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Microphones
How To Choose Wired & Wireless Microphones
 
 

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How microphones work?
What are the common types of microphones?
How to choose a microphone that works for you!


1. How do microphones work?

2. What makes microphones different from each other?

3. How to choose a microphone that works for you!




How Microphones Work

Microphones are components in virtually all audio systems.

MicrophonesThus, you'll hear about studio microphones for recording, PA microphones for live sound, boom microphones for broadcast or film shoots, instrument microphones which attach directly to guitars or horns, boundary microphones for conference systems, lapel mics for seminars and business meetings, and even headset microphones for telephone call centers. The reason for this diversity is that while all microphones perform the same basic function, they are adapted to a wide variety of different environments and uses.

That said, all microphones have one thing in common: microphones convert a sound wave into an electrical signal in which the voltage and current are proportional to the original sound.

To perform this task microphones use a thin membrane, known as a diaphragm, which mimics the function of the human ear.

 
To perform this task microphones use a thin membrane, known as a diaphragm, which mimics the function of the human ear.

When sound waves strike a microphone's diaphragm, they cause it to move within an electro-magnetic field, which, in turn, creates a variance in an electrical current. This signal is then transmitted to output devices, which reproduce the original sound wave and reinforce it. Typical output devices for microphones are power amplifiers, sound mixers, PA systems and audio recorders.

The internal configurations of microphones used for 99% of all audio systems have one of three basic designs, which are often used to organize microphones into distinct categories. These three categories are dynamic microphones, condenser microphones, and ribbon microphones.

MicrophonesThe link between the microphone's diaphragm and the output device can be either wired or wireless. Wired microphones are physically connected by a cable to the output device. Wireless microphones, which are more portable, must come with both a transmitter (either FM or InfraRed) and a compatible receiver.

Finally, to fully understand how microphones work, and the differences among them, it's important to consider the way different microphones gather sound from the ambient environment. Microphones can be classified by three types of pickup patterns: unidirectional or cardioid, bidirectional or figure 8, omnidirectional or boundary and switchable.

Each of these features has its own strengths and weaknesses.

Choosing among alternative configurations - say a wired dynamic cardioid microphone, a wireless ribbon omnidirectional microphone or a wireless condenser unidirectional microphone - is the key to making your audio system perform the way you want.

To simplify this kind of choice the staff of AudioLinks will be glad to discuss your needs and options.

Just fill-out our convenient self-help microphone questionnaire to get some useful suggestions.

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Types of Microphones

Audio engineers and sound technicians classify microphones using the following criteria:

•  The internal configuration of microphones including dynamic, condenser and ribbon diaphragms:

Dynamic Microphones
Dynamic Microphones In dynamic microphones a physical cone acts like a lens to concentrate the incoming sound waves.


Ribbon  Microphones
Ribbon Microphones Ribbon microphones consist of a thin strip of metallic foil suspended in front of a magnetic plate.


Condenser Microphones
Condenser Microphones Rather than a vibrating wire coil, condenser microphones have a thin diaphragm and solid back plate which make up an electronic component known as a capacitor.


•  The external configuration of microphones including wired or wireless signal transmission:

Wired Microphones
Wired Microphones Traditionally, microphones - like Model T Fords - came in any external configuration you wanted, so long as it was wired.


Handheld wireless microphones
Handheld Wireless Microphones are literally held in the hand of a presenter or a vocalist. In this way the microphones can be used as a prop in a performance.


Handsfree Wireless Microphones
Handsfree Wireless Microphones come in three popular configurations, lapel (or lavaliere) wireless microphones, collar wireless microphones and headband wireless microphones.


•  The pick-up pattern of microphones including unidirectional, bidirectional and omnidirectional:

 Unidirectional Microphones
Unidirectional or cardioid pickup patterns are most sensitive to sound produced on the front side of the microphone capsule. Super-cardioid pickup patterns have a greater sensitivity than cardioid pickup patterns.


