TYPE AND APPLICATIONS
• 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
• 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
• 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
• 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
• 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
• 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.