Comparison AKG P120 vs Rode NT-USB

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.

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.

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.

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.

— Wireless connection. This feature is indicated for the so-called radio microphones — models in which the signal is transmitted wirelessly. Note that a radio microphone kit usually involves a receiver that is connected to an amplifier (or other sound processing device) in a classic wired way (see "Connection connectors"). However, the microphone itself is connected to the receiver via a radio channel.

— Stereo recording. The ability to use a microphone to record sound in stereo format. This format assumes the presence of two channels, and for each of them the sound must be recorded separately; but the technical support of such a recording in different cases may vary. The most popular option is bi-directional microphones. However, in addition to this, this category includes paired sets for which the stereo recording function is directly claimed.

— LPF (Roll-off). The presence of a low-pass filter in the design of the microphone (Roll-off is an alternative name for this function). This feature allows you to reduce the level of low frequencies in the signal produced by the microphone. This need may be due to two factors. Firstly, many extraneous noises are the sound of the wind, knocks on the device case, the surrounding background, etc. — are presented at low frequencies; by suppressing this range, you can significantly reduce the level of extraneous so...unds “heard” through the microphone. Secondly, the LPF is useful for working with the so-called "proximity effect". This effect consists in the fact that when approaching the sound source, many models tend to increase the volume of the bass sound, and when removed, on the contrary, they fail the “bass”. By turning on Roll-off when approaching the sound source and turning it off when moving away, this effect can be smoothed out to a certain extent. For a number of technical reasons, this function is mainly used in condenser and electret microphones (see "Type"). Note that in advanced models, the low-pass filter can be made customizable and supplemented with an auxiliary ultra-low pass filter.

— Attenuator. The presence of an attenuator in the design of the microphone — a device that gradually attenuates the signal level at the output (a kind of opposite to an amplifier). This feature is useful when working with loud sound: by lowering the signal level, you can avoid overloading the system.

— Sensitivity adjustment. The presence of its own sensitivity control in the design of the microphone. This function allows you to adjust the signal level without using the controls in other components of the audio system — for example, to change the volume on the fly; this is quite convenient, since the microphone is usually at hand, and settings can be changed very quickly and without much hassle.

— Headphone volume adjustment. A separate knob for adjusting the volume of connected headphones (see "Headphone output"). Depending on the model, it can be placed both on the microphone itself and on the receiver for wireless connection. Anyway, this feature makes adjusting the volume more convenient: the control is at hand and the user does not need to reach for other devices or delve into the software settings.

— Mute the microphone. The presence of its own switch in the design of the microphone. In some use cases, it is not uncommon for situations where the microphone has to be constantly turned on and off. For example, during a concert, the number of performers may change, and it is better to turn off unused microphones; when communicating via Skype through a computer, sometimes you have to be distracted by conversations with others that the “computer” interlocutor does not need to hear, etc. Usually, muting the microphone is possible through the settings or control panel of the device to which it is connected; however, using your own switch is usually easier and faster, especially if you have to mute / unmute the sound frequently.

— Built-in memory. The presence of built-in data storage in the microphone eliminates the need to use external storage media to record sound. On-board storage is found in some models of advanced “lavaliers”, microphones for video cameras and voice recorders - i.e. in portable solutions with a view to comfortable work in the field.

— Switching DN. DN in this case means “directional pattern”, however, this function may mean switching not only between options for a unidirectional microphone (see “Directional Pattern”), but also between one-, two- and omnidirectional operation format (see “Directionality”). microphone"). Therefore, specific switching features and available options should be clarified for each model separately.

Types of connectors provided in the design of the microphone.

Most often, in this paragraph we are talking about the type of connector designed to connect the microphone itself to external audio equipment. Of these interfaces, the most popular nowadays are analogue XLR(including a smaller version of mini-XLR), Jack 6.35 and mini-Jack 3.5 mm, as well as digital USB A, USB-C and Lightning. Also, individual microphones provide their own headphone jack(sometimes Microdot). Here is a more detailed description of each option:

— XLR. A characteristic round plug of a rather large size, usually with an external casing. In microphones, 3-pin XLR plugs are most common, one such plug allows you to transmit one channel of sound; other options are possible — for example, a 4- or even 5-pin connector in a model that supports stereo recording (see "Functions and Capabilities"). Anyway, the main advantage of XLR is the ability to work with a balanced connection. With this connection, most of the interference induced on the cable is extinguished "by itself", without the need for additional filters; this allows fairly long wires to be used without sacrificing sound quali...ty. In addition, the XLR connectors provide a tight connection, further improving noise immunity; and for additional security, sockets and plugs of this type are often equipped with locks. The main disadvantage of XLR is its large size; therefore, the main scope of its application remains professional models, where the mentioned advantages far outweigh the disadvantages.