Bidirectional Microphones
Bidirectional or figure 8 pickup patterns are sensitive to signals emanating from the front and back sides of the microphone capsule while rejecting sounds from the left and right sides of the microphone capsule.


Omnidirectional Microphones
Omnidirectional or boundary pickup patterns are sensitive to sound from all directions of the microphone capsule.



Switchable Pickup Pattern Microphones
Switchable pickup pattern microphones are hybrid microphones that can be switched from one pickup pattern to another for all-in-one flexibility in different environments.


TYPES OF MICROPHONES - THE INTERNAL CONFIGURATION OF MICROPHONES - DYNAMIC, RIBBON & CONDENSER MICROPHONES

Dynamic Microphones

Dynamic Microphones

In dynamic microphones a physical cone acts like a lens to concentrate the incoming sound waves. The concentrated energy of these sound waves moves the cone and its attached coil of wire back and forth inside a magnetic field. The magnetic field induces electricity to flow through the wire to produce an electrical signal which is the microphone's output.

The electrical signal is analogous to the original sound wave: the voltage and current are proportional to the original sound.

Dynamic microphones are well known for their versatility and their durability, but are not the best choice for reproducing high and low frequencies; dynamic microphones require significant energy to move the coil of wire and therefore lose definition at the extremes.

An example of a dynamic microphone is the Shure SM58 shown below:


Shure SM58 Dynamic Vocal Microphones

Shure SM58 Dynamic Vocal Microphones

 
Shure SM58 dynamic microphones became an instant classic when they were introduced more than 40 years ago, and remain so to this day - proving the old adage "If it ain't broke, don't fix it." These versatile, multi-purpose microphones are excellent at rejecting off-axis signals, while maintaining uniform frequency response. They're world renowned for noise Buy Nowreduction, brightened midrange and bass roll off. The SM58 is just one of the many Shure microphones famous for balancing low cost, amazing ruggedness and high quality sound. Learn MORE >>  


Ribbon Microphones

Ribbon Microphones

Ribbon microphones consist of a thin strip of metallic foil suspended in front of a magnetic plate. Sound waves cause the foil to vibrate, producing fluctuations in the electrical current, creating the audio signal.

This extremely sensitive configuration picks up a wide range of frequencies and produces an extraordinarily rich representation of the original sound. The trade off for this sensitivity is the delicacy of the mechanism. These ribbon microphones are also sensitive to physical impacts and therefore are not considered portable and can be easily damaged by power overdrive.

An example of a ribbon microphone is the Nady RSM-3 shown below:


Nady RSM 2 Gold Ribbon Microphones

Nady RSM 2 Gold Ribbon Microphones

 
Nady RSM-2 microphones offer unparalleled vintage ribbon (velocity) microphone sound and performance at an affordable price. These mics feature versatile physical and acoustic design for numerous vocal and instrument recording and live sound uses. Their compact housing makes for easy, unobtrusive microphone placement almost anywhere. The low-tension two inch long, two micron thick aluminum ribbon design delivers classic ribbon audio reproduction with smooth, uniform natural sound, fast accurate transient response, ultra-high 165 dB SPL capability, unmatched transient response and overall stunning realism. Learn MORE >>  

Condenser Microphones

Condenser Microphones

Rather than a vibrating wire coil, condenser microphones have a thin diaphragm and solid back plate which make up an electronic component known as a capacitor. As the diaphragm vibrates, the distance from the back plate to the diaphragm varies accordingly. This is known as fluctuating capacitance. It's the fluctuation that produces an electrical current, resulting in the signal output.

Condenser microphones are used for a variety of applications, making them an optimal compromise between the sound reproduction of ribbon microphones and the durability of dynamic microphones.

As a result of the widespread application of condenser microphones, they have evolved into a number of subcategories including electret condenser, cardioid condenser and even dynamic condenser microphones. These specialized microphones represent the largest single category of microphones currently in use and will be discussed in a separate article at a later date.

