The Complete Guide To Microphone Polar Patterns

The polar pattern (along with frequency response) is the most important specification of a microphone. It tells us the directional sensitivity of the microphone. There are plenty of polar pattern responses in the tens of thousands of microphones on the market.

Here is a list of all the microphone polar patterns:

• Omnidirectional
• Bidirectional (Figure-8)
• Cardioid
• Supercardioid
• Hypercardioid
• Subcardioid/Wide Cardioid
• Lobar/Shotgun
• Boundary/PZM
• Infinitely Variable*

In this complete guide, we'll discuss what polar patterns are, how these patterns are achieved in microphones; and we'll take a deep look into each of the polar patterns with mic examples.

Note that “polar pattern” is synonymous with “polar response,” “directional response,” “directionality,” and that I will use these terms interchangeably throughout this article!

As with most in-depth guides, a table of contents is highly beneficial:

What Is A Microphone Polar Pattern?

This question seems like a good place to start.

What is a microphone polar pattern? A polar pattern is a representation of a microphone's directional sensitivity to sound pressure. In other words, polar patterns tell which direction(s) a mic will be sensitive to picking up sound and which direction(s) a mic will reject sound.

Polar pattern specifications are expressed qualitatively and quantitatively in microphone data/specs sheets.

Qualitatively, microphone polar patterns generally fall into one of the camps mentioned above. I'll restate them here:

• Omnidirectional
• Bidirectional (Figure-8)
• Cardioid
• Supercardioid
• Hypercardioid
• Subcardioid/Wide Cardioid
• Lobar/Shotgun
• Boundary/PZM
• Infinitely Variable*

These terms give us a general idea of how the given microphone will react to directional sound waves, but it doesn't give us an in-depth picture of the polar pattern.

Quantitatively, microphone polar patterns are drawn out as graphs on polar plots. Here are the 3 most common polar patterns and their generic polar pattern graphs:

Looking deeper at the base of the polar pattern graphs (pictured to the right), we see that the graph is laid out on top of a 360° polar plot (hence the name “polar pattern”). Typically there are outward lines draw at every 30° around the circle.

Additionally, there are inner circles that represent a drop in microphone sensitivity. Each inner circle typically represents a difference of 5 dB in sensitivity.

So when we see a cardioid polar pattern, for example, it graphically looks like this:

And we can see that the basic cardioid pattern is most sensitive at 0° (where it points), and its pattern shows 0 dB at 0°. To the sides (90° and 270°), the cardioid pattern is 6 dB less sensitive (the graph shows this by coming in slightly centre of the -5 dB circle). And to the rear, the [ideal] cardioid polar pattern completely rejects all sound.

Of course, this is an ideal pattern, and in reality/practice, no microphone is ideal. Not only are microphones not ideal, but sound itself has interesting properties that affect microphone polar response.

Back to table of contents.

Microphone Polar Patterns Are Frequency-Dependent

It's critical to note that the microphone polar pattern is frequency-dependent!

• Microphones become less directional at lower frequencies.
• Microphones become more directional at higher frequencies.

This is true of every microphone and every polar pattern.

For this reason, quality polar pattern graphs will actually show multiple frequency-specific patterns on their graphs.

Let's take a look at some real examples of the above-mentioned cardioid polar pattern.

To the right is the polar pattern of the Neumann U 87 AI (in cardioid mode), and to the left is the polar pattern of the Neumann KM 184. Both these microphones will be covered in more detail later in the article.

I chose Neumann mics here because their polar response graphs are clean well-drawn.

So in each of the above graphs, we have lines representing the mic polar response at 125 Hz, 250 Hz, 500 Hz, and 1,000 Hz (on the left of the vertical centre line).

We then have lines representing the polar response at 2 kHz, 4 kHz, 8 kHz, and 16 kHz (on the right of the vertical centre line).

Let's take a look at each of these in more detail:

Neumann U 87 AI (Cardioid Mode) Polar Pattern Example

As we can see above, the U 87 is practically a subcardioid/wide cardioid pattern below 250 Hz. The rear sensitivity “null point” begins tightening around 500 Hz and has max rear-rejection at 1 kHz. The rear lobe of sensitivity that appears at 2 kHz and above is reminiscent of a supercardioid/hypercardioid pattern.

Also, as the frequencies increase, the side response of the U 87 tightens up. It's roughly -5 dB at 125 Hz; the typical -6 dB at 1 kHz; -10 dB at 4 kHz and 8 kHz; and practically a null point at 16 kHz.

Neumann KM 184 Polar Pattern Example

As we see here, the KM 184 has a “cleaner” cardioid pattern than the U 87. This is due to the differences in capsule design. The KM 184 has a smaller diaphragm and is, therefore, more consistent. The U 87 is a multi-pattern mic, and so it's not necessarily specialized as a cardioid.

Even still, the KM 184 tends toward subcardioid at 125 Hz and below and, at the same time, toward supercardioid/hypercardioid at 16 kHz and above.

To add to the complexity, it's also worth noting that the 0° – 0 dB point of sensitivity will change according to the microphone frequency response. The two Neumann mic examples are fairly flat, so this is not a huge issue. However, it's worth noting that each frequency-specific pattern is relative to the 0° on-axis sensitivity of that individual frequency.

