In the past, microphones were only paid attention to by singers and hosts. Now, many people who work as anchors also use microphones, so many brands of microphones are also made more civilian. The microphones look similar, but in practical applications, different types of microphones have very different effects in different environments. In general, microphones can be divided into 7 categories.
1. Dynamic microphone
In the microphone, the so-called "moving coil" refers to the wire coil closely connected to the diaphragm. According to the change of sound pressure, it continuously moves in the magnetic field to generate a current that changes in proportion to the amplitude of the sound wave, thereby converting the acoustic signal into electric signal. Since the dynamic microphone can use the coil to cut the magnetic field to generate current, the dynamic microphone does not need power supply, which is the biggest advantage of this type of microphone. The disadvantage of a dynamic microphone is that the diaphragm responds slowly to fast-changing sound waves due to the influence of the wire coil.
Dynamic microphones are usually used to record the sound from electric guitar speakers and vocal recordings, which seems to have become a kind of "tradition." Although there are already many condenser microphones designed specifically for recording live vocals, the unit price of condenser microphones is often higher, and people still prefer to use dynamic microphones to complete their work.
2. Large-diaphragm condenser microphone
In fact, there is no prescribed standard in the industry to distinguish the size of the large and small diaphragms. It is generally agreed that 12 mm or so is called the small diaphragm, and the size of 24 mm or larger is called the large diaphragm. Diaphragm. It should be noted that the size of the diaphragm is not reflected in the appearance of the microphone. Some microphones that look very large have a small diaphragm.
Large-diaphragm microphones are rarely used now. It appeared because the production level in the past was not high enough, and microphone manufacturers could not make the diaphragm as small as it is now. Large-diaphragm microphones can make your voice appear thick and warm, but because of its obvious directionality, it is not good for side sound reception.
Three, small diaphragm condenser microphone
The design of the condenser microphone is based on the principle of electrostatics. The diaphragm and the back plate of the microphone constitute a complete 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 For electrical signals.
Generally speaking, because the output of the capacitor unit is very weak, the capacitor microphone will have a built-in amplifier, and an external 48V phantom power supply or battery is required for power supply.
A small diaphragm of about 12 mm is very sensitive to the vibration of sound waves, so the larger the diaphragm, the lower the sensitivity to sound sources that are not directly facing the microphone. Therefore, if you want to achieve a more accurate sound reception, you need to choose a small-diaphragm condenser microphone.
Four, aluminum ribbon microphone
The ribbon microphone is actually a special dynamic microphone. It is different from the traditional dynamic microphone. It combines the diaphragm and the wire coil to form an aluminum ribbon. Due to the light and thin texture of the aluminum ribbon, the aluminum ribbon microphone is sensitive to sound waves. Almost comparable to condenser microphones.
Generally speaking, the sound of the ribbon microphone is relatively low, and it can record a slightly dim sound with clear details. In addition, this type of microphone is relatively fragile, and you can't even walk too fast while holding it, so as not to have too fast air passing through the microphone and cause the ribbon to misalign. The ribbon microphone does not need power supply, and the output is small, and generally needs to be used with a pre-amplifier.
Five, piezoelectric microphone
Piezoelectric microphones are also called "crystal microphones". The principle is to use the piezoelectric effect of certain materials, that is, the use of sound to cause material deformation to produce voltage changes.
Piezoelectric microphones mainly exist in the form of contact microphones, such as guitar pickups. The microphone directly picks up the physical vibration of the sound source instead of the sound wave vibration in the air. The advantage is that the sound of the instrument can be separated from other sounds, but the recorded sound lacks realism.
Six, electret microphone
An electret microphone is a special condenser microphone. Its material is a material that can permanently store these charges after adding charges. Using this principle, the electret material on the diaphragm or backplane provides capacitance The constant voltage required by the unit allows the microphone without power supply. But because it has an amplifier, it still needs phantom power or batteries when working.
Electret microphones are relatively low in cost and small in size, and are usually used in hand-held applications. Many of the most accurate microphones in the world are electret microphones.
Seven, vacuum tube microphone
Vacuum tube microphones appeared very early. At that time, since transistors had not yet been used on a large scale, the built-in amplifiers in condenser microphones were all based on vacuum tubes. The vacuum tube in this type of microphone is prone to produce a very pleasing and comfortable distortion effect, which is suitable for human voice recording.