An example of a condenser microphone is the Sennheiser e865S shown below:


Sennheiser Condenser Microphones

Sennheiser Condenser Microphones

 
Sennheiser e865S condenser microphones are designed to excel in the most demanding and critical situations. The end result is highly accurate sound reproduction and amazing clarity. Qualities that come in handy when you're trying to cut through competing ambient sounds.Buy Now With a frequency range of 40 - 20,000 Hz, these solidly built microphones get the job done gig after gig. That's why Sennheiser confidently stands behind this model by offering a 10 year warranty. Learn MORE >>
 


Wired Microphones

TYPES OF MICROPHONES - THE EXTERNAL CONFIGURATION OF MICROPHONES - WIRED & WIRELESS MICROPHONES

The body style of individual microphones not only reflects design preference, but also depends on function.

In this section we will focus on that most basic of external features of microphones: the wired or wireless connection between the microphone and its output device.

Wired Microphones

Traditionally, microphones - like Model T Fords - came in any external configuration you wanted, so long as it was wired.

The connection between the diaphragm and the sound system was a hard wired cable that carried the electrical current to the speakers. For instance, the Anchor Audio Mic90 is a good example of the classic wired microphone.


Anchor Audio  Wired Microphones

Anchor Audio Wired Handheld Microphones

 
Anchor Audio MIC 90 handheld microphones are excellent examples of classic wired microphones. Designed to be versatile, Buy Now Anchor Audio MIC 90 wired microphones are highly portable and extremely durable. They come with a 6 year manufacturer's limited warranty. These microphones include a fitted carrying case, a swivel adapter and a 20 foot XLR cable which is plugged directly into the PA system.
 

What's radically different today, is that you have a number of sophisticated choices for wireless microphones.

Wireless Microphones

The main advantage of wireless microphones as compared to wired microphones is freedom of movement. With wireless microphones a vocalist or presenter has much greater flexibility to move around a stage or among an audience. The biggest disadvantage is price, as wireless microphones in general are more expensive.

Characteristically, wireless microphone systems require a wireless transmitter, and a wireless receiver.

The wireless transmitter is either built into the microphone itself (as in handheld microphones), or is connected by a short cable to a body pack transmitter (as in handsfree microphones). All wireless transmitters require a battery (typically 9-volt or AA batteries) and broadcast through an internal or external antenna.

The wireless receiver is tuned to the same electromagnetic wavelength as the transmitter (usually VHF, UHF or IR) and is physically attached to the output device such as a PA system or a closed system headset.

Here's an example of a top drawer wireless vocal microphone from Shure.


Shure Wireless Handheld Microphones

Shure Wireless Handheld Microphones

 
Shure ULXS24/58-SM58 UHF handheld wireless microphone systems include a wireless handheld cardioid microphone with an integrated transmitter, an 8 hour battery life, and an operating range up to 300 feet. This handheld wireless microphone system features Predictive Diversity, which anticipates and avoids sound dropouts. Buy Now This Shure handheld wireless microphone system delivers dependable, frequency-agile performance, along with clear channels and strong transmission. Learn MORE >>
 

See our article on wireless microphones for a more detailed discussion of the difference between handsfree and handheld wireless microphones as well at the problems of transmission and interference. Important issues discussed include Infrared (IR) vs Radio Frequency (RF), the type of antenna and the transmission frequencies used.


TYPES OF MICROPHONES - MICROPHONE PICKUP PATTERNS

The pickup pattern of microphones describes a three dimensional orientation in space relative to sound sources in the ambient environment.

In general, pickup patterns fall into one of three categories: unidirectional (cardioid), bidirectional (figure-8), and omnidirectional (boundary) configurations.

Unidirectional or Cardioid Pickup Patterns

 Microphones The unidirectional pickup pattern is the most popular configuration for microphones.

They pick up sound primarily from one direction - the front of the microphone capsule - allowing the audio engineer to isolate the signal source from other performance elements or background noise.

Cardioid microphones have a specific shape. As can be seen in the diagram at the right, the cardioid pickup pattern resembles the shape of a human heart, hence the name, cardioid.

