equal to

5985-608: The "B" side. In the 1990s Rhino Records issued a series of boxed sets of 78-rpm reissues of early rock and roll hits, intended for owners of vintage jukeboxes . The records were made of vinyl, however, and some of the earlier vintage 78-rpm jukeboxes and record players (the ones that were pre-war) were designed with heavy tone arms to play the hard slate-impregnated shellac records of their time. These vinyl Rhino 78s were softer and would be destroyed by old juke boxes and old record players, but play well on newer 78-capable turntables with modern lightweight tone arms and jewel needles. As

6090-539: The 1880s. Emile Berliner improved the quality of recordings while his manufacturing associate Eldridge R. Johnson , who owned a machine shop in Camden, New Jersey , eventually improved the mechanism of the gramophone with a spring motor and a speed regulating governor, resulting in a sound quality equal to Edison's cylinders. Abandoning Berliner's "Gramophone" trademark for legal reasons in the United States, Johnson's and Berliner's separate companies reorganized in 1901 to form

6195-459: The IEC or ISO. The IEC Standard 60027-3:2002 defines the following quantities. The decibel (dB) is one-tenth of a bel: 1 dB = 0.1 B . The bel (B) is 1 ⁄ 2  ln(10) nepers : 1 B = 1 ⁄ 2 ln(10) Np . The neper is the change in the level of a root-power quantity when the root-power quantity changes by a factor of e , that is 1 Np = ln(e) = 1 , thereby relating all of

6300-520: The United States Armed Forces produced thousands of 12-inch vinyl 78 rpm V-Discs for use by the troops overseas. After the war, the use of vinyl became more practical as new record players with lightweight crystal pickups and precision-ground styli made of sapphire or an exotic osmium alloy proliferated. In late 1945, RCA Victor began offering "De Luxe" transparent red vinylite pressings of some Red Seal classical 78s, at

6405-778: The available groove length divided by the turntable speed. Total groove length in turn depends on how closely the grooves are spaced, in addition to the record diameter. At the beginning of the 20th century, the early discs played for two minutes, the same as cylinder records. The 12-inch disc, introduced by Victor in 1903, increased the playing time to three and a half minutes. Because the standard 10-inch 78 rpm record could hold about three minutes of sound per side, most popular recordings were limited to that duration. For example, when King Oliver 's Creole Jazz Band, including Louis Armstrong on his first recordings, recorded 13 sides at Gennett Records in Richmond, Indiana, in 1923, one side

SECTION 60

#1732783102789

6510-426: The bandwidth of the original recording. Some frequency equalizations (for instance RIAA ) are implemented. This project aims to retrieve and archive the sound as close as possible to the original one. By default, audio restoration is not applied. The ultimate goal of this project is getting sound out of an otherwise forever lost record. Many records from the 1940s are cracked and definitely unplayable. The result

6615-462: The corner, looking all sad." During the first half of the 1920s, engineers at Western Electric , as well as independent inventors such as Orlando Marsh , developed technology for capturing sound with a microphone , amplifying it with vacuum tubes (known as valves in the UK ), and then using the amplified signal to drive an electromechanical recording head. Western Electric's innovations resulted in

6720-401: The decibel in underwater acoustics leads to confusion, in part because of this difference in reference value. Sound intensity is proportional to the square of sound pressure. Therefore, the sound intensity level can also be defined as: The human ear has a large dynamic range in sound reception. The ratio of the sound intensity that causes permanent damage during short exposure to that of

6825-441: The earliest days of the telephone, the need for a unit in which to measure the transmission efficiency of telephone facilities has been recognized. The introduction of cable in 1896 afforded a stable basis for a convenient unit and the "mile of standard" cable came into general use shortly thereafter. This unit was employed up to 1923 when a new unit was adopted as being more suitable for modern telephone work. The new transmission unit

6930-525: The earliest jazz and military band recordings. The loudest instruments such as the drums and trumpets were positioned the farthest away from the collecting horn. Lillian Hardin Armstrong , a member of King Oliver's Creole Jazz Band , which recorded at Gennett Records in 1923, remembered that at first Oliver and his young second trumpet, Louis Armstrong , stood next to each other and Oliver's horn could not be heard. "They put Louis about fifteen feet over in

7035-600: The early machines and, for no other reason continued to be used. In 1912, the Gramophone Company set 78 rpm as their recording standard, based on the average of recordings they had been releasing at the time, and started selling players whose governors had a nominal speed of 78 rpm. By 1925, 78 rpm was becoming standardized across the industry. However, the exact speed differed between places with alternating current electricity supply at 60 hertz (cycles per second, Hz) and those at 50 Hz. Where

