Learn about the different types of microphones and their uses. Tell your cardioid from your hypercardioid in our ultimate guide to microphones.
Microphones come in three main types: cardoid, condenser, and ribbon.
Each one has its advantages and disadvantages, and is best suited to a different application when recording.
In today’s article we’ll learn about the 3 different types of microphone, and when they’re best used.
We’ll cover microphone polar patterns, how they work, and the benefits of each.
Considerations when Recording
When considering the right types of microphone, you need to bear in mind the possibility of collecting unwanted background noise, especially if the microphone is to be used for live amplified performances, in which case feedback can be a massive issue.
Also, you should think about what type of sound source is going to be amplified or recorded. The sound and volume levels of acoustic instruments widely vary from electric instruments, and these, in turn also vary greatly with the characteristics of the human voice. Different mics perform better when picking up different types of sound sources.
You should also be thinking of the aesthetics of the microphone. Should it be visible to an audience? Or is it going to be used in a studio—in which case the matter of how the microphone looks doesn’t really matter whatsoever.
If the microphone is going to be used alongside filming, then it needs to be able to still pick up a good sound level even when it has to be kept out of the visual scene, out of the frame.
Of considerable importance when recording outside is the humble windshield. This stops unwanted knocking sounds from butting in on your recording or amplification when a sudden burst of wind starts up. On a similar note, a pop shield is of vital importance when recording vocals or spoken voice in order to reduce or eliminate plosive “p” or “b” sounds from popping up on your recording.
Microphone Type 1: Cardioid
Cardioid microphones have a front focus polar pattern (if you’re unfamiliar with polar patterns then jump to the next section for an explanation) which allows them to catch sounds in front of them while rejecting everything else. For this reason, they are also known as unidirectional microphones. The result of this is to isolate ambient sounds which in a lot of situations are not wanted—for example, live music performances. The cardioid polar pattern makes this type of microphone great for noise reduction and the suppression of feedback.
Cardioid mics are by far the most popular type of microphone, being used at the majority of live performances ranging from small-time karaoke sessions to the largest concerts in arenas.
These microphone types are particularly suited to picking up louder instruments such as drums or guitar amp speakers. The positioning has a significant effect on the sound coloration of the source, meaning that exact positioning is required when using cardioid microphones.
There are different types of cardioid mics, like the super or hypercardioid microphone, which have an even narrower sensitivity than standard cardioids. These are known as different polar patterns. The result is greater feedback resistance and even further improved isolation when miking something specific, making them even more suited to the loudest sources of sound and the noisiest environments.
Cardioids are the best choice of microphone for live vocal performances, especially when the volume on the stage is loud and feedback is a possible issue.
Cardioid microphones are also a great choice for capturing the bombastic sound of acoustic drum kits. Additionally, they’re brilliant for picking up guitar amplifiers at close proximity, but need to be positioned correctly for the best sound.
Microphone Type 2: Condenser
These microphones have a configuration which functions as a capacitor—a small electrically charged diaphragm attached to a metal back plate. The moving of the diaphragm by the change in sound pressure changes the capacity of the capacitor. This transforms the acoustic signal into an electrical current. The sound pressure causes the diaphragm to shake, and it is these vibrations which alter the capacitance, which results in the audio signal.
This capacitance basis sets condensers apart from the majority of mics which use moving coils. Consequently, the sound quality of a condenser microphone can be significantly better than that resulting from other types of mic.
The word “condenser” used to be used synonymously for capacitor, but nowadays the term is hardly ever used outside the realm of microphones.
The improved audio fidelity means these mics are ideal for studio recording, although bear in mind that this type of microphone does require either an external power supply, batteries inside the microphone itself, or phantom power which is supplied by the PA/mixer’s input.
Older mixers tend to not have phantom power supplies on the microphone inputs, so it is advisable to ensure that the mixer you want to use has phantom power before you purchase a condenser microphone that requires it.
There is a huge range of condensers available today, of varying quality, and shapes and sizes.
Condenser microphone types are used in applications as widely ranging as telephone transmitters, cheap karaoke setups, to the best available high-fidelity recording mics. Generally, they are capable of producing a great audio signal.
Condensers can often be more fragile than other types of microphone so they should be handled with respect. In return for this fragility and sensitivity, a condenser mic gives a much smoother and more natural sound, especially at the higher frequencies.
Small-diaphragm condenser mics are less than an inch in diameter and are particularly well suited to picking up the high frequency sounds such as drum kit cymbals and hi-hats, as well as recording acoustic instruments. However, they require either a battery or phantom power in order to operate.
Small-diaphragm condensers can react the high frequency sound changes considerably quicker than their large diaphragm condensers. Despite this, high-fidelity large-diaphragm condenser microphones are still great for picking up the subtle nuances of unamplified acoustic guitars, although cardioids can also be considered where noise and/or feedback is a possible issue.
Large-diaphragm microphones are generally remarkably sensitive, almost always requiring external power and a specific suspension mounting in order to isolate the microphone from unwanted external vibrations (these would otherwise be picked up by a sensitive mic and add an unwanted “knocking” effect to your sound output).
Because of the need for this suspension mounting—as well as their generally large size (much bigger than small diaphragm condensers)—large diaphragm condensers are usually unsuitable for applications where space is limited, such as when miking a drum setup.
