Microphone: what it is, species and characteristics, choice rules

To choose the right microphone, you must first determine what it is, how it works. Equally, it is important to figure out the types and characteristics of devices. And only after that you can formulate clear rules of choice, determine the best models.

What it is?

It is difficult to find a person who would not know what the microphone looks like, and what is its usual use. You can find a huge variety of such devices. But they all obey the general definition – electrical equipment. The sound wave coming to “entrance” is converted to an electrical signal. According to its characteristics, the other equipment will be able to reproduce the initial sound.

The microphone can broadcast sound on:

  • ordinary home columns;
  • computer;
  • television;
  • record player;
  • player;
  • concert equipment;
  • Studio sound recording equipment.

History of creation

Microphones in the XXI century are very advanced devices. But the highlights in their work were changed since the invention. It is believed that the first approach to the creation of the microphone did the French researcher du Monsiel. In 1856, he found that the graphite electrode can significantly change the degree of electrical resistance. For this you only need to slightly change the area of ​​contact of the conductors.

But the first practically working microphone invented and introduced Emil Berliner in 1877. A year later, another resident of the United States David Hughes modernized the initial design of Berliner. The membrane was added to one of the coal rods. The decisive step made the legendary Edison. It was he who came up with replacing the rods from coal to the powder coal mass; Such a solution continues to be applied in some devices today.

Only in 1916, and again in the United States, more precisely, a condenser scheme appears in Bell Labs. A few years later, the subspecies of condenser devices were presented in Japan – electret microphones. And in Germany create a dynamic microphone device. It has already been ahead of the characteristics and coal, and condenser models. And our compatriots Yakovlev and Rzhevkin in 1925 presented the world a piezoelectric scheme.

She won very high popularity, and is even actively used in hydrophones. In 1931, another move in the US. We developed there Dynamic type of microphone with coil. This device has excellent frequency parameters. No wonder he continues to apply on sound recording studios in different parts of our planet.

Device and principle of operation

In general, the microphone is pretty simple. And the scheme is also almost independent of the type of apparatus. When the sound is affected by a thin membrane, the movement of this membrane generates electrical waves. Depending on how the device works, the generation of electrical oscillations occurs due to:

  • changes of capacitance capacitors;
  • phenomena of electromagnetic induction;
  • piezoelectric process.

    In the description of how the microphone is made, it is important to emphasize that Its properties depend on the features of the interaction of sound and diaphragms. The microphone of pressure is called a device in which the sound wave presses only one of the sides of the diaphragm. Also used devices in which it affects the entire surface of the receiver.

    ATTENTION: On the second side of the diaphragm in pressure microphones, there are not straight waves, but those who have exposed to any resistance. This resistance can wear a mechanical, acoustic character, or to be created by time delay.

    In the latter case, it is said that this is an asymmetrical microphone with gradient pressure. The condenser microphone apparatus, except input, consists of more specially selected electrical capacitors. They are connected electrically sequentially to a DC source and load resistance.

    The structure of electret devices is different. Maintaining charge in them provides a layer of a special substance – an electric that is able to work for at least 20 years. Since they have a built-in transistor, the power supply is required from the outside. In this case, the polarizing voltage is not required. As for dynamic devices, they work in the same way as the speakers, but exactly the opposite. There is no need for phantom nutrition.

    Coil type It implies a rigid mechanical bunch of membrane with a special coil, which is placed inside the annular gap of the magnetic system.

    And also meet (but less often):

    • tape;
    • coal;
    • Optoacoustic;
    • piezoelectric;
    • Combined (combined solutions described above) devices.

    But it is useful to stay on some features of different devices. So, in the dynamic diaphragm system is connected to the coil and magnet. Together they form a small electricity generator. It works as if the sound actuator. To create a magnetic field surrounding the coil, a permanent magnet is used. A big power for it is not needed, in the first place reliability and accuracy of work.

    Dynamic microphones are relatively simple, and at the same time very reliable. They will be able to guarantee an excellent sound for almost any everyday task. Such systems can successfully work even with a very loud sound, which other acoustic equipment is very. Resistance to humidity and high temperature is also very important.

      Therefore, it is the dynamic microphone most often choose to organize massive street events.

      The condenser type is an assembly of a charged diaphragm and a fixed plate, and in general the design acts as a sound sensitive condenser. The membrane is usually done from the metal, although there are options when it is metallized, and the main part is made of plastic. An electret subspecies of the condenser microphone is usually used for sound.

      All such models include active contours, which allows you to coordinate the output of an element with basic microphone inputs.