7140-429: The first 45 rpm single, 7 inches in diameter with a large center hole. The 45 rpm player included a changing mechanism that allowed multiple disks to be stacked, much as a conventional changer handled 78s. Also like 78s, the short playing time of a single 45 rpm side meant that long works, such as symphonies and operas, had to be released on multiple 45s instead of a single LP, but RCA Victor claimed that

7245-485: The first electrical discs during the spring of 1925. The first electrically recorded Victor Red Seal record was Chopin 's "Impromptus" and Schubert 's "Litanei" performed by pianist Alfred Cortot at Victor's studios in Camden, New Jersey . A 1926 Wanamaker's ad in The New York Times offers records "by the latest Victor process of electrical recording". It was recognized as a breakthrough; in 1930,

7350-403: The form of the compact disc , had gained a larger market share, and the record left the mainstream in 1991. Since the 1990s, records continue to be manufactured and sold on a smaller scale, and during the 1990s and early 2000s were commonly used by disc jockeys (DJs), especially in dance music genres. They were also listened to by a growing number of audiophiles . The phonograph record has made

7455-445: The formerly standard "78s" over the next decade. The late 1950s saw the introduction of stereophonic sound on commercial discs. The phonautograph was invented by 1857 by Frenchman Édouard-Léon Scott de Martinville. It could not, however, play back recorded sound, as Scott intended for people to read back the tracings, which he called phonautograms. Prior to this, tuning forks had been used in this way to create direct tracings of

7560-584: The interest in a non-contact approach. The idea of this recovery of the sound of old records through optical scanning started in the summer of 1999 in Lugano , among the technical manager of the Swiss National Sound Archives ( Fonoteca Nazionale ) Stefano S. Cavaglieri (creator and holder of the intellectual property, initiator of the project), the former director of M & C Management and Communications SA Pierre Hemmer (co-creator of

7665-466: The introduction of the LP record in 1948. In popular music, the time limit of 3 + 1 ⁄ 2 minutes on a 10-inch 78 rpm record meant that singers seldom recorded long pieces. One exception is Frank Sinatra 's recording of Rodgers and Hammerstein 's " Soliloquy ", from Carousel , made on 28 May 1946. Because it ran 7m 57s, longer than both sides of a standard 78 rpm 10-inch record, it

7770-480: The late 19th century, at first competing with earlier cylinder records. Price, ease of use and storage made the disc record dominant by the 1910s. The standard format of disc records became known to later generations as "78s" after their playback speed in revolutions per minute, although that speed only became standardized in the late 1920s. In the late 1940s new formats pressed in vinyl, the 45 rpm single and 33 rpm long playing "LP", were introduced, gradually overtaking

7875-421: The latter being the most prevalent format today. The phonograph record was the primary medium used for music reproduction throughout the 20th century. It had co-existed with the phonograph cylinder from the late 1880s and had effectively superseded it by around 1912. Records retained the largest market share even when new formats such as the compact cassette were mass-marketed. By the 1980s, digital media , in

7980-550: The mains supply was 60 Hz, the actual speed was 78.26 rpm: that of a 60 Hz stroboscope illuminating 92-bar calibration markings. Where it was 50 Hz, it was 77.92 rpm: that of a 50 Hz stroboscope illuminating 77-bar calibration markings. At least one attempt to lengthen playing time was made in the early 1920s. World Records produced records that played at a constant linear velocity , controlled by Noel Pemberton Billing 's patented add-on speed governor. Early recordings were made entirely acoustically,

8085-555: The name logit for "standard magnitudes which combine by multiplication", to contrast with the name unit for "standard magnitudes which combine by addition". In April 2003, the International Committee for Weights and Measures (CIPM) considered a recommendation for the inclusion of the decibel in the International System of Units (SI), but decided against the proposal. However, the decibel

8190-436: The new high-speed changer rendered side breaks so brief as to be inconsequential. Early 45 rpm records were made from either vinyl or polystyrene . They had a playing time of eight minutes. At first the two systems were marketed in competition, in what was called " The War of the Speeds ". The older 78 rpm format continued to be mass-produced alongside the newer formats using new materials in decreasing numbers until

8295-416: The noise from a machine is measured (including the contribution of background noise) and found to be 87 dBA but when the machine is switched off the background noise alone is measured as 83 dBA. [...] the machine noise [level (alone)] may be obtained by 'subtracting' the 83 dBA background noise from the combined level of 87 dBA; i.e., 84.8 dBA.; in order to find a representative value of

8400-536: The number of audio channels ( mono , stereo , quad , etc.). The phrase broken record refers to a malfunction when the needle skips/jumps back to the previous groove and plays the same section over and over again indefinitely. The various names have included phonograph record (American English), gramophone record (British English), record, vinyl, LP (originally a trademark of Columbia Records ), black disc, album, and more informally platter, wax, or liquorice pizza. Manufacture of disc records began in