To read about frequency response, polar response, and the other critical microphone specifications, check out my article Top 5 Microphone Specifications You Need To Understand.

Back to table of contents.

Understanding The Angles: “On-Axis” Vs. “Off-Axis”

So far, we've looked at the names of the various polar patterns and have a good idea of how polar patterns are laid out on graphs. However, we must understand exactly where that 0° point is in real space.

This 0° point is known as the “on-axis” direction of a microphone. Sound sources from all other directions are considered to be varying degrees “off-axis.”

• On-axis: An imaginary axis line that runs outwardly perpendicular to the centre of the front of a microphone diaphragm. The direction in which the microphone effectively “points.”
• Off-axis: The degree to which a sound source is positioned relative to the on-axis line. 180° off-axis, for example, would be directly behind the microphone.

Note that on-axis and off-axis sounds are physically in 3D space, though polar pattern graphs are represented in 2D.

So how do we figure out the on-axis line of a microphone? It mostly comes down to answering the following: is the microphone a top-address microphone or a side-address microphone?

Top-Address Vs. Side-Address Microphones

Distinguishing between top-address and side-address is critical if we are to understand microphone polar patterns.

Note that top-address is also referred to as “front-address” and “end-address.” Note also that “top/front/end-fire” and “side-fire” are also synonymous terms.

Let's define top-address and side-address.

Top-Address (AKA End Address Or Front Address)

What is a top-address microphone? A top-address microphone has an on-axis line pointing out of its top. Top-address mics have capsules at the top or end of their bodies and are most sensitive in the direction they point in. Pencil mics and most handheld mics are top-address.

Top-address microphones, by the nature of their design, cannot be bidirectional.

The aforementioned Neumann KM 184 is a top-address microphone. Its on-axis line is pictured below:

A typical top-address microphone (like the KM 184) will be practically symmetrical around its on-axis line. Therefore, the polar pattern response graph would hold true along any 2D plane centred on the on-axis line.

Side-Address

What is a side-address microphone? A side-address microphone has an on-axis line pointing out of its side. Side-address mics are most sensitive to sound coming from the side rather than “where they point.” Most ribbon mics and large-diaphragm condenser mics are side-address.

The aforementioned Neumann U 87 AI is a side-address microphone. Its on-axis line is pictured below:

The polar pattern response graph of a typical side-address mic (like the U 87 AI) is represented along the horizontal plane in the above image. There would be slight differences in other planes due to the physical body of the microphone.

Telling The Difference Between Top And Side-Address Microphones

It's generally easy to differentiate between top-address and side-address microphones. The Neumann mics mentioned above are great examples of each.

The following microphone types are typically (but not always) top-address:

• Pencil mics (like the Neumann KM 184)
• Small-diaphragm condenser mics (like the Neumann KM 184)
• Moving-Coil Dynamic Microphones
• Handheld mics
• Shotgun mics
• Modular mics
• Instrument mics

The following microphone types are typically (but not always) side-address:

• Large-diaphragm condenser mics (like the Neumann U 87 AI)
• Multi-pattern microphones (like the Neumann U 87 AI)
• Tube mics
• Ribbon mics

However, sometimes a microphone's address type is not obvious. One famously problematic case is the Sennheiser MD 421 II (pictured below).

The Sennheiser MD 421 looks similar to a typical side-address microphone. It even has a centre housing piece in the middle of its grille to suggest having a side-facing large-diaphragm.

This is not the case. The Sennheiser MD 421 is, in fact, a top-address microphone. Its on-axis line is pictured below:

So it's usually easy to determine whether a microphone is designed as top or side-address. In the odd case that you're unsure, check the mic's specifications/datasheet or do a quick Google search to find the answer.

Throughout the rest of this article, I'll note whether an example microphone is top-address or side-address.

To learn more about top top-address and side-address microphones, check out my article What Are Top, End & Side-Address Microphones? (+ Examples).

Back to table of contents.

Off-Axis Colouration Of Polar Patterns

What is off-axis colouration in a microphone? Off-axis colouration is the general term for the difference between a microphone's frequency response specification (measured on-axis) and its actual frequency response to sound off-axis. Microphones sound different when capturing sound off-axis and off-axis colouration helps explain this.

To understand the off-axis colouration of a microphone, let's first look at the mic's frequency response.

The frequency response of a microphone represents its on-axis frequency-dependent sensitivity to sound. The keyword here is “on-axis.”

Frequency response curves/graphs give us a clear visual representation of a mic's sensitivity to sounds across the spectrum of human hearing (20 Hz – 20,000 Hz).

So how do we then determine a microphone's off-axis colouration? By looking at its polar response graph.

The more single frequency plots on a polar response graph, the better we can understand the mic's off-axis colouration.

Remember, the sensitivity shown in a polar response graph is relative to the 0° reference point (and, therefore, the frequency response specification of the mic).

Also, recall that all microphones become more directional at higher frequencies and less direction (more omnidirectional) at lower frequencies.

This means that, generally, a microphones' off-axis colouration will be lacking in top-end relative to its on-axis response. It also means that in the null points of a polar pattern, the mic may very well remain sensitive to low-end frequencies.

