Comparison Trust Flex USB vs Trust GXT 210 USB

- 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.

— 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.

Directionality describes the ability of a microphone to pick up sounds coming from different directions, more precisely, the dependence of sensitivity on the direction from which the sound comes.

— Unidirectional. As the name implies, these microphones are capable of picking up sound coming from only one side. Note that the coverage area itself can be quite wide, but anyway it is located “in front” of the microphone. Unidirectional models are very convenient for the perception of sound from a single source, with maximum clipping of ambient noise.

— Bidirectional. This term in our case means two types of microphones. The first option is the classic bidirectional models, designed for the possibility of normal perception of sound from two opposite sides — roughly speaking, "front" and "rear"; at the same time, dead zones are formed on the sides, from where the sound is practically not perceived. This format of work can be useful, for example, for broadcasting a dialogue in a radio station studio, or when simultaneously recording two voices on one microphone. The second variety is microphones with a pair of capsules directed at an angle to each other (most often perpendicular); a similar design is used in models with a stereo recording function.

— Omnidirectional. Also, this variety is called "non-directional", which also to a certain extent ch...aracterizes its features. Such microphones do not have a clearly defined directionality — they perceive the sound coming from any direction with full sensitivity. An example of a situation where this format might be useful is a recording of a roundtable discussion.

Note that while most microphones only work in one directional pattern, some models support multiple directional patterns, with the ability to switch between them as desired by the user (see Features/Characteristics). The methods of such switching can be different: in some models it is enough to move the switch, in others you need to change the capsule.

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 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).

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.

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.

This parameter directly affects the freedom of movement and ease of use: the farther the microphone can be taken from the connection point, the more convenient it is, especially when used in large spaces.

The presence of a flexible leg in the design of the microphone.

The flexible stem allows you to change the location of the capsule without moving the microphone from where it is installed. A rigid leg with a swivel mount can play a similar role, but the flexible design gives greater freedom of movement — with it the primer can be moved in almost any direction. This feature is useful primarily in computer and laptop models, as well as in conference devices : moving the capsule by just a few centimeters can significantly improve the quality of speech transmitted by the microphone, while moving the entire device is often undesirable, if not impossible.