You have probably seen a cardioid microphone in action when a reporter moves a handheld microphone back and forth in a live TV interview. This is because cardioid microphones can exhibit a "proximity effect" - a boost in low-to-mid frequencies - as the distance between the sound source and the microphone decreases. This can sometimes cause unwanted distortion of the audio signal if the distance between the sound source and microphone is not controlled.


 Microphones

Shure Unidirectional or Cardioid Microphones

 
Shure 588SDX unidirectional microphones include a uniform cardioid polar pattern that reduces feedback even in acoustically difficult locations, and a built-in windscreen that minimizes unwanted ambient noise. These unidirectional microphones are suitable for Buy Nowsound reinforcement, recording of speech, vocals and musical instruments. They are ideal for operation closer than usual to loudspeakers without the annoying squeal or howl caused by feedback. Learn MORE >>
 

Super-cardioid pickup patterns have an even narrower area of sensitivity than the classic cardioid and are used for very focused recording or live sound reinforcement. Super-cardioid pickup patterns are great for zeroing in on that perfect sweet spot for instruments and are common in instrument mics for drums and pianos. Super-cardioid pickup patterns are also ideal for live recording sessions where isolation is important, including minimizing signal bleed between a vocalist and their own instrument.


 Microphones

AKG D3800SM Super-Cardioid Microphones

 
The AKG D3800SM is a fantastic supercardioid dynamic vocal microphone. This mic features the first ever variable thickness diaphragm allowing it to be tuned to the desired resonant Buy Nowfrequency for a quantum leap in sensitivity sound quality. These supercardioid dynamic vocal microphones can be converted from wired to wireless, and feature studio quality frequency response characteristics ideal for performance needs. Learn MORE >>
 

 MicrophonesBidirectional or Figure 8 Pickup Patterns

The bidirectional or figure 8 pickup pattern is equally sensitive on the two opposing faces of the microphone which correspond to the front and rear of the diaphragm, while rejecting sounds from the sides. This pattern also exhibits the proximity effect found in cardioid patterns.

Bidirectional microphones are excellent for capturing a vocal or instrumental duet, and face-to-face interviews utilizing a stationary single microphone. Often these microphones are optimally positioned above a sound source. They're also great for isolating an instrument like a snare drum from the rest of the drum kit, and for facilitating certain stereo effects.


Bidirectional Figure 8 Microphones

Nady RMM-2 Bidirectional or Figure 8 Microphones

 
Nady RSM-2 Bidirectional Figure-8 Microphones provide great sound and performance at an affordable price. These microphones feature a bidirectional or figure-8 pickup pattern designed for recording on both front and rear sides, with extended sweet spots and slightly different frequency responses from front and rear side. Nady bidirectional microphones offer a choice of audio reproduction depending on placement for utmost versatility in dialing in Buy Nowthe desired “sound”. This microphone comes with an integrated yoke mic stand mount, XLR cord and a soft padded carrying case for easy transportation. Learn MORE >>
 


Omnidirectional or Boundary Pickup Patterns

 Microphones As the name implies, the omnidirectional pickup pattern collects sounds equally well from all directions and will deliver the most accurate representation of a total environment.

Omnidirectional microphones are used to capture room resonance along with the source, thereby yielding a much more open sound than that of the focused cardioid microphone. These microphones are great for vocal groups, Foley sound effects, and realistic recordings of acoustic instruments. The major drawback to omnidirectional mics is their sensitivity to feedback, necessitating proper placement in a live setting.

Omnidirectional pickup patterns exhibit significantly less proximity effect than cardioids, so these patterns are somewhat less sensitive to the movements of an animated vocalist, and tend to have less need for equalization (EQ.) While omnidirectional microphones cover 360 degrees of sound, they are apt to be more directional as frequencies increase — especially in larger capsules.