Pressure Vs. Pressure-Gradient Microphones

To deeply understand microphone polar patterns, it's useful to know about the two main acoustic principles of microphones: pressure and pressure-gradient.

Pressure Principle

What is a pressure microphone? A pressure microphone is any mic that has one side of its diaphragm open to external sound waves, and the other side closed in a fixed pressure system. All pressure mics are considered omnidirectional since sound pressure is a scalar quantity.

The lack of directionality and relatively easy tuning of pressure principle microphones make them a popular choice for omnidirectional mics.

Because a pressure microphone only has one side of its diaphragm exposed to external sound pressure, it exhibits no proximity effect and is nearly immune to vocal plosives.

Pressure-Gradient Principle

What is a pressure-gradient microphone? A pressure-gradient microphone has both sides of its diaphragm at least partially open to external sound waves. Pressure-gradient mics make up all the directional dynamic and condenser mics. Pressure-gradient capsules even make up most of the omnidirectional patterns in multi-pattern mics.

The truest form of a pressure-gradient microphone yields a bidirectional (figure-8) polar response. This is the natural pattern that occurs when both sides of the diaphragm are equally open to sound pressure.

As we see to the right, the bidirectional pattern is symmetrical in its sensitivity to the front and rear of its diaphragm (positioned in the centre of the graph).

The difference between a bidirectional mic's capturing of sound to the front and rear is not in amplitude but in phase. A sound source to the rear will push and pull the diaphragm in the exact opposite way that an equal but front-facing sound source would.

Because there is pressure variation on both sides of the pressure-gradient diaphragm, these microphones exhibit proximity effect and are vulnerable against vocal plosives.

Note that any directional microphone functions on the pressure-gradient principle. The bidirectional pattern is the truest form of a pressure-gradient mic, but all directional microphones have both sides of their diaphragms exposed to external sound pressure.

Unlike bidirectional mics, the unidirectional microphones are designed with acoustic labyrinths that impede and delay the external sound waves from reaching the rear of their diaphragms. The amount of delay and attenuation between the diaphragm's front and rear yields the various directional polar patterns.

We'll discuss this in greater detail on a pattern-by-pattern basis later.

Combining Pressure And Pressure-Gradient

One method of explaining the cardioid microphone polar pattern (which we'll get to shortly in this article) is as a 50/50 combination of the pressure and pressure-gradient acoustic principles.

In other words, the superposition of the true pressure principle (omnidirectional polar pattern) and the true pressure-gradient principle (bidirectional polar pattern) yields the true cardioid polar pattern.

This is explainable with phase.

All sound waves that react with the pressure/omni mic only react with the front side of the diaphragm and are, therefore, all positive polarity.

Conversely, as noted above, the pressure-gradient/bidirectional diaphragm reacts with positive polarity to the sounds coming from its front side. It reacts with negative polarity to those sounds coming from its rear side.

So the positive phase to the front adds together while the opposite phases to the rear cancel each other out, culminating in a null point of zero-sensitivity at 180° in the cardioid pattern.

Recap On Pressure Vs. Pressure-Gradient Mics

So basically, microphones that work on the pressure principle are always omnidirectional.

Pressure-gradient microphones make up the rest of the polar patterns, and two pressure-gradient capsules can even be combined to achieve an omnidirectional polar pattern.

Unidirectional microphones can be explained as a combination of the truest forms of pressure (omnidirectional) and pressure-gradient (bidirectional) patterns. However, it's critical to note that unidirectional microphones are, in fact, pressure-gradient mics because both sides of their diaphragms are exposed to external sound pressure.

For a detailed article on pressure and pressure-gradient mics, check out My New Microphone's Pressure Microphones Vs. Pressure-Gradient Microphones.

Back to table of contents.

How Are Microphone Polar Patterns Measured?

So how do microphone manufacturers accurately measure the polar patterns of their microphones?

It starts with a pinpoint sound source. This is typically a calibrated loudspeaker that is capable of producing equal-level tones across the frequency spectrum.

The microphone being tested is positioned at a set distance from the loudspeaker. A tone is projected through the loudspeaker, and the microphone is rotated 360° about the centre of its capsule. It's important to keep the centre of the front of the diaphragm stationary as the mic is rotated. This ensures the most accurate measurement.

As the microphone is rotated, its output level is measured against its 0° on-axis output level. The relative output signal strength is then plotted according to the angle-of-incidence of the sound source.

This process is repeated at however many single-frequency tones the manufacturer deems appropriate. For the aforementioned Neumann mics, these tones were at octave increments between 125 Hz and 16,000 Hz for a total of 8 separate plots.

Back to table of contents.

Important Terms, Definitions, And Resources

Before we get into each polar pattern in detail, it's worth defining some of the common terms that will come up when describing each of the microphone polar patterns.

We've already defined polar pattern, top-address, side-address, on-axis/off-axis, off-axis colouration, and pressure/pressure-gradient principles. Other important terms we should define include:

• General directionality (omnidirectional, bidirectional, and unidirectional)
• Acoustic labyrinth
• Proximity effect
• Vocal plosives
• Gain-before-feedback
• Null points (axes, rings, and cones of silence)
• Lobes of sensitivity

General Directionality (Omnidirectional, Bidirectional, And Unidirectional)

There are 3 general classes of microphone directionality:

• Omnidirectional: the omnidirectional polar pattern is equally sensitive to sound from every direction.
• Bidirectional: the bidirectional polar pattern equally sensitive to sound from the front and back with a ring of silence around the sides. Also known as the figure-8 polar pattern.
• Unidirectional: unidirectional mics make up every other polar pattern, where the microphone is most sensitive in a single direction. The most popular unidirectional pattern is cardioid.