8505-423: The outside edge and ends near the center of the disc. The stored sound information is made audible by playing the record on a phonograph (or "gramophone", "turntable", or "record player"). Records have been produced in different formats with playing times ranging from a few minutes to around 30 minutes per side. For about half a century, the discs were commonly made from shellac and these records typically ran at

8610-449: The photography (film grain), or the scanning (dust, optics, CCD sensors). Then, the groove position is estimated using edge detection algorithms. Once the edges are detected, corrections requiring more complex knowledge about the structure of the image are carried out. Some examples of corrections: The final step is converting groove displacement into an audible signal. This signal is processed by band-pass filters in order to obtain only

8715-449: The process is photo shooting. It is performed at the beginning of the process on a properly cleaned record, in order to archive it as a film. The photographic film has a high resolution of 600 lines per mm . This resolution is sufficient to accurately follow the groove displacement. Once the record content is stored on a photographic film, the next step is to recover the original sound. The University of Applied Sciences of Fribourg built

8820-562: The project), and the Director of the Swiss National Sound Archives Pio Pellizzari (co-creator of the project). The Fribourg school of engineering and architecture ( Hochschule für Technik und Architektur Freiburg ) was the main partner, at first studying its feasibility and then starting a project that progressed over years. During normal playback of a phonograph record, sound is obtained by

8925-461: The quantities power spectral density and the associated root-power quantities via the Fourier transform , which allows elimination of the frequency dependence in the analysis by analyzing the system at each frequency independently. Since logarithm differences measured in these units often represent power ratios and root-power ratios, values for both are shown below. The bel is traditionally used as

9030-427: The ratio of any two powers is therefore ten times the common logarithm of that ratio. This method of designating the gain or loss of power in telephone circuits permits direct addition or subtraction of the units expressing the efficiency of different parts of the circuit ... In 1954, J. W. Horton argued that the use of the decibel as a unit for quantities other than transmission loss led to confusion, and suggested

9135-413: The record in the form of a rectangular picture of a ring. A second radial movement provides the next ring. Once digitized, the images are processed to analyze and determine the positions and displacement of the groove. The first step is to correct the imperfections of the captured images. Many disturbances can come from various stages of the acquisition process: the record itself (cracks, scratches, dust),

9240-459: The root-power level difference from power P 1 and F 1 to P 2 and F 2 . An example might be an amplifier with unity voltage gain independent of load and frequency driving a load with a frequency-dependent impedance: the relative voltage gain of the amplifier is always 0 dB, but the power gain depends on the changing spectral composition of the waveform being amplified. Frequency-dependent impedances may be analyzed by considering

9345-493: The same name. Electrical recording and reproduction have combined to retain vitality and color in recitals by proxy. The Orthophonic Victrola had an interior folded exponential horn, a sophisticated design informed by impedance-matching and transmission-line theory, and designed to provide a relatively flat frequency response. Victor's first public demonstration of the Orthophonic Victrola on 6 October 1925, at

9450-533: The same vein of Tin Pan Alley revivals, R. Crumb & His Cheap Suit Serenaders issued a number of 78-rpm singles on their Blue Goose record label. The most familiar of these releases is probably R. Crumb & His Cheap Suit Serenaders' Party Record (1980, issued as a "Red Goose" record on a 12-inch single), with the double-entendre " My Girl's Pussy " on the "A" side and the X-rated "Christopher Columbus" on

9555-406: The second session, on 30 April, the two 12-inch recordings were longer: "Embraceable You" was 4m 05s; "Serenade to a Shylock", 4m 32s. Another way to overcome the time limitation was to issue a selection extending to both sides of a single record. Vaudeville stars Gallagher and Shean recorded "Mr. Gallagher and Mr. Shean", written by themselves or, allegedly, by Bryan Foy, as two sides of

9660-420: The sound level in a room a number of measurements are taken at different positions within the room, and an average value is calculated. [...] Compare the logarithmic and arithmetic averages of [...] 70 dB and 90 dB: logarithmic average = 87 dB; arithmetic average = 80 dB. Addition on a logarithmic scale is called logarithmic addition , and can be defined by taking exponentials to convert to

9765-471: The sound was collected by a horn and piped to a diaphragm , which vibrated the cutting stylus. Sensitivity and frequency range were poor, and frequency response was irregular, giving acoustic recordings an instantly recognizable tonal quality. A singer almost had to put their face in the recording horn. A way of reducing resonance was to wrap the recording horn with tape. Even drums, if planned and placed properly, could be effectively recorded and heard on even