      Characteristics

      The fundamentally important characteristic of the microphone is the so-called amplitude-frequency characteristic. For greater simplicity in documents and special texts, it is denoted as achd. Specialists and amateurs are also often interested in the focus of sound waves. But electrical characteristics and design features are not so important as it seems. For the condenser scheme, the phantom power supply parameters are fundamentally significant.

      It is worth paying attention to the so-called transitional response.

      It is not difficult to understand that Moving the diaphragm of the sound wave leads to the fact that this wave exists energy. And in the amount, the mass of the diaphragm and coils at the dynamic device is 1000 times higher than with a condenser version. Both the beginning of the movement and its ending is slower. It inevitably affects sound quality.

      Returning to Ahh, I must say that This is also the ratio of the output signal to the entire range of operating frequency. A rare manufacturer avoids the description of the frequency response, in general, it is usually given in some range. Most often use a graph showing the output level when the frequency changes. Color line graphic is usually characteristic of an extended range microphones. They do not distort a variety of sounds; Relief Ahh is not selected for the most accurate playback, but to solve strictly specific tasks.

      Additionally, it is worth assessing:

      • Decybel;
      • focus;
      • suppression of spatial noise;
      • swivel effect;
      • impedance;
      • Output electrical level.

      Views

      All microphones can be classified by several parameters.

      By destination

      Pretty wide application Find special pop microphones. Contrary to the name, they are actively used not only in the theater, at concerts. Such equipment is needed everywhere, where one or more people should hear a big mass of viewers in the hall. Past microphones can have different external execution. But they are necessarily fixed firmly in the rack holders.

      Reporter sound receiver, as it is not difficult to guess, is intended for journalists. And for other people who need to record (broadcast) own or someone else’s voice in various places. Of course, this is a mobile device, often with an autonomous power source. Such devices are usually calculated on the hidden wearing. Designers provide for the possibility of using them even in windy weather.

      Basic function Studio microphones – Operation in television studios. Most often it is flat and relatively low-challenging devices. The acoustic block in them is always high sensitivity. Large frequency range is not required, as the transfer of various sounds. Studio equipment works mainly with voices, but at the same time it should provide a clear, uninterrupted transmission.

      And here Studio broadcast microphone will be interesting not only for the TV channel, but also for the radio station. All similar devices are equipped with switches to easily change the direction of sound reception.

      Next important species – Microphone for recording in the studio. Usually it is mounted on specially prepared racks. Such equipment will perceive all the subtleties of the sound, even with serious interference.

      According to the principle of action

      Modern industry for the most part makes condenser and dynamic microphones. Other varieties can also be bought, but they are mostly needed for high-social tasks. The dynamic option has always perfect operating parameters. For the convenience and lack of need for power supply, it is appreciated both correspondents of television channels and singers, humorists, entertainers. But the condenser microphone gives a more pleasant sound, and it does not depend on the frequency.

      Head microphones are quite popular. They are fixed on the speaker’s head and usually have a very narrow orientation. Removal of foreign sounds is practically excluded. Such technique is widely used by actors, various instructors, commentators, heads of tourist groups, and so on.

      Lapel microphone, He is “Petchka”, as soon as possible, and is suitable for those cases when there is no desire to disturbing it.

      More models may still stand out:

      • for video filming (“guns”);
      • free;
      • stereo;
      • border layer (in demand in negotiations);
      • suspended;
      • goose necks;
      • Measuring microphones.

      Criterias of choice

      Correctly choose a good microphone, focusing only on the volume, is unlikely to succeed. It is very important to ask to show the product in action. If in the foreground, accurate sound reproduction, then you need to give preference to the condenser version. But it is possible to use such a solution only where the excess sound pressure will not affect the result of the recording. That’s why Outside studios, dynamic samples are most often used.

      Regardless of the fixation mechanism, it is necessary to deal with what the membrane size should be. Small-grained format is capable of very accurate and clearly register high frequencies. But it is very sensitive even to insignificant air fluctuations.

      A large-scale microphone with a smaller specific sensitivity due to the large reception area provides excellent susceptibility. Disadvantage only one – stronger echo.

      The advantages and disadvantages of medium-graded microphones determine quite difficult. They combine in different degrees of fine-grained and large-breeding equipment. Because each device needs to be approached with its special measure. As for the sensitivity of the microphone, then not everything is definitely. Very high sensitivity can interfere, if a room or another place for recording is well prepared.