So omnidirectional and bidirectional each refers to specific polar patterns. Unidirectional is a broad term that refers to all other mic polar patterns (cardioid-type patterns and more).

Acoustic Labyrinth

What is an acoustic labyrinth, and why are they used in some microphones? An acoustic labyrinth in a microphone is a carefully designed series of ports and pathways that delay sound from reaching the rear of the mic diaphragm. Mic capsules/cartridges/bodies with properly designed acoustic labyrinths achieve unidirectionality with a single diaphragm.

True pressure (omnidirectional) and pressure-gradient (bidirectional) microphones do not have acoustic labyrinths.

To achieve unidirectionality, there must be some sort of delay/phase between the front and back of the microphone diaphragm. In practice, this is realized with acoustic labyrinths.

Typically these labyrinths are built into the mic capsules. It doesn't require much to offset the phase of sound waves.

However, a larger acoustic labyrinth is required with specialty microphone polar patterns (such as the shotgun/lobar or boundary/PZM patterns).

Shotgun/lobar microphones utilize interference tubes to achieve their polar patterns.

An interference tube is a long slotted tube that is fitted in front of the microphone diaphragm. The various slots along the length of the tube cause phase cancellation at various frequencies of sound entering the tube at off-axis angles. This allows for the extreme directionality of the shotgun/lobar pattern at the expense of side and rear lobes of sensitivity.

Boundary/PZM microphones utilize a flat boundary to achieve their polar patterns.

A flat boundary is utilized in boundary/PZM mics to eliminate any rear reflections (and subsequent phase cancellation) in the microphone. This “acoustic labyrinth” may not fit the exact definition but is used to alter (eliminate) the sound waves around the mic capsule and is worth mentioning here.

Proximity Effect

What is the proximity effect? The proximity effect is the increase in bass responsiveness of pressure-gradient microphones as a sound source gets closer to the mic diaphragm. The bass boost is due to the increased importance of the phase difference between the front and back of the diaphragm relative to the amplitude difference.

It's important to note that the proximity effect only affects pressure-gradient microphones. This effect requires that both sides of a diaphragm be exposed to the same sound waves.

Basically, there are two main factors in sound waves that cause a microphone diaphragm to move. These factors are the difference in phase and amplitude between the front and back sides of the diaphragm.

Phase refers to the amount that a sound wave has passed through its cycle.

Amplitude refers to the intensity of a sound wave.

At high frequencies (small wavelengths), the phase difference between a sound wave at the front and back of a diaphragm will be sporadic and have a great range. The phase, in this case, plays a bigger role than the amplitude in determining the pressure difference. This is true at a distance and up close.

At low frequencies (long wavelengths), the phase difference between a sound wave at the front and back of a diaphragm will be small. So phase is not the primary differentiator in the pressure difference between the front and back of a diaphragm. Instead, at low frequencies, the amplitude of the wave is more important.

The inverse-square law states that a sound wave loses half its intensity (amplitude) for every doubling of distance.

So at a fair distance from the microphone, low frequencies are fine. The distance between the front and back of the diaphragm could be considered negligible compared to the distance from the sound source to the front of the diaphragm.

However, as we get closer, things change. Let's say, for simplicity, that we're incredibly close to the microphone at a distance equal to the distance between the front and back of the diaphragm.

The inverse-square law states that the amplitude at the rear of the diaphragm will have half of that at the front of the diaphragm. This is a massive difference and will cause great diaphragm movement at low frequencies. This causes the bass boost known as the proximity effect.

Remember that the proximity effect only happens in microphones that have both sides of their diaphragms exposed to the same sound waves. Therefore, pressure microphones are immune to the proximity effect!

For a complete explanation of the microphone proximity effect, check out my article What Is Microphone Proximity Effect And What Causes It?

Vocal Plosives

What are vocal plosives, and how do they affect microphones? Plosives are strong blasts of wind energy that come from the mouth of a speaker. Plosives happen on certain consonant sounds when a part of the mouth gets closed (lips, tongue and teeth, or the back of mouth). English plosives happen on T’s, P’s, B’s, D’s, K’s, and G’s.

Vocal plosives are heard as “mic pops” and are quite unpleasant. Some microphone polar patterns are better suited to handle these blasts of wind energy that come from our mouths.

For a complete explanation of vocal plosives and how they affect microphones, check out my article Top 10 Tips For Eliminating Microphone Pops And Plosives.

Gain-Before-Feedback

What is gain-before-feedback? Gain-before-feedback is the amount of gain we are able to apply to a microphone in a sound reinforcement situation before that mic starts to feedback with its loudspeakers or monitors. Gain-before-feedback is dependent on several factors, including the physical space and mic placement.

