The microphone is a very personal item for musicians, and many factors must be considered when choosing. In a wide variety of microphones, there is no theorem such as "a certain microphone is the best". Each type of microphone has its own unique properties and uses, and the sound quality produced is also different. Let’s take a look at 7 common microphones.
The meaning of "moving coil" is that the wire coil closely connected to the diaphragm moves continuously in the magnetic field according to the change of sound pressure, thereby generating a current that changes in proportion to the amplitude of the sound wave. In this way, the acoustic signal is converted into an electrical signal.
The coil of the dynamic microphone cuts the magnetic field to directly generate current, so the dynamic microphone does not need power supply. The advantage of a dynamic microphone is its simplicity and practicality. The disadvantage is that due to being "dragged" by the wire coil, the response speed of the diaphragm to fast-changing sound waves is not as fast as other types of microphones.
It is difficult for a dynamic microphone to pick up the high-frequency part of the wiper's high energy, but when picking up a strong kick or snare drum sound, the dynamic microphone can have a satisfying performance. Dynamic microphones are also often used to record the sound of electric guitar speakers.
Dynamic microphones are often used for vocal recording, which is largely a "traditional custom." Because the previous condenser microphones were bulky and fragile. But although condenser microphones designed specifically for live vocals abound, their more expensive average prices tend to make people more inclined to choose dynamic microphones that can also do their job well.
Small-diaphragm condenser microphone
The condenser microphone is designed based on the principle of electrostatics. The diaphragm and the back plate constitute a capacitor unit. The vibration of the diaphragm with the sound wave causes the potential difference between it and the back plate to change, thereby converting the acoustic signal into an electrical signal. Condenser microphones generally have built-in amplifiers because the output of the condenser unit is very weak. Condenser microphones require an external 48 V phantom power supply or battery.
The significance of choosing a small-diaphragm condenser microphone is that those small diaphragms with a diameter of about 12 mm are very sensitive to the vibration of sound waves. The larger the diaphragm is, the less sensitive it is to the sound that is not facing the microphone, and the more obvious the sound staining caused by resonance.
If you want extremely accurate sound effects, then a small-diaphragm condenser microphone is the best choice. It should be noted that a more precise sound is not necessarily a more satisfying sound. Sometimes a precise sound does not sound so dynamic and powerful. But if you want to record the sounds of nature completely and truly, a small-diaphragm condenser microphone should be your choice.
Large-diaphragm condenser microphone
In the past, microphone manufacturers could not make the diaphragm as exquisite as it is now. All condenser microphones at that time should be called "large-diaphragm condenser microphones." Of course, there is no dividing line to define what is a "large diaphragm" and what is a "small diaphragm". As mentioned earlier, a size of about 12 mm can be called a "small diaphragm", and a size of 24 mm or more can be counted as a "large diaphragm". When buying a microphone, we will find that some microphones that look very large have a surprisingly small diaphragm inside, so the size of the diaphragm is a microphone parameter that requires our special attention.
The advantage of a large-diaphragm condenser microphone is that it can give you the kind of sound that the recording studio particularly admires-not the most natural sound, but the sound is thick and warm, and it feels very comfortable no matter what sound is recorded.
The disadvantage is that the higher the frequency of the sound, the more obvious the directivity of the large-diaphragm condenser microphone. If you are facing the microphone, this is not a problem, but if you use two microphones for stereo reception, the sound from the side may not be ideal.
Vacuum tube microphone
The design and manufacture of this type of microphone can be traced back to the early days of condenser microphones. At that time, because transistors had not yet been widely used, the built-in amplifiers of condenser microphones were all vacuum tubes. Although some vacuum tube microphones used to have small diaphragms, most of the vacuum tube microphones we see now have large diaphragms.
The advantage of the vacuum tube microphone is that the vacuum tube amplifier is prone to produce a very pleasant and comfortable distortion effect, that is, "warm sound". For vocals, this kind of warm distortion is often used as a panacea.
Unlike other types of microphones, vacuum tube microphones have become very popular since the age of vacuum tubes have long passed, and their prices are often high.
The ribbon microphone is a special dynamic microphone. The diaphragm of a traditional dynamic microphone is tightly connected with a wire coil, while an aluminum ribbon microphone combines the diaphragm and the wire coil to form an aluminum ribbon (or metal ribbon). Because the aluminum ribbon is very thin and light, the sensitivity of the aluminum ribbon microphone to sound waves can be comparable to that of a condenser microphone, but the sound of the general aluminum ribbon microphone is relatively dark.
The ribbon microphone can record clear but slightly dim sound. This makes them often used artistically in recording studios.
Ribbon microphones are generally very fragile, so fragile that some brands' manuals will remind users: When holding the ribbon microphone to receive the sound, walk slowly to prevent the air from passing through the microphone too fast and causing the ribbon to displace.
Like dynamic microphones, most ribbon microphones do not require external power supply (except for some built-in amplifiers). However, the output of ribbon microphones is generally relatively small, so it is better to use with a pre-amplifier.
The electret microphone is a special condenser microphone. We already know that the principle of a condenser microphone is that the amount of polarized charge on the capacitor changes, thereby generating electrical signals at both ends of the capacitor to achieve acoustic-electrical signal conversion.
The electret material is a material that can permanently retain these charges after adding charges. Using this principle, the electret material on the diaphragm or the backplane provides the constant voltage required by the capacitor unit, which can save the power supply of the microphone. However, the work of the microphone built-in amplifier still requires battery or phantom power. It should be noted that battery-based electret microphones are less sensitive than phantom-powered ones, and have a weaker ability to handle the maximum sound pressure.
Electret microphones are widely used in handheld devices because of their low cost and miniaturization. An electret microphone with an internal integrated FET preamplifier can provide high performance. Many of the most accurate microphones in the world today are electret microphones.
Piezoelectric microphones are also called crystal microphones, and their principle is to use the piezoelectric effect of certain materials-that is, sound causes the deformation of the material to produce a voltage change.
Piezoelectric microphones are now mainly in the form of contact microphones. A typical example is a guitar pickup. The piezoelectric microphone directly picks up the physical vibration of the sound source instead of the sound wave vibration in the air. The advantage is to isolate the sound of the instrument from other sounds. However, the sound picked up in this way will not be particularly real, so the application of piezoelectric microphones is more limited.
to sum up
This is the 7 types of microphones classified according to their working principles. Being able to understand their basic working principles and recognize their unique sounds is one of the necessary skills for every music producer.