How to read the Microphone Specifications?What do these values mean?

A microphone is necessary for playing music, and there are so many microphones, how do you choose? How to read the Microphone Specifications?What do these values mean? And below is the specification sheet for Sinbosen's wireless handheld microphone SR314S.Maybe you still don't understand now,Waiting for you to read this article, and then came back to see this table may be suddenly enlightened!

1. Type

Common microphones can be divided into two types according to the way they convert sound into electrical energy:

(1)Dynamic: It is more durable, not easily affected by temperature and humidity, and can withstand loud sounds without distortion.

(2)Condenser or pressure gradient transducer: The sound is more detailed, the response is sensitive, and the bandwidth is wide. It needs to be powered by a battery or phantom power (+20~48V), and it can be made into a very small microphone.

2. Frequency Response

The volume of the microphone's response to the sound of different frequency bands at a certain distance and with a fixed volume. In short, it is the response state of this microphone to the frequency. Microphones with a wide, flat frequency response contribute to natural, clear sound. The lower the fluctuation value, the better the microphone sound quality. In general, the frequency response parameters that the microphone should have: 80Hz-15kHz, bass instruments: above 40Hz, and the human hearing limit: 20Hz-20kHz, so any frequency response parameters that exceed the human hearing limit are invalid.

3. Polar Pattern

Refers to the microphone's response to sounds from different directions. There are three types:

(1) omnidirectional: It can receive sounds from all directions, and is mostly used to receive the sound of the entire environment. It is less sensitive to the spray microphone and has less proximity effect.

(2) unidirectional: which can be divided into cardioid, supercardioid, hypercardioid, and shotgun. Most of the above directional microphones receive the sound from the front, and are not sensitive to the sound from the side. They are suitable for picking up specific main sound sources (such as human voice or musical instruments), reducing the sound received outside the front of the microphone, reducing Give back opportunities. This type of microphone is directional by relying on the sound hole on the side of the pickup head. Do not grab the sound hole on the side when using it. When it is very close to the sound source, a proximity effect will occur, and the low frequency will be prominent, but the advantage is that this feature can be used to increase the soundness of the sound.

(3) Bidirectional orfigure-8: It can receive the sound in front of and behind the microphone, and is less sensitive to the sound from the side.

4. Sensitivity: the degree of response to the source sound

The unit of sensitivity can be "mV/Pa" or "mV/10μbars", where Pa and μbars are both units of pressure, 10μbars = 1Pa. Sensitivity expressed in this way, the larger the value, the higher the sensitivity. For example, the sensitivity of 27.5mV/Pa is greater than that of 6.5mV/10μbars. Some companies express sensitivity in the form of "-dB", and the reference standard is also 94dB or 74dB. In this case, the smaller the number after the minus sign, the higher the sensitivity. For example, A microphone produces -58dBV, B microphone is -43dBV, B>A, so B microphone is more sensitive than A, and B may be able to record small sounds that A cannot record. The choice of high-sensitivity or low-sensitivity microphone depends on the conditions you use. If the sound source is far away from the microphone, use a microphone with high sensitivity; if the sound source is close to the microphone, use a microphone with low sensitivity. The former can ensure the sensitivity of picking up sound signals, and the latter can effectively reduce ambient noise. For example, when used for karaoke singing, the distance between the microphone and the mouth is very close, so the requirements for sensitivity are not high.

5. Self-Noise: refers to the noise value of the microphone itself

The smaller the dBA of self-noise, the better. So if both mics are in dBA units, the comparison is pretty obvious. "For the self-noise of condenser microphones, the current large-diaphragm products can generally be as low as 5dBA." The self-noise of the small-diaphragm microphone will be larger, between 12dBA and 18dBA, and the smaller diaphragm can reach 22dBA to 27dBA.  Therefore, the environment in which the microphone is used is very important. Once the self-noise exceeds 20dBA, there will be problems in a relatively quiet environment such as a traditional recording studio. However,below 25dBA is considered a good value.

6. Signal to Noise Ratio

Refers to the volume difference between a signal and its own noise. A larger value means that the signal is much louder than its own noise. When the signal is relatively large, the noise generated by the microphone itself can be ignored, and the ear cannot hear the noise of the microphone itself. S/N Ratio greater than 69dB is a good value.The larger the signal-to-noise ratio, the smaller the noise and the higher the quality of the sound output.

7. Impedance

The impedance of the microphone is 150-600ohms for low impedance, 1000-4000ohms for medium impedance, and 25kilohms for high impedance. Try to use a low-impedance microphone. A high-impedance microphone is prone to frequency attenuation and current sound. The lower the impedance, the higher the microphone sensitivity. "For any given microphone parameter table, one can find a value describing the output impedance. The output impedance of any professional microphone is 'smaller', somewhere in the range of 50Ω to 600Ω. And most of these are located in Between 150Ω and 250Ω.”

8. Maximum SPL : Maximum withstand sound pressure

Refers to the maximum sound pressure value that the microphone can receive without distortion. The maximum input sound pressure level of the microphone is above 130dB, which is already a very good microphone.

9. Polarity : Polarity

Refers to the polarity of the output after the sound is converted into an electronic signal. Usually professional microphones will use XLR, which is commonly known as the signal connector of the Cannon head, which has three pins for welding wire. (When purchasing equipment, don't forget to pay attention to whether the specifications of the equipment are interoperable with other equipment in the system.)

10.Power Requirements: Power requirements

This refers to the external power supply requirements of the microphone. The most common is the 48V phantom power required by condenser microphones, which is usually realized by connecting an XLR cable to a mic preamp. Some microphones also have an internal battery in case phantom power is unavailable. Power requirements are generally indicated by an acceptable voltage range.

11.Dynamic Range

Dynamic range refers to the SPL (sound pressure level) range between the microphone's noise floor (or self-noise) and the maximum sound pressure level. Obviously, the larger this parameter is, the better.

12.Off-Axis Frequency Response

This graph shows the performance of a specific frequency at each angle currently pointed, and its focus is to graphically express the change of a specific frequency. If a mic performs better off-axis, it will be less affected by other sounds in the space, so the final mix will be clearer, neither muddy nor heady, and avoid negative sound pollution Effect.

13. Connector : Connector

Refers to what kind of connector is used for the signal output of the microphone. The XLR connector is the most common type of professional microphones, because XLR is a balanced wire and can be used for signal transmission over a long distance without induced noise. But some special Contacts (contact microphones, also called transducer or piezoelectric microphones) may have simpler 6.5 or 3.5 connectors.

Of course, the quality of the specifications does not necessarily mean that the microphone is good or not, and the sound is praised or not. It's worth emphasizing here: the microphone is only a matter of applicability or inapplicability. It is not that a top-level microphone with good specifications or an expensive price will be good for recording any sound! If you use the U87 commonly used in recording studios to sing in a pub, you may receive a bunch of miscellaneous ambient sounds, which will destroy the effect of your PA system!