What Is A Near-Coincident Pair Of Microphones? (+7 Examples)

Near-coincident pairs include many high-quality miking techniques for audio engineers and musicians to use effectively in their work.

What is a near-coincident pair of microphones? A near-coincident pair is any stereo miking technique that uses a pair of microphones spaced roughly 6-12 inches apart and angled symmetrically on either side of the centre. Near-coincident pairs are often preferred for their stereo image since their mic positions simulate human ears.

Near-coincident pair miking techniques include:

• DIN Pair
• EBS Pair
• Faulkner Array
• NOS Pair
• ORTF Pair
• RAI Pair
• Stereo Ambient Sampling System
• AB Technique (sometimes)

Let's dive deeper into what constitutes a near-coincident stereo pair of microphones and look at the near-coincident miking techniques mentioned above.

Definition Of A Near-Coincident Pair Of Microphones

Let's break down the phrase “near-coincident pair” to understand the miking technique protocol better.

Pair means that there is a pair of microphones. Therefore a near-coincident pair has two identical microphones in its array. Two microphones with very similar characteristics (frequency and polar response, sensitivity, etc.) could also work well, but two of the same mic is always ideal.

Near-coincident means that the microphones' relative positions are nearly coincident but not quite. In other words, there is some space between the microphones. Usually, this means the microphones are spaced a foot or less from one another.

This “near-coincident” spacing is a good thing. It somewhat simulates how we naturally hear sounds. Our ears are designed as a near-coincident pair, albeit with our heads in between, which creates a sort of baffle.

In addition to being a slightly-spaced pair of microphones, the near-coincident pair is a stereo miking technique. The microphones are pointed in the general left and right directions and are to be panned respectively in the mix to achieve the proper stereo image.

Applications Of Near-Coincident Pairs

Why would we want to utilize a near-coincident pair microphone technique?

Of course, each near-coincident pair is different (in mic positioning, direction, and in the microphone pair itself). Still, each provides its own realistic stereo field with reasonable compatibility with mono playback.

Applications of near-coincident pairs range from room miking to ambience miking outdoors to miking single sound sources in the studio.

These stereo miking pairs are often opted for over coincident and spaced pairs because of their natural stereo sound capture.

For more information on coincident and spaced pairs of microphones, check out the following My New Microphone articles:
• What Is A Coincident Pair Of Microphones? (With 2 Techniques)
• What Is A Spaced Pair Of Microphones? (With 3 Techniques)

These miking techniques perform well at most distances from their sound sources. They are also fairly compact and easy to set up and optimize before/during recording.

The stereo image capabilities vary from one near-coincident pair to the next. Each pair has its own pros, cons, ideal stereo image, and potential phasing issues.

Because of the wide definition of near-coincident pair, these miking techniques are the most popular stereo miking techniques.

Why would we want a stereo image?

A true stereo image captured by a near-coincident pair adds realism, width, and depth to a mix. This is largely due to the fact that we naturally hear sound in stereo. To further this point, I'll restate that our ears are set up as a near-coincident pair.

When at a distance, near-coincident pairs are fully capable of capturing a realistic sound from the acoustic environment. This helps to either create a general stereo recording or add depth and width to a recording that focuses on close-miking individual sound sources.

At closer range, near-coincident pairs can add excitement and width to individual instruments. However, these techniques can sometimes lead to a poor centre image and phase issues when positioned too close to a sound source.

When setting up near-coincident pairs, be sure to listen for potential phasing issues.

It's also good practice to set stereo miking arrays equidistant from low-end frequency sound sources (kick drums, bass guitar cabinets, etc.) in order to maintain a strong centre image with bass frequencies.

For more information on microphones and phase, check out my article Microphone Polarity & Phase: How They Affect Mic Signals.

Common Near-Coincident Pair Techniques

Near-coincident pair miking techniques include:

• DIN Pair
• EBS Pair
• Faulkner Array
• NOS Pair
• ORTF Pair
• RAI Pair
• Stereo Ambient Sampling System
• AB Technique (sometimes)

DIN Pair

What is the DIN pair microphone technique? DIN pair is a near-coincident pair stereo miking technique. It consists of a pair of cardioid microphones spaced 20 cm (7.9 in) apart, angled at 90° from one another (45° from the “front axis”), and pointing outward.

The DIN pair was developed by DIN, the Deutsches Institut für Normung (German national standards organization).

Like all near-coincident pairs, the DIN pair offers a mixture of intensity stereo (sound level difference between the mics) and time stereo (phase difference between the two mics).

The unidirectional cardioid microphones are most sensitive in the directions they point toward. Therefore the stereo image will be based on the centreline between the mics but will be most sensitive at 45-degrees to the left and to the right (relative to that centreline).