Understanding how to get the most gain-before-feedback is an essential skill for live sound reinforcement. The audience needs to be able to hear the performance accurately. At the same time, one instance of microphone feedback has the potential to tarnish an entire show.

Gain-before-feedback has to do with the placement of microphones in relation to loudspeakers. Some microphone polar patterns have null points that allow them more gain-before-feedback when positioned correctly.

To read more about microphone feedback, check out 12 Methods To Prevent & Elminate Microphone/Audio Feedback.

Null Points (Axes, Rings, And Cones Of Silence)

What is a microphone polar pattern null point? A directional mic’s null point is an angle from its axis in which it is theoretically insensitive to sound. Note that the directionality of mics is 3-D, and so if a polar pattern has a pair of null points, it really has a “cone” or “ring” of rejection rather than a “null point.”

Lobes Of Sensitivity

What are microphone lobes of sensitivity? Microphone lobes refer to the sensitive areas of a polar pattern. Most directional microphones have lobes of sensitivity along with null points (rings or cones of insensitivity). Lobes often refer to the rear sensitivity of lobar, hypercardioid, and supercardioid polar patterns.

Okay, now it's time for the good stuff! Let's get into each polar pattern in greater detail.

Omnidirectional Polar Pattern

What is the omnidirectional microphone polar pattern? A microphone with an omnidirectional polar pattern, in theory, is equally sensitive to sound in all directions. It is the polar pattern of the pressure principle.

Key Points About The Omnidirectional Polar Pattern

1. Works on the pressure principle
2. Sensitive to sounds in all directions
3. Resistant to vocal plosives
4. Exhibits no proximity effect
5. Low gain-before-feedback
6. Least colouration to the sound

1. Works On The Pressure Principle

Omnidirectional patterns typically work on the pressure principle. In fact, single diaphragm omnidirectional microphones provide the truest form of the pressure principle, where only the front sides of their diaphragms are exposed to external sound pressure. The rear sides of their diaphragms are closed off (in a tiny chamber at constant pressure).

Note that the omnidirectional option on many multi-pattern microphones is achieved by back-to-back cardioid capsules/diaphragms and, therefore, works on the pressure-gradient principle. These omni patterns are generally not as “truly omnidirectional” as their single-diaphragm pressure principle counterparts.

2. Sensitive To Sounds In All Directions

Omnidirectional microphones, in theory, are equally sensitive to sound from every direction. This generally holds true for lower frequencies.

However, due to the nature of high-frequency short-wavelength sounds and the physical space of the microphone body, most omnidirectional microphones become somewhat unidirectional at high frequencies.

For that reason, small omnidirectional lavalier/lapel microphones often yield the best “ideal omnidirectional” patterns.

3. Resistant To Vocal Plosives

Because omnidirectional microphones work on the pressure principle, they are very resistant to the overloading of vocal plosives.

4. Exhibits No Proximity Effect

Because omnidirectional microphones work on the pressure principle, they exhibit absolutely no proximity effect.

5. Low Gain-Before-Feedback

Since omnidirectional microphones are equally sensitive to sounds from all directions, they have no null points. Therefore, placing them around loudspeakers will be challenging.

The relatively poor gain-before-feedback of omnidirectional microphones makes them less-than-ideal for live sound reinforcement applications.

6. Least Colouration To The Sound

When trying to record the most natural sound, especially at a distance from the sound source, omnidirectional microphones are an excellent choice.

Their relative lack of off-axis colouration allows them to capture sounds from all angles accurately and naturally.

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

Examples Of Omnidirectional Microphones

• Neumann M 50 and the Wunder Audio CM50 S clone
• DPA d:screet CORE 6060
• Neumann KM 183

Neumann M 50 And The Wunder Audio CM50 S Clone

The Neumann M 50 is featured in the following My New Microphone articles:
• 50 Best Microphones Of All Time (With Alternate Versions & Clones)
• Top 12 Best Vintage Microphones (And Their Best Clones)

The legendary Neumann M 50 (and its best clone, the Wunder Audio CM50 S), are omnidirectional side-address microphones. Though they resemble many large-diaphragm condensers, they are actually small-diaphragm condensers.

We see that, even though the M 50 is an omnidirectional microphone, its polar pattern begins to resemble a more directional cardioid-type pattern above 10,000 Hz.

The M 50 has been a standard microphone for stereo miking techniques and orchestral recordings since its introduction in 1951.

DPA d:screet CORE 6060

The DPA d:screet CORE 6060 is a lavalier/lapel microphone that is top-address.

DPA does not provide a polar response graph for its d:screet CORE 6060. Because the microphone body is so small, the polar response is practically an ideal omnidirectional pattern.

Neumann KM 183

The Neumann KM 183 is the omnidirectional mic in the KM 180 line of microphones (which also hosts the cardioid KM 184).

The KM 183 is a beautifully consistent omnidirectional small-diaphragm top-address condenser microphone. As consistent as it is, though, we still see that it becomes quite directional above 16 kHz.

Back to table of contents.

Bidirectional (Figure-8) Polar Pattern

What is the bidirectional microphone polar pattern? The bidirectional (figure-8) microphone polar pattern is equally sensitive to sounds from the front and the back with a ring of silence at its sides. Bidirectional mics are the truest form of pressure-gradient mics and exhibit the most proximity effect. Nearly all ribbon mics are bidirectional.