— mini-XLR. A smaller version of the XLR interface described above; has the same technical features and differs only in smaller sizes. The latter makes the mini-XLR more suitable for applications where compactness is important. At the same time, such connectors do not yet have official standardization, and therefore are quite rare.

— mini-Jack 3.5 mm. One of the most popular modern audio connectors. In microphones, however, it is much less common than the same XLR — mainly in compact models, as well as entry-level and inexpensive mid-range solutions. This is due to the fact that the mini-Jack is small in size, but noticeably inferior to XLR in terms of quality and connection reliability, which is why it is poorly suited for professional tasks. It is also worth considering that in modern microphones you can find different versions of the 3.5 mm jack:

• mini-Jack 3.5mm TS. A two-pin connector that allows you to transmit only 1 channel of sound (mono). It is found in fairly advanced microphones, and 3.5 mm jacks of this format are used in basic audio equipment of the appropriate level and specialized devices (like transmitters for lavalier microphones).
• mini-Jack 3.5 mm TRS. Three-pin, the most common type of mini-jack connector. Technically, it can be used for balanced connection of one audio channel (see “XLR” above), but in fact it is more often used either for compatibility reasons (so that the microphone can work normally with three- and four-pin jacks on laptops, phones, etc.), or to transmit a stereo signal (in models with the appropriate functionality — see "Functions and Capabilities").
• mini-Jack 3.5mm TRRS. Four-pin mini-jack plug. It is used mainly in models for smartphones / tablets, camcorders and other equipment — such equipment is often equipped with sockets for exactly 4 connectors, and for optimal compatibility, the same number of contacts is also provided on the microphone. Stereo audio can be transmitted through such an interface, but this capability is not necessarily supported.

Ideally, a microphone with a mini-jack should be connected to a connector that has the same number of pins — otherwise, normal operation is not guaranteed (although exceptions are possible).

— Jack (6.35 mm). Full-size Jack; has almost twice the diameter of the 3.5 mm mini-Jack described above. Poorly suitable for portable equipment, but it provides a fairly tight and reliable connection — although it is somewhat inferior to XLR in this parameter; can also be used for balanced connection (see "XLR"), but in this format it is used relatively rarely. Note that in some microphones, the 6.35 mm interface is provided not as a full-fledged plug, but as an adapter for a 3.5 mm mini-jack installed on the wire. The Jack connector can also have a different number of pins, but in this regard it is not as diverse as the mini-jack: the classic 3 pins (TRS) are the most common, and the 4 pin format (TRRS) is practically never found.

— TA4F. A specialized connector used in audio equipment, and mainly in microphones. Also, this term can mean a connector of a similar design TA3F (with 3 contacts).
The TA4F is fairly small, making it suitable for compact head and lavalier microphones. And thanks to the presence of 4 pins, you can also connect phantom power for condenser microphones through it (however, the use of TA4F is not limited to this type of microphone). Note that this connector is considered professional and is found mainly in the technique of the corresponding level.

— USB. The USB interface is mainly used in computer technology — to connect various peripheral devices. At the same time, among models for PCs and laptops (see "Intended use"), this option is much less common than the mini-Jack 3.5 mm described above, and most microphones with USB are studio ones. This is due to the fact that the signal is transmitted via USB in digital format, which is very convenient when recording to a computer for further processing and mixing (but for voice communication it is more convenient to use a regular microphone input). However, there are other types of microphones with this interface.

— Lightning. A proprietary connector used exclusively in Apple portable devices — iPhone smartphones, iPad tablets and iPod touch players. Accordingly, this connection option is found exclusively in microphones for Apple smartphones, moreover, specially designed for this technique.

— microdot. Balanced jack for coaxial connection to musical instruments and other acoustic/audio equipment. The microDot connector is characterized by the presence of a thread, which ensures a high reliability of the connection. The microDot connection is commonly found in compact microphones mounted on a musical instrument.

— Corporate outlet. This category includes all interfaces not related to those described above. These can be not only their own connectors used by a certain company, but also some standard connection types that are not widely used and are found in specialized technology. However, anyway, when buying such a microphone, you should separately make sure that it is compatible with the device with which you plan to use it.

— Headphone output. Separate headphone output. Most often it looks like a standard mini-Jack 3.5 mm jack — it is this interface that is used in most modern "ears", which gives the user a wide choice. In addition, such an output can be combined with its own volume control.

The remaining features of both the connector itself and its application depend mainly on the type of microphone (see "Microphone"). So, lavalier models, when headphones are connected, turn into headsets; when used in karaoke, headphones make it possible to listen to music better, and when used in a studio, they also allow you to hear your own voice, controlling what is being recorded. Also note that in radio systems (see above), such an output is usually located on the receiver.

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.