Though the cardioid mics are most sensitive to the left and right, their relatively close proximity to one another results in a fairly cohesive centre image. This is because much of the sound coming from the direction of the centre line will reach both mics at relatively the same time and have a decent impact on the mic signal levels.

The sound from the rear of the DIN pair will be relatively quiet since the cardioid mics reject sound from their rear null points.

Thus, the DIN pair is great for capturing a stereo image in a certain general direction. It also excels as a room mic when pointed toward instruments. It can be positioned closer or further and will likely pick up more direct sound than diffuse sound due to the rear rejection.

The DIN pair works well at short distances from piano and small ensembles. Position the DIN pair close enough to capture a dry signal but far enough for the sound to fully develop from the sound source and cause subtle differences in sound between the two mics.

EBS Pair

What is the EBS Pair? The EBS pair is a stereo miking technique that utilizes a pair of cardioid mics. This near-coincident pair has its mics spaced 25 cm from one another at an angle of 90°.

The EBS pair was developed by Eberhard Sengpiel of the Berlin University of the Arts.

This near-coincident pair is very similar to the DIN pair. The difference being that the EBS pair are spaced 25 cm apart while the DIN pair are spaced 20 cm apart.

This seemingly small difference in spacing gives the EBS pair a slightly wider stereo image at the expense of the centre sound capture. The EBS should also be positioned a bit further from its intended sound source for better stereo capture and fewer phase issues.

The EBS is a great near-coincident pair for capturing the sound of a room without too much reverberation and reflections (due to the rear rejection of the cardioid mics).

The EBS pair is an excellent choice for recording full drum kits (either as room mics or overhead mics). It also excels at capturing a stereo image of small ensembles.

Faulkner Array

What is the Faulkner microphone array? The Faulkner array is a near-coincident pair stereo miking technique that utilizes two bidirectional mics. The mics are spaced about 8 inches apart and both face forward toward the intended sound source.

This near-coincident pair technique was developed by Tony Faulkner, a British recording engineer.

Unlike many of the microphone pairs featured in this article, the Faulkner Array has both its mics pointed forward with no angle between them. This allows further positioning from the sound source without risking an overly thin mix with an exaggerated stereo image.

The Faulkner array sounds great at closer distances (though I wouldn't suggest close-miking any particular instrument with this array). It also sounds great at a distance from the sound source(s).

The rear sensitivity of the bidirectional microphones allows for a decent capture of initial reflections from the rear surfaces. Distancing the Faulker array from the sound source will provide more reflection in the mic capture relative to the direct sound.

Null points to the sides of the bidirectional microphones help reduce the overall amount of room reflections and reverberation in the mic signals. This improves the sound of the microphones even more as they are distanced from the intended sound sources.

For more information on the bidirectional microphone polar pattern, check out my article What Is A Bidirectional/Figure-8 Microphone? (With Mic Examples).

The Faulkner Array sounds great on large and small ensembles as well as on single instruments.

NOS Pair

What is the NOS pair miking technique? The NOS pair is a near-coincident stereo miking technique that uses two cardioid microphones. The cardioid capsules are spaced 12 inches apart and angled at a 90° angle, pointing outward.

The NOS pair was developed by the Nederlandse Omroep Stichting (Dutch Broadcast Foundation).

Like the aforementioned DIN and EBS pairs, the NOS pair has two cardioids angled at 90° (45° left and 45° right of an imaginary centre line that points toward the intended sound source). The NOS pair spaces its mics a bit further apart at 12″ (30.5 cm) compared to the DIN's 20 cm and the EBS's 25 cm.

The NOS pair yields a decently wide stereo image with relatively good mono compatibility.

Cardioid microphones reject sound from the rear. This helps the NOS pair focus on the intended sound source without capturing too much environmental noise and reflections.

ORTF Pair

What is an ORTF microphone pair? The ORTF pair is a near-coincident stereo miking technique established by the ORTF. It utilizes two cardioid mics spaced 17 cm (6.7″) apart and at an angle of 110 degrees. This popular technique yields a spacious sound while maintaining good mono compatibility.

The ORTF pair was developed circa 1960 at the Office de Radio Diffusion Télévision Française (ORTF) at Radio France.

The idea behind the ORTF stereo miking technique is that it is well suited for reproducing stereo in the way that our ears naturally hear stereo information in the real world. The spacing of the microphones simulates the distance between the human ears. The angle between the two cardioid microphones emulates the effect the human head has on the sonic differences between the ears.

Note that the ORTF pair's stereo ability is based on the microphones' time/phase difference and amplitude/level difference. It does not actually have a baffle (or an artificial head) to cause physical interference between sound sources and the microphone.