As an all-purpose recording mic, however, they are unmatched and are consequently ubiquitous in studios for recording an enormous range of instruments (including acoustic guitars, pianos, drums), as well as voices. LDCs (large-diaphragm condensers) tend to produce a lot less self-noise than small-diaphragm condensers.
Large-diaphragm condensers can cost a lot of money (they are among the best available mics after all). Now though, a host of affordable models have come on the market which emulate the function and design of the most expensive microphones. Subsequently, fantastic sounding home/non-professional recording is available to all with much-reduced overhead.
If you’re looking for a vintage looking and sounding recording microphone, look no further than a tube condenser mic. These give any recordings a warm, rounded sound which mimic the old recording methods. Like other types of condensers, they require either an external power supply, phantom-powered mixer, or a microphone preamp.
Microphone Type 3: Ribbon
A light metal ribbon picks up the air velocity as well as the displacement of air, allowing the capture of higher frequencies with a warmer coloration than with other mics, softening the sound in the process. The thin ribbon vibrates in response to air movement, varying the voltage and producing the audio signal.
The extremely delicate ribbon microphone used to be one of the most popular types of mic on the market. While they have lost their former dominance of the radio industry, these mics still have their uses, primarily in lending audio recordings a warm vintage sound.
The original design bi-directional ribbon microphones from the 1930s and 1940s are unmatched for their classic looks and high-quality vintage performance, although they are incredibly delicate and have to be handled with the utmost care.
Arguably a result of nostalgic rose-tinted spectacles, ribbon mics are considered by some to be the type of microphone which provides the most natural sound in recording.
Some ribbon mic models have externally adjusted internal baffle positions, allowing operators to choose from a variety of response patterns.
The modern ribbon microphone is a lot more reliable and much sturdier than their antecedents, allowing them to be used alongside other microphones—especially when wanting to pick up a warmer, more open sound.
Of all the types of microphones, this is historically the most well-known for picking up voices, although they are also infrequently used to record piano, guitar amps, woodwind, brass, and upright bass.
This is the span of a microphone’s field of sensitivity. In other words, the directions from which sound is either picked up or ignored.
To illustrate, omnidirectional mics pick up sound from all around; bi-directional mics respond to sound input from left and right, while not from the front or back; unidirectional mics hear sounds for the most part only from a single direction, excluding all other sounds from other directions.
Omnidirectionals (also known as non-directional microphones) are great for a host of purposes—they take in a huge range of sounds from all directions. This is the ideal microphone for recording or amplifying voices in group discussions. This type of microphone really is ubiquitous; it’s found as the internal mic in a lot of video equipment. They do however, necessitate being positioned close to the subject in order to pick up good-quality sound with low noise.
Cardioid microphones have polar patterns which are vaguely heart shaped (the name “cardioid” comes from “cardiac,” meaning heart) allowing the mic to be at its most sensitive in response to sound from forwards and off to the side, but not sensitive to sounds behind it. The cardioid polar pattern is great for live performance where you want to reject the noise of the crowd.
This type of microphone is the stereotypical “news reporters’ mic” which offers a great compromise between directional sound pickup and room for error (for instance, if the broadcast journalist didn’t put the mic exactly in the sweet spot for the interviewee, then the mic would still pick up their voice with a good audible sound level).
Even more picky is the supercardioid microphone which responds to more sound from in front, but responds less to the sides. The most selective type of cardioid mic is the hypercardioid microphone which accepts even more of the sound in front of it, but even less from surrounding areas. When it comes to supercardioid vs hypercardioid, it really depends on your purpose for recording. The cardioid patterns are extremely popular and versatile.
Unidirectional mics are used in so-called “shotgun mics” which are ideal for focusing on specific sounds while blocking out unwanted ambient noises. There is little room for error with this type of mic as it can be quite unforgiving regarding picking up sound outside its scope. Unidirectional mic operators have to be highly skilled in order to pick out individual voices as this polar pattern requires them to point the mic directly at the subject.
Selecting the correct polar pattern for your application is vital to ensuring the sound being picked up is clean, distinct, and not muddled with background noise. Equally important is the reduction of feedback. Through preventing the accidental pick-up of output sound, feedback can be minimalized with the right type of microphone and suitable polar pattern.
Choice of Microphone
When thinking about microphones, it’s important to bear in mind the type of recording or amplification technique for which the mic will be used.
For close miking, where the mic is held really close to the sound source, the result is a dry sound with minimal reverb. In this case you might favor a warmer sound such as that found from certain types of condenser mics, or a ribbon microphone.
Room miking requires two mics, and is a standard method for recording rhythm guitar. Ambient miking, placing the mic at a distance from the sound source, requires a highly sensitive microphone, although choosing a directional mic for this purpose would undermine the purpose of this method somewhat, as it is designed to provide a broad, natural mix of the sound source.
That brings us to the end of our guide to microphones. Make sure and come back soon as we’ve got lots more coming at Home Recording Pro over the next few weeks and months. Follow us on Facebook to stat in the loop with all the guides and reviews of the top recording equipment that you don’t want to miss.
Make sure you get recordings of the highest quality and check out our guides to soundproofing doors and windows. We’ve got some awesome tips that can be done on a budget. They can make a huge difference to the fidelity of those tracks.
By Galak76 Creativecommons.org, via Wikimedia Commons