Shure Microflex Omnidirectional Boundary Microphones

Shure Microflex Omnidirectional Boundary Microphones

 
Shure Microflex MX393/O omnidirectional boundary condenser microphones are equipped with programmable DIP switches that offer the flexibility of Push to Mute, Push to Talk, or Push On/Push Off modes. Attractively designed with a low profile, professional appearance Buy NowShure omnidirectional boundary microphones are a high-quality solution for a range of applications, such as altars, boardrooms and distance learning centers. Learn MORE >>
 

Switchable Pickup Patterns

If you want maximum flexibility please note that a number of microphones can be switched from one pickup pattern to another. The Samson C03U is just one example of a hybrid with enhanced features.


 Microphones

Samson C03U Microphones with Switchable Pickup Patterns

 
The Samson C03U omnidirectional condenser microphone is an all-in-one that lets you choose from the top three pickup patterns available. These microphones feature dual internal shock mounted diaphragms with selectable omnidirectional, bidirectional and unidirectional pickup patterns, making them ideal for a Buy Nowvariety of specialized recording situations, like multiple vocalists, ambient room miking, or a group of people around a conference table recording a podcast. At a surprisingly low price, this microphone even plugs directly into a USB port. Learn MORE >>
 

The next section of this article reviews the features which different microphones offer such as fidelity, portability, compatibility or (though this is not strictly speaking a feature) price.

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Choosing Microphones for your Audio System

Microphone SpecialsIn this section of our self-help guide, our AudioLinks engineers create a checklist to help you choose the microphone that best suits your needs.

In general, you can differentiate among microphones by sound quality, fidelity in the high and low frequency ranges, ease of use, aesthetics, price and warranty. In fact, these same factors impact any choice among pro-audio equipment or accessories - not just microphones.

Some uses are so specialized that we've prepared specific articles to discuss the pros and cons of different microphones. For example, for DJs, KJs and masters of ceremony we've prepared a special article on which microphone solutions best fit their specific needs and budgets.

CHOOSING MICROPHONES FOR YOUR AUDIO SYSTEM - CHOOSING AMONG THE INTERNAL CONFIGURATIONS OF MICROPHONES

Dynamic, Ribbon & Condenser Microphones

Audio engineers and sound technicians classify microphones by dynamic, ribbon and condenser configurations.

Choose a Dynamic Microphone if:

•   You want a microphone that will be versatile
•   Your budget is limited
•   You need a microphone that will be durable
•   You use it for live vocals and recording
•   You work with relatively loud sound sources

Choose a Ribbon Microphone if:

•   You want to pick up a wide range of frequencies
•   You are looking for an extraordinarily rich representation of the original sound
•   You seek smooth, detailed sound
•   You want to capture the subtle nuances in a recording studio
•   You expect and appreciate subtle, sensitive sound

Choose a Condenser Microphone if:

•   You need versatility because you work in a variety of applications
for example speech as well as music
•   You want accurate sound reproduction and clarity
•   You like sound that is natural, clean and clear, with transparency and detail
•   You need exceptionally sensitive pickup, which requires phantom power for silent audio amplification


CHOOSING MICROPHONES FOR YOUR AUDIO SYSTEM - CHOOSING AMONG THE EXTERNAL CONFIGURATIONS OF MICROPHONES

Wired & Wireless Microphones

Choose a Wired Microphone if:

•   You want a microphone that will be durable and versatile
•   Your are looking for a mic with a classic look and sound (or something to do with your hands)
•   You need to overcome unexpected interference
•   Your budget is limited
•   You need to mike instruments

Choose a Wireless Microphone if:

•   You want freedom of movement
•   When you need handsfree operation choose a wireless lavaliere or headband microphone
•   You want to eliminate the cables that cause clutter or accidents
•   You desire ease of setup and no cable runs

•   You looking for discrete amplification without visible distractions

 

CHOOSING AMONG WIRELESS MICROPHONES

You may also wish to consider the choices among transmitters for wireless microphones:

•   IR vs. UHF/VHF TRANSMITTERS

•   UHF TRANSMITTERS vs. VHF TRANSMITTER


CHOOSING MICROPHONES FOR YOUR AUDIO SYSTEM - CHOOSING AMONG MICROPHONES PICKUP PATTERNS

Unidirectional, Bidirectional and Omnidirectional

Choose Unidirectional (also called Cardioid) Pickup Patterns if:

•   You want to control the source of input
•   You want to reject unwanted sounds such as room acoustics (reverberation), feedback or leakage
•   You are a reporter and or DJ and hold the microphone to someone while they are speaking
•   You are recording concerts where you are miking amps or instruments separately.