Bidirectional is also known as “figure-8.”

Key Points About The Bidirectional Polar Pattern

1. Works on the pressure-gradient principle
2. Equally sensitive to sounds from the front and back
3. Ring of silence (null points) around the sides (90° & 270°)
4. Sensitive to vocal plosives
5. Exhibits the most proximity effect
6. Requires a side-address mic set up
7. Standard pattern for ribbon microphones

1. Works On The Pressure-Gradient Principle

The bidirectional microphone polar pattern is the truest form of the pressure-gradient principle, where both sides of the diaphragm are equally exposed to exterior sound pressure.

The bidirectional options in most multi-pattern microphones are also achieved with the pressure-gradient principle. However, the bidirectional option is typically created by two back-to-back cardioid capsules/diaphragms set at equal amplitudes and opposite polarity.

2. Equally Sensitive To Sounds From The Front And Back

The bidirectional microphone polar pattern means the mic is equally sensitive to the front and back sounds with symmetrical off-axis coloration.

The only difference between the front and back is the polarity in which the sound affects the microphone. The front of the diaphragm reacts to sound with positive polarity, while the rear of the diaphragm reacts to sound with negative polarity.

3. Ring Of Silence (Null Points) Around The Sides (90° & 270°)

True bidirectional polar patterns have null points at the sides (90° and 270°). In 3D, this results in a “cone of silence” in which sounds emanating directly from the sides of the microphone are completely rejected.

This is because the sound waves reaching the bidirectional microphone from the side will simultaneously hit both sides of the diaphragm. Since the sound wave will hit each side of the diaphragm with equal force, the diaphragm will not move, and no mic signal will be produced.

4. Sensitive To Vocal Plosives

Because the bidirectional polar pattern acts on the pressure-gradient principle, bidirectional mics are prone to overloading due to vocal plosives.

5. Exhibits The Most Proximity Effect

Since both sides are evenly open to external sound pressure, there's no acoustic labyrinth impeding sound waves from reaching the rear side of the diaphragm.

Generally speaking, this means that the distance between the front and back of a bidirectional microphone is less than unidirectional mics with acoustic labyrinths. Therefore, the proximity effect would be the most present in bidirectional microphones.

Note that this isn't necessarily the case if the bidirectional mic has a long path between the front and back of its diaphragm. However, this generality certainly holds true most of the time.

6. Requires A Side-Address Mic Setup

It's physically impossible to achieve a true bidirectional polar pattern within a top-address microphone.

Side-address mics allow for symmetry and equal exposure of the two sides of a bidirectional capsule/cartridge/element.

7. Standard Pattern For Ribbon Microphones

The standard ribbon element is designed in a side-address setup with both sides of the ribbon diaphragm exposed to external sound pressure.

For this reason, the vast majority of ribbon microphones (though certainly not all) will have a bidirectional polar pattern.

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

Examples Of Bidirectional Microphones

• Royer R-121
• AEA R84

Royer R-121

The Royer R-121 is one of the world's most famous ribbon microphones. We see above that its polar response is incredibly consistent along its frequency response, though it does become slightly more directional at higher frequencies.

The Royer R-121, like nearly all ribbon mics (and certainly all bidirectional mics), is a side-address.

AEA R84

The AEA R84 is the Audio Engineering Associates' clone of the legendary (but discontinued) RCA 44-BX. As we see above, the side-address bidirectional polar pattern is solid through the microphone's frequency response.

The original RCA 44-BX is featured in the following My New Microphone articles:
• 50 Best Microphones Of All Time (With Alternate Versions & Clones)
• Top 12 Best Vintage Microphones (And Their Best Clones)

Back to table of contents.

Cardioid Polar Pattern

What is the cardioid microphone polar pattern? The ideal cardioid microphone polar pattern is a directional pattern that is most sensitive in the mic’s on-axis direction with a null point in the exact opposite direction, and a gradual attenuation in between that reaches -6 dB at 90° and 270°. The cardioid pattern is the most common polar pattern.

Cardioid is also known as “kidney” or “heart” and is often what people are referring to when using the term “unidirectional.”

Key Points About The Cardioid Polar Pattern

1. Works on the pressure-gradient principle
2. Most commonly used polar pattern
3. Very popular for vocal microphones
4. Used to achieve various other patterns in multi-pattern mics
5. Most sensitive to sounds in a single direction (on-axis 0°)
6. Null point to the rear (180°)
7. Roughly 6 dB less sensitive at the sides (90° & 270°)
8. Sensitive to vocal plosives
9. Exhibits proximity effect
10. Excellent gain-before-feedback
11. 1:1 ratio of an omnidirectional and a bidirectional polar pattern

1. Works On The Pressure-Gradient Principle

The cardioid polar pattern works on the pressure-gradient principle, where both sides of the diaphragm are exposed to external sound pressure.

However, with the cardioid pattern (as with all unidirectional polar patterns), the rear of the diaphragm is surrounded by an acoustic labyrinth. This series of well-designed ports and acoustic dampening introduces time delay and even decreased amplitude at the rear side of the diaphragm.

The carefully tuned offset provided by the acoustic labyrinth is responsible for the specific shape of the cardioid polar pattern.

