Microphone
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Vocal(for karaoke). In accordance with the name, such models are intended primarily for the transmission of the human voice — during singing, artistic reading, etc., when not only speech intelligibility is important, but also shades of intonation. It is these microphones that can be seen on stage during concerts and other similar events, in karaoke equipment, etc. This category also includes models that can also be used as instrumental ones (see below).
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Buttonhole. The name of this type of microphones is due to the traditional method of fastening — on the collar, where the buttonhole is usually located; they have miniature size and the presence of a clip for holding on clothes. Such devices are known primarily as television transmission equipment — they are used by participants in television programs so that they can speak without using their hands with larger microphones. And some devices of this type are actually a “headset blank”, which turns into a full-fledged headset when headphones are connected.
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For a computer. Microphones designed for use with full size PCs. Such microphones usually have a capsule on a long stem, sometimes flexible (see below) and a stand for placement on a table surface. Their main purpose is voice communication using a computer, where the most important thing is not so much the accuracy of the transfer of details, but
...the data transfer rate and their small volumes — therefore, the sound quality, usually, is relatively low.
— For a laptop. Like the PC microphones described above, "laptop" models are designed mainly for voice communication and have rather modest characteristics. Their key difference is the focus on use with portable devices, which is expressed primarily in compact size. In addition, for many of these microphones, the connection port also acts as a mount for placement on a laptop case.
— Instrumental. Microphones designed to mimic musical instruments such as saxophones, acoustic guitars (not equipped with pickups), percussion kits, etc. Note that despite the outward resemblance of some models to the vocal ones described above, “purely instrumental” microphones for voice processing are poorly suited, it is not recommended to use them for this purpose.
— Studio. Microphones designed for use in recording studios. Usually, they are designed for recording vocals. Differ in high quality of a sound transmission and the corresponding cost.
— Head. Microphones designed to be worn on the head — like headsets (only in this case there is no earpiece in the design). They are miniature in size and are similar in application to lavaliers (see above), but are located closer to the mouth and do not depend on the speaker's clothing. This allows the use of such models in specific situations where a lavalier microphone is unsuitable — for example, for filming a video with a strong level of extraneous noise.
— For conferences. Microphones intended for use in conference rooms, huddle rooms, grandstands, and similar locations. The design of such models can be different — a capsule on a flexible leg (see below), a disc placed directly on the table, etc. However, anyway, this variety is optimized for speech transmission and is designed for the maximum convenience of the speaker — so that the user is not distracted by choosing the optimal position relative to the microphone and the distance to it.
— For a video camera. Microphones designed, as the name suggests, for use with video cameras, primarily professional ones. Note that technically, any microphone can be connected to the input of the video camera, matching the connectors and main characteristics; however, this category only includes models that are designed to mount directly into a special mount on the camera body.
— For a voice recorder. A specific type of microphone designed exclusively for use with voice recorders. Such equipment, usually, is equipped with its own built-in microphones, but their capabilities may not be enough in some cases; and among high-end professional voice recorders there are devices that do not have a microphone at all. External microphones are usually connected via a 3.5 mm mini-Jack interface or via a proprietary connector (see below), while one of their distinguishing features is the absence of a wire: the plug is mounted directly on the microphone body and plays the role of not only a connector, but also a mount. Of course, miniature sizes are also characteristic of such devices.
— For phone/tablet. This category includes specialized microphones, originally positioned as accessories for smartphones or tablets. Usually, they are similar to the voice recorders described above in the sense that they are attached directly to the body of the device without using additional wires. Their main specificity, compared to the same models for voice recorders, is the connection method — usually a universal connector is used for this, like 30pin / Lightning, microUSB or a proprietary interface (see below for more details).
— For video production. Microphones intended for use in video recording. In fact, this variety includes two subgroups, each with its own specialization. The first is microphones, which can be conditionally called "reporter's". Usually, these include dynamic (see "Type") models with all-round directivity (see below) and good sensitivity. These features allow you to "hear" not only the voice of the reporter, but also the sound background around him; in addition, you do not need to accurately maintain the position of the microphone relative to the face, which is especially useful when interviewing other people. Also, "reporter" models have durable cases and are generally well protected from various troubles (although they are not necessarily completely moisture and shock resistant). The second variety of models for video production is “sound operator”: such microphones can often be seen on film sets mounted on long rods. They, in turn, are usually made unidirectional or bidirectional (for maximum filtering of extraneous sounds), and most often they are condenser types and provide a fairly high quality and reliability of sound transmission.
— Suspended. Microphones designed to be suspended, such as from the ceiling. Such models are intended mainly for choir singing, theatrical performances and other situations in which other types of microphones (standing on a stand, held in the hand or even clinging to the head) are not very convenient.
