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High Com
The High Com (also as HIGH COM, both written with a thin space) noise reduction system was developed by Telefunken, Germany, in the 1970s as a high quality high compression analogue compander for audio recordings. High Com The idea of a compander for consumer devices was based on studies of a fixed two-band compander by Jürgen Wermuth of AEG-Telefunken ELA, Wolfenbüttel, developer of the Telefunken (formally abbreviated as "TEL" in professional broadcasting) four-band audio compander for professional use. In April 1974, the resulting "RUSW-200" prototype first led to the development of a sliding two-band compander by Ernst F. Schröder of Telefunken Grundlagenlaboratorium, Hannover since July 1974. However, the finally released High Com system, which was marketed by Telefunken since 1978, worked as a broadband 2:1:2 compander, achieving almost 15 dB of noise reduction for low and up to 20 dB RMS A-weighted for higher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noise Reduction System
Noise reduction is the process of removing noise from a signal. Noise reduction techniques exist for audio and images. Noise reduction algorithms may distort the signal to some degree. Noise rejection is the ability of a circuit to isolate an undesired signal component from the desired signal component, as with common-mode rejection ratio. All signal processing devices, both analog and digital, have traits that make them susceptible to noise. Noise can be random with an even frequency distribution (white noise), or frequency-dependent noise introduced by a device's mechanism or signal processing algorithms. In electronic systems, a major type of noise is ''hiss'' created by random electron motion due to thermal agitation. These agitated electrons rapidly add and subtract from the output signal and thus create detectable noise. In the case of photographic film and magnetic tape, noise (both visible and audible) is introduced due to the grain structure of the medium. In photograp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calibration Tone
A reference tone is a pure tone corresponding to a known frequency, and produced at a stable sound pressure level (volume), usually by specialized equipment. In media The most common reference tone in audio engineering is a at −20 dB. It is meant to be used by audio engineers in order to adjust the playback equipment so that the accompanying media is at a comfortable volume for the audience. In video production, this tone is usually accompanied by a test card so the video programming may be calibrated as well. It is sometimes played in sequence between a 100 Hz and 10 kHz tone to ensure an accurate response from the equipment at varying audio frequencies. This is also the "bleep" tone commonly used to censor obscene or sensitive audio content. In music Many electronic tuners used by musicians emit a tone of 440Hz, corresponding to a pitch of A above Middle C (A4). More sophisticated tuners offer a choice of other reference pitches to account for differences in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elektro-Mess-Technik
Elektromesstechnik (EMT) is a manufacturer of phonograph turntables and professional audio equipment, including a well-regarded line of artificial reverberation devices beginning with the EMT 140 plate reverb. The company was founded by Wilhelm Franz. Founding Wilhelm Franz, born in Bremen in 1913, founded Elektromesstechnik Wilhelm Franz K.G. in Berlin in 1938. Two years later Wilhelm’s brother, Walter, joined the company. The Allied bombing air raids over Berlin intensified in 1943 and Franz moved to Schuttertal, then, after 1945, to Lahr, in the Schwarzwald region of south-western Germany. The logo of an 'arrowhead' was chosen as a symbol of the passage of an electric signal in an electronic circuitry. Reverb effects 140 Plate Reverb In 1957, EMT introduced the ’140’ Reverberation Unit, an electro-mechanical reverberation device that offered an alternative to the spring reverbs and echo chambers of the era. The EMT 140 used a 1 meter-tall by 2 meters-wide steel plate h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noise Power
In telecommunication, the term noise power has the following meanings: # The measured total noise in a given bandwidth at the input or output of a device when the signal is not present; the integral of noise spectral density over the bandwidth # The power generated by a random electromagnetic process. # Interfering and unwanted power in an electrical device or system. # In the acceptance testing of radio transmitters, the mean power supplied to the antenna transmission line by a radio transmitter when loaded with noise having a Gaussian amplitude-vs.-frequency Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ... distribution. References Telecommunication theory Noise (electronics) {{telecomm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A-weighted
A-weighting is the most commonly used of a family of curves defined in the International standard IEC 61672:2003 and various national standards relating to the measurement of sound pressure level. A-weighting is applied to instrument-measured sound levels in an effort to account for the relative loudness perceived by the human ear, as the ear is less sensitive to low audio frequencies. It is employed by arithmetically adding a table of values, listed by octave or third-octave bands, to the measured sound pressure levels in dB. The resulting octave band measurements are usually added (logarithmic method) to provide a single A-weighted value describing the sound; the units are written as dB(A). Other weighting sets of values – B, C, D and now Z – are discussed below. The curves were originally defined for use at different average sound levels, but A-weighting, though originally intended only for the measurement of low-level sounds (around 40 phon), is now commonly used for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root Mean Square