The result is a realistic stereo field with reasonable mono collapsibility. Since the cardioid polar pattern rejects off-axis sound, the ORTF mics pick up less ambient room characteristics. This means that the mics can be placed farther from the sound sources, resulting in a favourable blend of direct and diffuse sounds.

The ORTF pair sounds great at most distances from its intended sound sources and is used in the studio, outdoors, on the stage, and in other scenarios where a simple and clean stereo miking setup is needed.

The ORTF pair is a common stereo miking technique, if not the most popular technique. Because of this, many purpose-built microphone mounts have come into the market, making it easy to set up the ORTF pair.

One such microphone mount is the K & M Microphone Bar:

RAI Pair

What is the RAI microphone pair? The RAI pair is a near-coincident stereo miking technique that specifies a pair of cardioid mics spaced 21 cm apart and angled at 100°. The RAI pair was established by the Radio Audizioni Italiane, Italy’s national public broadcasting company.

The RAI technique was developed by the RAI, Radiotelevisione Italiana (known until 1954 as Radio Audizioni Italiane), the Italian broadcasting agency.

This technique is actually very similar to the ORTF pair mentioned above. However, it is much less popular in studios around the world.

Stereo Ambient Sampling System

What is the stereo ambient sampling system miking technique? The stereo ambient sampling system (SASS) is a baffled near-coincident stereo miking technique that used a pair of omnidirectional mics positioned less than a foot apart, angled at roughly 30°, and separated by a centre baffle. SASS yields a natural stereo sound and is great for recording ambience.

The Stereo Ambient Sampling System (SASS) was developed by then Crown Audio engineer Michael Billingsley.

Originally, SASS was designed as a baffled unit that featured two microphones (or at least their capsules). SASS was built as a quasi-binaural system, using winged baffles around the microphones to simulate the human head's effect on the ability for sound to reach the ears.

These strange systems sometimes used boundary mics on their baffles and other times had omnidirectional mics positioned within their baffles.

Crown Audio released these products under the name SASS. One standout model is the (now discontinued) SASS-P Mk II:

Since the birth of the Stereo Ambient Sampling System (and the discontinuation of the original Crown Audio SASS products), some audio engineers have co-opted this SASS baffled technique and have changed it to their own liking. Nowadays, the SASS looks more like the diagram featured above.

Today's SASS techniques utilize two omnidirectional mics with a baffle between them. The mics are positioned less than 12 inches from one another. This strategy aims to simulate the way our ears naturally hear sound.

For more information on the omnidirectional microphone polar pattern, check out my article What Is An Omnidirectional Microphone? (Polar Pattern + Mic Examples).

SASS techniques are designed to sound good where sound waves naturally sound good to us. In other words, we may move around a room until we hear a sweet spot, set up the SASS where our head was, and the miking technique, if properly constructed, will sound decent.

AB Technique

What is the AB miking technique? The AB miking technique is for stereo applications and has two identical omnidirectional microphones at equal height, facing forward, and spaced 12 to 48 inches apart. At 12 inches, AB could be considered a near-coincident pair, while at 48 inches, AB would be considered a spaced pair technique.

The AB near-coincident pair provides us with the weakest stereo image of all the techniques in this article. AB pairs rely on time and level differences between the mics to attain a stereo image.

Omnidirectional mics are sensitive to sound from all directions (hence the name), so much the AB technique will be sensitive to room reflections and reverberation as well as the direct sound of the intended sound source. For this reason, it's important to position the AB pair closer to the intended sound source than miking techniques that use cardioid mics.

At these closer distances, there will be larger phase differences between off-axis sounds in the two mics, which will widen the stereo image.

Alternatively, the AB technique works well as a narrow stereo room mic setup or a narrow stereo ambience miking setup.

Related Questions

What is an XY mic? An XY mic is a stereo microphone with two capsules set up in a coincident XY stereo pattern. These two capsules are placed very closely together and point outward with an angle of 90°-135° between them—the mics output two signals that are later panned in the mix to achieve a stereo image.

For a more detailed read on stereo microphones, check out my article Do Microphones Output Mono Or Stereo Signals?

How do you hold a cardioid microphone? Cardioid microphones are unidirectional, and so it's important to point them at the intended sound source. When speaking or singing, this means holding the mic so that it points at our mouth. Cardioids have a rear null point, so it's beneficial to point them away from loudspeakers for better gain-before-feedback.

To learn more about properly holding microphones, check out the following My New Microphone articles:
• How To Hold A Microphone When Public Speaking And Presenting
• How To Hold A Microphone When Singing Live

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