      Unidirectional microphone can catch the waves emanating from one direction. It is recommended for operation at concerts, during theatrical performances. Bidirectional models (octal and some others) concentrate the sound coming from opposite sides. This solution is suitable for interviews on television or to record in a major concert hall. Immediately it turns out to record the audience’s response to the speech.

      The omnidirectional type of microphone will record sounds from all sides. Sound in this case the most natural. However, this technique is used only in well-equipped rooms. Outsided sounds extremely detrimentally affect records. In addition to the listed nuances, it is worth considering:

      • microphone power type;
      • view of its connector;
      • Volume control capabilities;
      • Ability to stop recording at all.

      Best models

      Of course, the number of attractive versions of microphones falls Sennheiser handMic Digital. Cute black color – by no means the only dignity of the dynamic hand microphone. He has a strong metal case. You can use the device for interviews and recording music through the iOS standard devices. APGEE specialists are attracted to the development of the model – one of the favorites of digital acoustics.

      Designers took care of preventing the prevention and exposure to side noise. The received recording is almost always possible to immediately publish. And in other cases it will be necessary only to edit audio recordings. Execution is very durable, the microphone is reliably protected from shock.

      Engineers did everything possible to minimize the tip from cell phones.

      Technical parameters are as follows:

      • cardioid diagram;
      • suspended equivalent noise level 74 dB;
      • No write off buttons;
      • microUSB format connector;
      • frequencies from 0.04 to 16 kHz;
      • permissible sound pressure up to 99 dB;
      • 2-meter USB cable.

        Attention deserves and model E835 of the same manufacturer. The design is optimally built so that the vocals and back-vocals can be sounded. Provide protection against sounds that are not running along the axis of the direction. There is also protection against reverse parasitic communication. There is an antishock suspension on the capsule; The silent switch is equipped with a retainer.

        Practical properties:

        • Balanced returns in all frequencies;
        • “Warm” balance on tones;
        • cardioid diagram;
        • Mute buttons no;
        • Rate of resistance 350 ohms;
        • the smallest load resistance of 1000 ohms;
        • XLR connector;
        • frequency processing from 40 to 16000 Hz;
        • Sensitivity level 2.7 mV / PA;
        • Range of operating temperatures from 0 to + 40 degrees Celsius.

          Enjoy and popular Videomic NTG. He is appreciated primarily for versatility. An annular linear tube with special perforation guarantees extraordinary transparency and naturalness of sound. Using digital switching, you can access the high frequency filter and the Special Security Channel. Implemented option PAD – 20 dB.

          Automatic yield with a diameter of 3.5 mm is great for attaching to the camcorder or mobile phone. Prevent arbitrary audio circumcision helps an updated, more comfortable indicator of the number of decibel. Upper frequency filter can be configured to 75 or 150 Hz. Strengthening is adjustable in continuously.

          Condensatory microphone accurately deserves attention Rode TF-5 with low diaphragm. It is characterized by a cardioid diagram of the sound. The capsule was constructed again. In its design, the accuracy of parts is less micron. The manufacturer promises the impressive clarity of sound and its unique warmth.

          Even other RODE microphones with a small diaphragm noticeably inferior to the TF-5 models. Guaranteed very clear, “air” sound. Saturation is added to it with warm colors. Sound pairing is very kindly performed.

          The device is recommended as a stereo pair in the most difficult records, as well as when capturing the finest nuances of the sound.

          Another attractive model – SHURE 55SH SERIES II. The design is made consciously in the stylistics of the 1950s-60s. In this case, the housing of the dynamic microphone is quite modern. It allows you to reproduce the most common vocal without any problems. Cardioid diagram of sounding helps this very much. The range of processed frequencies is from 50 Hz to 15 kHz.

          Other parameters:

          • Successful testing of speech;
          • Impedance declared 150 ohms (according to experts, 270 ohms);
          • Standard XLR connector;
          • Open circuit voltage at a frequency of 1000 Hz – 58 dB;
          • chromed cast housing;
          • Resistance at the inlet 75-300 ohms;
          • Dimensions 5.6×18.8×7.8 cm.

            Complete the review stands on the model Shure Beta 87. The manufacturer positions its development as the “ideal condenser microphone for vocal”. He will be able to transfer all the richness of sounds, avoiding offside additives. Frequency response of the signal as possible. The design is different:

            • increased resistance to noise;
            • in demand among professional performers;
            • extended frequency scatter (0.05-18 kHz);
            • unidirectional supercardoid diagram;
            • electrical resistance 150 ohms;
            • output signal at 74 dB.

            In the next video you will learn how to choose the right microphone to shoot a video on a smartphone.

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