In mathematics and its applications, the root mean square of a set of numbers x_i (abbreviated as RMS, or rms and denoted in formulas as either x_\mathrm or \mathrm_x) is defined as the square root of the mean square (the arithmetic mean of the squares) of the set. The RMS is also known as the quadratic mean (denoted M_2) and is a particular case of the generalized mean. The RMS of a continuously varying function (denoted f_\mathrm) can be defined in terms of an integral of the squares of the instantaneous values during a cycle. For alternating electric current, RMS is equal to the value of the constant direct current that would produce the same power dissipation in a resistive load. In estimation theory, the root-mean-square deviation of an estimator is a measure of the imperfection of the fit of the estimator to the data. Definition The RMS value of a set of values (or a continuous-time waveform) is the square root of the arithmetic mean of the squares of the values, or th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noise Reduction
Noise reduction is the process of removing noise from a signal. Noise reduction techniques exist for audio and images. Noise reduction algorithms may distort the signal to some degree. Noise rejection is the ability of a circuit to isolate an undesired signal component from the desired signal component, as with common-mode rejection ratio. All signal processing devices, both analog and digital, have traits that make them susceptible to noise. Noise can be random with an even frequency distribution (white noise), or frequency-dependent noise introduced by a device's mechanism or signal processing algorithms. In electronic systems, a major type of noise is ''hiss'' created by random electron motion due to thermal agitation. These agitated electrons rapidly add and subtract from the output signal and thus create detectable noise. In the case of photographic film and magnetic tape, noise (both visible and audible) is introduced due to the grain structure of the medium. In photograp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 101/10 (approximately ) or root-power ratio of 10 (approximately ). The unit expresses a relative change or an absolute value. In the latter case, the numeric value expresses 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 a power ratio, it is defined as ten times the logarithm in 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 ''ampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hannover
Hanover (; german: Hannover ; nds, Hannober) is the capital and largest city of the German States of Germany, state of Lower Saxony. Its 535,932 (2021) inhabitants make it the List of cities in Germany by population, 13th-largest city in Germany as well as the fourth-largest city in Northern Germany after Berlin, Hamburg and Bremen. Hanover's urban area comprises the towns of Garbsen, Langenhagen and Laatzen and has a population of about 791,000 (2018). The Hanover Region has approximately 1.16 million inhabitants (2019). The city lies at the confluence of the River Leine and its tributary the Ihme, in the south of the North German Plain, and is the largest city in the Hannover–Braunschweig–Göttingen–Wolfsburg Metropolitan Region. It is the fifth-largest city in the Low German dialect area after Hamburg, Dortmund, Essen and Bremen. Before it became the capital of Lower Saxony in 1946, Hannover was the capital of the Principality of Calenberg (1636–1692), the Electorat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolfenbüttel
Wolfenbüttel (; nds, Wulfenbüddel) is a town in Lower Saxony, Germany, the administrative capital of Wolfenbüttel District. It is best known as the location of the internationally renowned Herzog August Library and for having the largest concentration of timber-framed buildings in Germany. It is an episcopal see of the Evangelical Lutheran Church in Brunswick. It is also home to the Jägermeister distillery, houses a campus of the Ostfalia University of Applied Sciences, and the Landesmusikakademie of Lower Saxony. Geography The town center is located at an elevation of on the Oker river near the confluence with its Altenau tributary, about south of Brunswick and southeast of the state capital Hannover. Wolfenbüttel is situated about half-way between the Harz mountain range in the south and the Lüneburg Heath in the north. The Elm-Lappwald Nature Park and the Asse hill range stretch east and southeast of the town. With a population of about 52,000 people, Wolfe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S (unit)
The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of Units ( SI) is more precise:The second ..is defined by taking the fixed numerical value of the caesium frequency, Δ''ν''Cs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be when expressed in the unit Hz, which is equal to s−1. This current definition was adopted in 1967 when it became feasible to define the second based on fundamental properties of nature with caesium clocks. Because the speed of Earth's rotation varies and is slowing ever so slightly, a leap second is added at irregular intervals to civil time to keep clocks in sync with Earth's rotation. Uses Analog clocks and watches often have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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