— Measuring. Measuring microphones are designed to calibrate sound installations. With their help, you can quickly and accurately adjust the loudness for a musical instrument, loudspeaker, sound recording equipment, etc. The key features of measuring microphones are a wide frequency range (20 – 40,000 Hz) and high frequency response stability. The measuring microphone measures the noise level and detects sound anomalies. Properly tuned, with the help of a measuring microphone, the sound installation will fully correspond to the acoustic features of a particular room.Operating principle
- Dynamic. “Conventional,” or coil,
dynamic microphones use a system of a diaphragm (membrane) and a coil that is placed in a magnetic field. From sound vibrations, the membrane, and with it the coil, begin to move, and an electrical signal is generated in the coil. Such models are relatively inexpensive, durable and reliable, and also cope well even with very loud and harsh sounds; in addition, they are more compact and lighter than the other type of dynamic microphones - ribbons (see below). Their main disadvantage is poor efficiency at high frequencies.
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Dynamic (tape). A variation of the dynamic microphones described above, in which the membrane is connected not to a coil, but to a thin (several microns) metal tape, hence the name. Historically, this is the first type of microphone with a dynamic operating principle, however, due to a number of shortcomings, it gradually lost wide popularity, giving way to coil-based options. Such disadvantages are, first of all, large size and large mass, complexity and high cost of production, as well as very low output impedance, which complicates the work with amplifiers. At the same time, tape models are characterized by extremely high accuracy of sound transmission over the entire frequency range, which allows them to be used in recording studios, at high-profile concerts, etc. Most modern models of this type are professional models, in particular studi
...o ones (see “Purpose”).
— Condenser. The name of this type is due to the fact that the microphone is actually a capacitor, in which the role of one of the plates is played by a sensitive membrane (usually made of a metallized polymer). Due to the vibration of the membrane (under the influence of sound vibrations), the distance between the plates and, accordingly, the capacitance of the capacitor changes - these fluctuations in capacitance provide an electrical signal. Condenser microphones have uniform sound transmission over the entire frequency range, with a minimum of distortion, due to which this technology has found wide application in professional audio equipment. It is worth considering that for such a device to operate, additional power is required - the so-called. “phantom” (standard voltage - 48 V). However, this cannot be called a clear disadvantage, because amplifiers, receivers and other high-end equipment are often made with this requirement in mind. But obvious disadvantages include high price, sensitivity to shock and strict requirements for temperature and humidity; the latter makes condenser microphones poorly suited for outdoor use.
— Capacitor (tube). A specific type of condenser microphones described above. They use the same principle of sound production (with all the advantages and disadvantages), however, the amplification element in such models, in accordance with the name, is built on vacuum tubes. Technically, such an amplifier introduces more distortion into the signal than a transistor one, but this distortion gives the sound a characteristic coloring that is pleasant to many listeners. Simply put, you get that notorious “warm tube sound”; Moreover, achieving such an effect using a microphone is cheaper than using a tube amplifier, and for a number of technical reasons this option often turns out to be optimal. Almost all tube microphones have a studio purpose (see above). Their main drawback is their high price (several times more than that of “regular” capacitor analogues). In addition, such models have their own nutritional characteristics; To supply energy, a special adapter is usually supplied, which is also responsible for controlling additional functions such as changing the radiation pattern.
- Electret. In design, such microphones are similar to the condenser ones described above, but their design includes a plate made of the so-called. electret - substances with special electrical properties. This provides a number of advantages: electret microphones can be used outdoors without much difficulty, they can be made more compact, and such models are cheaper to produce; At the same time, the quality of sound transmission can be quite comparable to condenser ones. As a result, this technology is found in a wide variety of models - from miniature lavaliers and simple computer ones to studio ones (see “Purpose”). Note also that electret microphones also require external power, but this is not always phantom 48 V - for some varieties, a small amount of energy is sufficient, which can be provided by a compact battery or power supply via a 3.5 mm mini-Jack cable.Rated resistance
Microphone AC impedance; this parameter is also called "impedance". This is one of the most important characteristics that determines compatibility with the amplifier or other device to which the microphone is connected: if the impedance is not optimal, there may be a loss in signal power. It has its own characteristics, depending on the purpose of a particular model (see above). So, for microphones used with computers, laptops, voice recorders and phones / tablets, the impedance may not be indicated at all — the characteristics of such models are selected in such a way as to ensure normal compatibility with the corresponding devices. But in professional audio equipment, special rules are used for selection; more details can be found in special sources.
Frequency range
The range of audio frequencies normally perceived and processed by a microphone.
The wider this range — the fuller the signal, the less likely that too high or low frequencies will be missed due to the imperfection of the microphone. However, in this case, it is worth considering some nuances. First of all: a wide frequency range in itself does not guarantee high sound quality — a lot also depends on the type of microphone (see above) and its frequency response, not to mention the quality of other components of the audio system. In addition, a large width is also not always really necessary. For example, for normal transmission of human speech, a range of 500 Hz — 2 kHz is considered sufficient, which is much narrower than the general range perceived by the human ear. This general range, in turn, averages from 16 Hz to 22 kHz, and also narrows with age. Do not forget about the features of the equipment to which the microphone is connected: it is hardly worth specifically looking for a model with an extensive range, if, for example, the amplifier to which it is planned to be connected severely “cuts off” the frequencies from above and/or below.
