TYPE AND APPLICATIONS OF MICROPHONESJil sheth

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• Microphones are ubiquitous devices that have applications in many facets of life, from computers to cell phones to music. Given the wide range of microphones available on the market these days, it can be helpful to understand the differences between all the options out there. Microphones can also often be marketed based on certain technical specs that many consumers may not be familiar with.

• Sometimes referred to as mics, microphones vary from small integrated elements that work from within larger pieces of technology to free-standing devices that can be leveraged in recording, performing, and mixing scenarios. They can facilitate communication online via a computer or help a karaoke fan perform. All these various options can be found to an extent at specialty computer and music shops, but by and large are found to the largest extent via online auction sites such as eBay.

• How Microphones Work

• Microphones are transducers are devices that take one form of input energy and transform it into a different output energy. Microphones take the acoustical signal of a vocal performance and transform it into an electrical signal that can then be filtered through effects, processed on a soundboard, projected via an amplifier, or even transmitted as a radio or digital signal.

• Microphones do this by leveraging a transducer element usually referred to as either a "capsule" or an "element." Other important parts of a microphone include the housing that encases the internal parts and filters the input acoustic signal, and a method for transmitting the output signal to an external device, which can be anything from an electronic circuit to a radio transmitter.

• The Different Transducer Principles of Microphones

• The way in which a microphone transforms an input signal from the acoustic to the electric is known as its transducer principle. The transducer principle of a microphone can define it on the market and is often referenced as a selling point, so it is important for consumers interested in purchasing a microphone to be familiar with the most popular transducer principles.

• Electromagnetic Induction Microphones

• Microphones that use electromagnetic induction to transform an input signal are commonly called dynamic microphones. They are widely used as vocal microphones on stage, due to the fact that they can achieve a very high gain before inducing feedback.

• Dynamic microphones feature an induction coil placed on a magnet that is attached to the diaphragm of the microphone. When the acoustic signal enters the microphone, the diaphragm vibrates, stimulating the induction coil and producing an electrical current. Microphones that leverage electromagnetic induction often feature a single membrane, but some more advanced microphones can feature multiple dynamic membranes.

• Ribbon Microphones

• Ribbon microphones are very similar to magnetic induction units in that they leverage a magnetic field to transform an acoustic signal into an electric one. Instead of using an induction coil, however, a ribbon microphone uses a thin ribbon of metal as the sensor in the magnetic field.

• The most well-known version of the ribbon microphone is the one used in radio production in the 1930s and 1940s. These older ribbon microphones are still collected today as vintage items, thanks to their iconic look and high quality performance. Modern versions of the ribbon microphone are also in production and leverage nanomaterials that make the modern versions much less delicate than the older iterations.

• Condenser Microphones

• A condenser microphone transforms an acoustic signal into an electric one by leveraging a capacitor, a two terminal electrical component. The diaphragm of the microphone is actually used as one element of this capacitor; when the acoustical signal causes the diaphragm to move, the distance between it and the other half of the capacitor is affected, creating the electrical output signal.

• Condenser technology is widely used in microphones today and can be found in everything from a karaoke microphone to recording studio microphones.

• Piezoelectric Microphones

• Piezoelectric microphones feature sensitive crystals that respond to the physical vibration of the acoustic signal coming into the microphone and create the electrical output. While this technology was once used in widely in tape recorders, it is most commonly used today in pickup devices for acoustic instruments.

• Fiber Optic Microphones

• Fiber optic microphones use the changes in light intensity produced by laser technology to capture the acoustic signal and transform it into an electric one. Unlike the other transduction types, a fiber optic microphone creates no disturbance in an electrical or magnetic field, making it a good microphone to leverage in magnetically or electrically sensitive environments, such as within an MRI machine.

• Microphone Directivity

• The design of a microphone can affect its directivity, or the direction from which a microphone can optimally receive an acoustic signal. This can also be an important selling point for a microphone and is a crucial factor to consider when purchasing one of these devices.

• In general, microphones can be divided into omnidirectional and unidirectional devices. An omnidirectional device (sometimes referred to as a nondirectional mic) can absorb from any input direction in theory. In reality, the microphone’s own physical design makes this absolute principle inapplicable in real life.

• Different Types of Unidirectional Microphones

• Unidirectional microphones can leverage several different polar patterns or shapes that indicate from which direction they will best receive an acoustic signal. Purchasers should consider these differences when looking through unidirectional microphones and try to match a microphone’s polar pattern to the application for which it will be used.

• Cardioid Microphones

• Cardioid microphones are unidirectional mics that absorb an acoustical signal in a figure-8 pattern. This sound pattern makes these microphones good vocal microphones, as they can absorb the dynamic range of a vocal performance while not capturing signals from other directions.

• Bi-Directional Microphones

• Bi-Directional microphones receive a balanced signal from both the front and back of the microphonic element. The most classic examples of a bi-directional mic are the ribbon microphones used in radio during the 1930s and 1940s.

• Shotgun Microphones

• A shotgun microphone is the most focused of the unidirectional mics. A shotgun is highly directional and is best used to capture a very small sound range in a concentrated space.

• The Diaphragm Size on Microphones

• The diaphragm size on a microphone can sometimes factor into a microphone purchase, especially when it comes to condenser mics that are being purchased for a high-fidelity, studio environment. The size of a microphone’s diaphragm can affect how well it can address certain instruments or frequencies and should factor into a decision when a studio microphone is being considered.

• Small Diaphragm Microphones

• Small diaphragm microphones are a strong choice for "miking" an instrument, such as an acoustic guitar that has extended overtones. These microphones also function well as drum microphones, since they can deal well with the sharp attack of certain drums, especially a hi-hat. These microphones are also easy to position thanks to their lightweight and compact design.

• Medium Diaphragm Microphones

• Medium diaphragm microphones are hybrids that attempt to balance the assets of large and small diaphragm microphones. These microphones can be good at addressing overtones and sharp transients while still retaining some of the warmth of a larger diaphragm microphone.

Large Diaphragm Microphones

Large diaphragm mics are a staple of a studio environment, thanks to their ability to aptly

address almost any type of performance. They can leverage multiple pickup patterns, in

some cases, and usually imbue a performance with a warm tone. Some versions of large

diaphragm microphones are designed for more limited applications, such as recording kick

drums or toms in a drum kit, but by and large, these are multi-dimensional microphones.

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