9870-641: The summer of 1958 in the U.S., and in a few countries, such as the Philippines and India (both countries issued recordings by the Beatles on 78s), into the late 1960s. For example, Columbia Records ' last reissue of Frank Sinatra songs on 78 rpm records was an album called Young at Heart , issued in November 1954. Columbia and RCA Victor each pursued their R&D secretly. The commercial rivalry between RCA Victor and Columbia Records led to RCA Victor's introduction of what it had intended to be

9975-510: The system: Among the unique audio files recovered with such techniques, the speech of Italian politician and poet Aldo Spallicci . Phonograph record A phonograph record (also known as a gramophone record , especially in British English) or a vinyl record (for later varieties only) is an analog sound storage medium in the form of a flat disc with an inscribed, modulated spiral groove. The groove usually starts near

10080-399: The units as nondimensional natural log of root-power-quantity ratios, 1 dB =  0.115 13 ... Np =  0.115 13 ... . Finally, the level of a quantity is the logarithm of the ratio of the value of that quantity to a reference value of the same kind of quantity. Therefore, the bel represents the logarithm of a ratio between two power quantities of 10:1, or the logarithm of

10185-426: The vibrations of sound-producing objects, as by English physicist Thomas Young in 1807. In 1877, Thomas Edison invented the first phonograph , which etched sound recordings onto phonograph cylinders . Unlike the phonautograph, Edison's phonograph could both record and reproduce sound, via two separate needles, one for each function. The first commercially sold disc records were created by Emile Berliner in

10290-599: Was 1.056 TU. In 1928, the Bell system renamed the TU into the decibel, being one tenth of a newly defined unit for the base-10 logarithm of the power ratio. It was named the bel , in honor of the telecommunications pioneer Alexander Graham Bell . The bel is seldom used, as the decibel was the proposed working unit. The naming and early definition of the decibel is described in the NBS Standard's Yearbook of 1931: Since

10395-435: Was 2:09 and four sides were 2:52–2:59. In January 1938, Milt Gabler started recording for Commodore Records , and to allow for longer continuous performances, he recorded some 12-inch discs. Eddie Condon explained: "Gabler realized that a jam session needs room for development." The first two 12-inch recordings did not take advantage of their capability: "Carnegie Drag" was 3m 15s; "Carnegie Jump", 2m 41s. But at

10500-624: Was gaining in popularity, too, and Columbia issued its first 45s in February 1951. By 1954, 200 million 45s had been sold. Eventually the 12-inch (300 mm) 33 + 1 ⁄ 3  rpm LP prevailed as the dominant format for musical albums, and 10-inch LPs were no longer issued. The last Columbia Records reissue of any Frank Sinatra songs on a 10-inch LP record was an album called Hall of Fame , CL 2600, issued on 26 October 1956, containing six songs, one each by Tony Bennett , Rosemary Clooney , Johnnie Ray , Frank Sinatra , Doris Day , and Frankie Laine . The 45 rpm discs also came in

10605-544: Was issued on 7 December 1959. The Seeburg Corporation introduced the Seeburg Background Music System in 1959, using a 16 + 2 ⁄ 3  rpm 9-inch record with 2-inch center hole. Each record held 40 minutes of music per side, recorded at 420 grooves per inch. From the mid-1950s through the 1960s, in the U.S. the common home record player or "stereo" (after the introduction of stereo recording) would typically have had these features:

10710-547: Was not until the LP era that an entire album of material could be included on a single record. In 1968, when the hit movie Thoroughly Modern Millie was inspiring revivals of Jazz Age music, Reprise planned to release a series of 78-rpm singles from their artists on their label at the time, called the Reprise Speed Series. Only one disc actually saw release, Randy Newman 's "I Think It's Going to Rain Today",

10815-506: Was released on Columbia 's Masterwork label (the classical division) as two sides of a 12-inch record. In the 78 era, classical-music and spoken-word items generally were released on the longer 12-inch 78s, about 4–5 minutes per side. For example, on 10 June 1924, four months after the 12 February premier of Rhapsody in Blue , George Gershwin recorded an abridged version of the seventeen-minute work with Paul Whiteman and His Orchestra. It

10920-490: Was released on two sides of Victor 55225 and ran for 8m 59s. "Record albums" were originally booklets containing collections of multiple disc records of related material, the name being related to photograph albums or scrap albums. German record company Odeon pioneered the album in 1909 when it released the Nutcracker Suite by Tchaikovsky on four double-sided discs in a specially designed package. It

11025-583: Was worked out on paper in advance of being built in the laboratory ... The new machine has a range of from 100 to 5,000 [cycles per second], or five and a half octaves ... The 'phonograph tone' is eliminated by the new recording and reproducing process. Sales of records plummeted precipitously during the early years of the Great Depression of the 1930s, and the entire record industry in America nearly foundered. In 1932, RCA Victor introduced

#788211