Sensitivity
Sensitivity describes the signal strength at the output of a microphone when it processes a sound of a certain volume. In this case, sensitivity means the ratio of the output voltage to the sound pressure on the membrane, expressed in decibels. The higher this number, the higher the sensitivity. Note that, as a rule, values in decibels are negative, so we can say this: the closer the number is to zero, the more sensitive the microphone. For example, a -38 dB model outperforms a -54 dB model in this parameter.
It should be borne in mind that high sensitivity in itself does not mean high sound quality - it only allows the device to “hear” a weaker sound. Conversely, low sensitivity is not an unequivocal sign of a bad microphone. The choice for this parameter depends on the specifics of the application: a sensitive device is useful for working with low sounds and in cases where it is necessary to capture the smallest nuances of what is happening, and a “weak” microphone will be convenient at high sound volume or, if necessary, filter out extraneous weak noises. There are models with
sensitivity adjustment(and for models with a headphone output
, headphone volume control may be provided).
Sound pressure
The maximum sound pressure perceived by the microphone, at which the harmonic oscillation coefficient does not exceed 0.5% — in other words, the highest sound volume at which no noticeable interference occurs.
The higher this indicator, the better the microphone is suitable for working with loud sound. Here it is worth considering that the decibel is a non-linear quantity; in other words, an increase in volume from 10 dB to 20 dB or from 20 to 40 dB does not mean a 2-fold increase in volume. Therefore, when assessing, it is most convenient to refer to comparative tables of noise levels. Here are some examples: a level of 100 dB roughly corresponds to a motorcycle engine or subway car noise; 110 dB — helicopter; 120 dB — the work of a demolition hammer; 130 dB, comparable to the sound of a jet aircraft taking off, is considered a pain threshold for a person. At the same time, many high-end microphones are able to work normally at a sound pressure of 140 – 150 dB — and this is a noise level that can cause physical damage to a person.
Signal to noise ratio
A parameter that describes the relationship between the useful signal level and the noise level produced by the microphone. Note that the actual signal-to-noise ratio varies depending on the sound pressure perceived by the microphone. Therefore, in the characteristics it is customary to indicate the option for a standard situation — at a sound pressure of 94 dB. This allows you to compare different models with each other.
In general, this indicator quite clearly characterizes the quality of work of a particular model, since it takes into account almost all significant extraneous noise that occurs during operation. The greater this ratio, the clearer the sound is, the less distortion it has. Values of 64 – 66 dB are considered quite decent, and high-end microphones provide performance of 72 dB and higher.
ADC sampling rate
The sampling rate of the analogue-to-digital converter (ADC) provided in the design of the microphone.
An ADC is a module responsible for converting an analogue signal coming from a microphone capsule into a digital format. It is used mainly in models connected via digital interfaces — for example, USB (see below) — and also in some wireless ones, where the digital format is used for radio communication.
The principle of analogue-to-digital conversion is that the analogue signal is divided into separate fragments, each of which is encoded with its own numerical value. If this is depicted graphically, then the graph of the analogue signal looks like a smooth line, and the digital signal looks like a set of “steps” close to this line. The higher the sampling frequency, the more “steps” fall on a certain section of a smooth line and the more accurately the digital signal corresponds to the original analogue.
Thus, high values of this parameter indicate a high quality of the microphone. However, it must be said here that for normal restoration of the original signal from digital (in other words, for normal reproduction of the sound perceived by the microphone), a sampling frequency twice the maximum frequency of the received sound is considered sufficient. For pure human speech, indicators of 2.3 kHz are considered record-breaking, and harmonics that complement the timbre of the voice do not exceed 8 kHz in frequency. Thus, a high sampling rate...is not required for normal speech processing. At the same time, models intended for studio recording (see "Intended use") may have rather high values of this parameter — up to 96 kHz inclusive. This is due not only to the sound quality (although it is also important), but also to the technical aspects of processing and mixing.
Also note that upsampling affects the amount of data transmitted, so high performance is not always optimal. Thus, some microphones allow you to change the value of this parameter; for such models, our catalog indicates the maximum value of the sampling rate.
ADC bit depth
The bit depth of the analogue-to-digital converter (ADC) installed in the microphone.
An ADC is a module responsible for converting an analogue signal coming from a microphone capsule into a digital format. It is used mainly in models connected via digital interfaces — for example, USB (see below) — and also in some wireless ones, where the digital format is used for radio communication. For more information on this conversion, see ADC Sampling Rate. But if the sampling rate describes the number of “steps” of a digital signal in a certain area, then the bit depth determines the number of signal level options available for each individual step. The higher the bit depth, the more such options and the more accurately the digital signal level will correspond to the analogue level.
Thus, this parameter also directly affects the quality of the conversion. If we talk about specific values, then 16 bits is considered quite enough for professional studio microphones (see "Intended use"), and high-end models can also have 32-bit converters.