2. Most Commonly Used Polar Pattern

From vocal mics to instrument mics. From the stage to the studio to the broadcasting room. Whether it's a large/small-diaphragm, a lavalier, condenser/dynamic, cardioid mics are the most popular and commonly used microphone on Earth.

3. Very Popular For Vocal Microphones

Whether it's a studio session, a live performance, or even a news interview on the street, cardioid microphones are the go-to for recording/reinforcing vocals (both singing and speaking).

4. Used To Achieve Various Other Patterns In Multi-Pattern Mics

The most common design type for multi-pattern microphones involved 2 back-to-back cardioid diaphragms.

Most other polar patterns are achievable by altering the polarity and amplitude of the mic signal generated with each diaphragm.

5. Most Sensitive To Sounds In A Single Direction (On-Axis 0°)

As with all unidirectional microphones, the cardioid polar pattern is the most sensitive in a single direction (the 0° point on its polar response graph).

6. Null Point To The Rear (180°)

The cardioid polar pattern is best known for its rear-facing null point. This provides maximum rejection in the opposite direction of where a cardioid mic is pointing.

This 180° null point is highly beneficial for gain-before-feedback and positioning the microphone in live reinforcement situations.

7. Roughly 6 dB Less Sensitive At The Sides (90° & 270°)

The cardioid polar pattern gradually decreases in sensitivity from its 0° point (on-axis) to its 180° point (completely off-axis).

At its sides (90° and 270°), the ideal cardioid polar pattern is 6 decibels less sensitive to sound than it is to sound on-axis (0°). This means the cardioid pattern is fairly rejecting of sound waves to the side (6 dB difference is means half the sound intensity).

8. Sensitive To Vocal Plosives

Because the cardioid polar pattern works on the pressure-gradient principle, cardioid mics are prone to the overloading caused by vocal plosives.

9. Exhibits Proximity Effect

Although not as susceptible as a typical bidirectional microphone, cardioid mics do exhibit the proximity effect. This is due to the nature of cardioids working on the pressure-gradient principle.

10. Excellent Gain-Before-Feedback

Cardioid microphones have excellent gain-before-feedback and are the go-to microphone polar pattern for live sound reinforcement.

The best example of this is a singer during a live performance.

When the singer is stationary in from of their monitor, a cardioid mic can easily be positioned to point on-axis toward the singer's mouth while simultaneously pointing away from the monitor. The rear null point of the cardioid mic will effectively reject the sound from the monitor while picking up a strong signal from the singer.

If the singer is moving, so long as they do not point the microphone at a monitor or other loudspeaker, the cardioid microphone should yield the best gain-before-feedback still.

11. 1:1 Ratio Of An Omnidirectional And A Bidirectional Polar Pattern

When looking at unidirectional microphones, it's interesting to view them as superpositions of the standard omnidirectional and bidirectional patterns.

As previously mentioned, the cardioid polar pattern is essentially a 1:1 ratio of an omnidirectional pattern combined with a bidirectional pattern.

For a more focused article on the cardioid polar pattern, please check out my article What Is A Cardioid Microphone? (Polar Pattern + Mic Examples).

Examples Of Cardioid Microphones

• Shure SM57 and SM58
• Neumann KM 184
• Rode NT1-A

Shure SM57 And SM58

The Shure SM57 and SM58 are likely the most popular instrument and live vocal microphone on the planet, respectively. These top-address cardioid microphones are absolute beasts and deserve their praise and popularity.

With both these microphones, at 125 Hz and below, we can see that they act more like subcardioid mics. From 500 Hz – 2,000 Hz, they are both near the ideal cardioid polar pattern. At 4,000 Hz and above, they both begin taking on a more supercardioid/hypercardioid pattern with the rear lobe of sensitivity.

Again, these changes in polar pattern are to be expected since microphones become more directional at higher frequencies and less directional at lower frequencies.

Neumann KM 184

The Neumann KM 184 is getting a lot of attention in this article! This top-address small-diaphragm condenser has a beautifully consistent cardioid polar pattern.

Rode NT1-A

The Rode NT1-A is a side-address large-diaphragm condenser microphone with a cardioid polar pattern.

The Rode NT1-A has a peculiar polar response graph. It tells us that the microphone is actually more directional at 500 Hz than at 4,000 Hz. This is against the generality that microphones become more directional at higher frequencies.

Back to table of contents.

Supercardioid Polar Pattern

What is the supercardioid microphone polar pattern? The supercardioid polar pattern is a highly directional microphone polar pattern. Ideal supercardioids are a 5:3 ratio of bidirectional to omnidirectional patterns. They are more directional than cardioids but have a rear lobe of sensitivity with null points at 127° and 233° (cone of silence).

Key Points About The Supercardioid Polar Pattern

1. Works on the pressure-gradient principle
2. Similar to hypercardioid
3. Very popular in film
4. Unidirectional (most sensitive to sounds in a single direction – on-axis 0°)
5. Rear cone of silence: Null points to the rear (127° & 233°)
6. Rear lobe of sensitivity (typically -10 dB less sensitive than on-axis)
7. Roughly 10 dB less sensitive at the sides (90° & 270°)
8. Sensitive to vocal plosives
9. Exhibits proximity effect
10. Often the base pattern for lobar/shotgun patterns
11. 5:3 ratio of an omnidirectional and a bidirectional polar pattern

1. Works On The Pressure-Gradient Principle

The supercardioid polar pattern works on the pressure-gradient principle, where both sides of the diaphragm are exposed to external sound pressure.