Choose Bidirectional or figure 8 if:

•   You want to capture the interplay of two sound sources like a vocal or instrumental duet
•   You can position microphones above a sound source for ambient room effect

•   You do face-to-face interviews utilizing a stationary single microphone
•   You want to be very selective about the peripheral sounds the microphone picks up


Consider Omnidirectional or Boundary if:

•   You want to deliver the most accurate representation of the total environment
•   You need a microphone for a boardroom conference table
•   You want realistic recordings of acoustic instruments

•   You record vocal groups with three or more singers
•   You want to collect sounds equally well from all directions

Consider Switchable Pickup Patterns if:

•   You want maximum flexibility
•   You want to expand your versatility
•   You work in a variety of different vocal applications
•   You want a microphone that can be switched from one pickup pattern to another
•   You want an all-in-one microphone

Well hopefully these hints and suggestions are enough to get you started.

Did you like this article and would you like to see more of the same? Do you have any questions?

Please fee free to call or email us at AudioLinks - The Home of Sound Solutions.


Microphone Manufacturers featured by AudioLinks:

AKG AcousticsAKG Acoustics has built an international reputation as one of the world's most elite suppliers of microphones, headphones and wireless systems. The signature “AKG Sound” is the basis for the popularity of their products, the result of impeccable workmanship and the highest standards.


Anchor AudioAnchor Audio is an industry leader in microphones and pro audio systems. Anchor Audio's 6 year warranty - the longest warranty in the Pro Audio industry - is available on all Anchor products bought through AudioLinks.com


Bosch MicrophonesBosch Microphones designs and manufactures Bosch Digital Congress Network microphones and conference systems. Bosch microphones are ideal for venues such as local government councils, hotel conference rooms, training and educational venues.


FenderFender is one of the most widely recognized manufacturers of microphones and pro audio gear. Fender manufactures a complete line of microphone equipment under the Fender brand, including the innovative Passport wireless microphone system.


NadyNady microphones are recognized internationally for their unique combination of quality and value. Nady has sold millions of wireless microphone systems worldwide, and continues to provide some of the most innovative and peak performing products on the market at highly competitive prices.


SamsonSamson designs and manufactures low-cost wireless microphones and instrument systems. Founded in 1980, the original Samson wireless products offered reliability at prices unheard of at the time. Samson audio products have had a lasting impact on the pro audio market and continue to break new ground even today.


SennheiserSennheiser microphones are designed to deliver the highest possible standards of performance, technology and design. Sennheiser makes top-quality microphones and tailor-made microphones in all areas of sound recording, microphones of every kind, ranging from vocals microphones to complete mic systems for musicals. Sennheiser microphones have become firmly established at the pinnacle of microphone technology throughout the world.


ShureShure has been dedicated to making microphones and audio electronics that help amplify, process and mix your sound. With a history of audio innovation spanning over 80 years, Shure has turned a passion for making great microphones and audio electronics into an obsession.

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Call or email us if you have any questions about which Microphones are right for you.

You may also wish to read our other product reviews on microphones.

Microphones - See All Microphones
Microphones -
Wired Handheld Microphones
Wireless Microphones -
Wireless Hand held Microphones
Wireless Microphones -
Wireless Hands free Microphones
Wireless Microphones -
Wireless Microphone Packages
Microphones -
Instrument Microphones
Microphones - Push to Talk & Boundary Microphones

           

 

 

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