A microphone is an electroacoustic transducer and works by converting vibrations caused by the acoustic pressure the sound waves apply to its capsule into electrical energy. Its main purpose is to convert audio signals into electrical impulses and to process sounds from any location or element.
What is a Microphone, and What are its Types?
There are many types of microphones used today including hand, pendant, piezoelectric, communication, and studio types. Handheld devices are often used for interviews such as interviews. Pendant-type devices were neck-mounted devices in the past, but over time, neck-clip types were also developed.
The piezoelectric type is divided into PZ or PZM and provides the best reception of sounds transmitted from hard surfaces such as tables. Devices used in the communication type capture sound in direct contact with the sound source and are often mounted on musical instruments.
The devices used in studio studies are the largest microphone type and contain various designs according to various applications. The only operating logic of all the devices in these categories is that sound waves are converted into electrical energy and also have different types of transducers.
Dynamic devices are also called moving coils and are considered to be the most durable professional devices. This type is widely preferred for journalistic work where various difficult conditions are common.
Their biggest advantage is that they do not need an external power source to operate and are particularly resistant to physical impacts.
In addition, another type may be preferred as a capacitor type, with a smaller size and excellent sensitivity, and best sound quality.
In such devices, a small coil works by generating a current from the movement of the membrane or diaphragm.
The main advantages should cost, robustness, easy to use, robust, and low output resistance. The disadvantages are a slightly uneven frequency and high sensitivity to shock and vibration.
They are often used for very loud instruments and outdoor shooting and can be connected with long cables.
The only difference between dynamic strip devices and coiled devices is that a metal tape is used instead of a coil. The main advantage of this type is its robustness and ability to operate at medium and low frequencies. The disadvantages are their weight and unevenness, and they are also not recommended for very loud instruments.
Also called capacitors or electric condenser microphones, these devices have a quality sound. It is handy and more portable due to its small size. Most capacitor devices are not as robust as dynamic ones.
Capacitor devices operate on the principle of an electrical capacitor. These are combined with an ultra-thin metal diaphragm, a flat piece of metal or ceramic. This means that a power supply provides an electrical charge between the two elements.
Sound waves hitting the diaphragm cause fluctuations in the electrical charge that must be amplified in the preamplifier, so the preamplifier is integrated into the body of the microphone.
Devices in this category require a preamplifier and need a power source such as a current or a battery. A capacitor is usually placed in the audio mixer to provide AC power to the microphone.
In such a power system, the cable transmits the signal received by the microphone to the console and transmits power from the console to the microphone preamplifier. It is better to use batteries as the power source for the preamplifier, but due to their lifetime, the batteries run out.
Also, if one of the microphones fails, the other is activated immediately. This dual microphone technique is known as dual redundancy. It is much more sensitive than strip devices and there are also different types used in dynamic and condenser television production.
Piezoelectric devices are pressurized and purely sound reflection devices that are used limitedly for certain effects. These microphones are far superior to other types.
Communication-based devices pick up sound while in physical contact with the source and are often mounted on musical instruments such as a piano’s soundboard, acoustic bass surface, or a violin bridge.
Contact or communication microphones do not interfere with any external interfering noise and sound reflections when colliding with nearby objects.
Like some devices, microphones also have a direction feature. These devices are divided into three categories as versatile, bidirectional, and unidirectional.
Omnidirectional devices are equally sensitive to sounds from any direction. Because of this feature, more than one person can be around the microphone, so they are widely used in video production.
It also removes unwanted noise while capturing audio from video editing.
Two-way devices are sensitive to pick up sounds coming from two directions. Although these types of devices are generally used in radio interviews and stereo systems, they are rarely used in television systems.
Unidirectional devices are basically sensitive to sounds coming from only one direction and this category is divided into four.
The cardioid uses a sensitivity pattern that resembles the shape of a heart and is sensitive to a wide range of sounds in front of the microphone but relatively insensitive to sounds behind the microphone.
Devices with this model are widely used in a studio because of the wide range of sensitivity. These devices can even record unwanted sounds, including reverberation from walls, when placed two or more meters away.
The supercardioid is considered to be more directional than the sensitive model of the cardioid, and when such a device is directed towards a sound source, it clears the interference of sounds outside the focus of perception.
They are widely used in the production of shotgun microphones and, thanks to their excellent directionality, they work very well at a distance of between two or five meters.
Devices known as hypercardioid and ultra-directional are an even more versatile model. Thanks to its narrow response angle feature, it effectively cleans out-of-range sounds and is precisely targeted to the sound source. This is why some high direction shotgun microphones are included in this category.
Parabolic devices have the highest directionality and differ in more useful as opposed to a particular type. The reflector forms the polar pattern in this system.
The parabolic reflector can be 1 to 3 feet in diameter, and due to its shape, all sounds recorded at a very narrow capture angle can be easily directed into the microphone. In addition, they can pick up sounds from a distance of 300 feet or more. It is often used in sports coverage, although it is not practical for general production work.