However, with the supercardioid pattern (as with all unidirectional polar patterns), the rear of the diaphragm is surrounded by an acoustic labyrinth. This series of well-designed ports and acoustic dampening introduces time delay and even decreased amplitude at the rear side of the diaphragm.

The carefully tuned offset provided by the acoustic labyrinth is responsible for the specific shape of the supercardioid polar pattern.

2. Similar To Hypercardioid

Supercardioid and hypercardioid polar patterns are similar and often confused. They are both unidirectional patterns with 2 null points (a cone of silence) and a rear lobe of sensitivity.

• Supercardioid is slightly less directional than hypercardioid.
• Supercardioid has a smaller rear lobe of sensitivity than hypercardioid.

3. Very Popular In Film

The focused directionality of supercardioid microphones makes them popular choices in video production as both boom mics and camera mics. This is especially true when a supercardioid capsule is combined with an interference tube to make a lobar/shotgun polar pattern.

4. Unidirectional (Most Sensitive To Sounds In A Single Direction – On-Axis 0°)

As with all unidirectional microphones, the supercardioid polar pattern is the most sensitive in a single direction (the 0° point on its polar response graph).

5. Rear Cone Of Silence: Null Points To The Rear (127° & 233°)

The ideal supercardioid polar pattern has null points at 127° and 233°. This means there is effectively a cone of silence (sound rejection) to the rear of the microphone.

This makes supercardioids a good choice for dual foldback monitor setups in live sound performance (when these monitors are set up at 127° and 233° from the supercardioid's on-axis line.

6. Rear Lobe Of Sensitivity (Typically -10 dB Less Sensitive Than On-Axis)

The supercardioid polar pattern has a characteristic rear lobe of sensitivity that is typically 10 decibels less sensitive than its on-axis response. This is still a fair bit of rejection, but the microphone will still pick up sound from its rear.

7. Roughly 10 dB Less Sensitive At The Sides (90° & 270°)

A 10-decibel difference in sensitivity between the 0° on-axis response and the side responses of the supercardioid polar pattern is part of the reason why this pattern is so highly directional.

8. Sensitive To Vocal Plosives

Because the supercardioid polar pattern works on the pressure-gradient principle, supercardioid mics are prone to the overloading caused by vocal plosives.

9. Exhibits Proximity Effect

Although not as susceptible as a typical bidirectional microphone, supercardioid mics do exhibit the proximity effect. This is due to the nature of supercardioids working on the pressure-gradient principle.

10. Often The Base Pattern For Lobar/Shotgun Patterns

The high directionality of the supercardioid polar pattern is often enhanced with an interference tube in order to achieve the lobar polar pattern, which is responsible for the extreme directionality of shotgun microphones.

11. 5:3 Ratio Of An Omnidirectional And A Bidirectional Polar Pattern

The supercardioid polar pattern is essentially a 5:3 ratio of an omnidirectional pattern combined with a bidirectional pattern.

For a more focused article on the supercardioid polar pattern, please check out my article What Is A Supercardioid Microphone? (Polar Pattern + Mic Examples).

Examples Of Supercardioid Microphones

• DPA d:dicate 4018A
• Sennheiser e906

DPA d:dicate 4018A

The DPA 4018A is a top-address small-diaphragm condenser microphone. By its polar response diagram, you'll see that its polar pattern is very consistent throughout its entire frequency response.

As per usual, though, there's an increase in directionality in the upper-frequency range (16 kHz).

Sennheiser e906

The Sennheiser e906 is a side-address moving-coil dynamic microphone with a supercardioid polar pattern.

Once again, the polar response is consistent until the high-end frequencies. Because of the relatively poor upper-frequency response of moving-coil dynamics (compared to condenser mics), the high-end polar response is particularly odd in the e906.

Back to table of contents.

Hypercardioid Polar Pattern

What is the hypercardioid microphone polar pattern? The hypercardioid polar pattern is a highly directional mic polar pattern. Ideal hypercardioids are a 3:1 ratio of bidirectional to omni patterns. They are more directional than cardioids and supercardioids with a larger rear lobe of sensitivity and null points at 110° and 250°.

Key Points About The Hypercardioid Polar Pattern

1. Works on the pressure-gradient principle
2. Similar to supercardioid
3. Very popular in film
4. Unidirectional (most sensitive to sounds in a single direction – on-axis 0°)
5. Rear cone of silence: Null points to the rear (110° & 250°)
6. Rear lobe of sensitivity (typically -6 dB less sensitive than on-axis)
7. Roughly 12 dB less sensitive at the sides (90° & 270°)
8. Sensitive to vocal plosives
9. Exhibits proximity effect
10. Often the base pattern for lobar/shotgun patterns
11. 3:1 ratio of an omnidirectional and a bidirectional polar pattern

1. Works On The Pressure-Gradient Principle

The hypercardioid polar pattern works on the pressure-gradient principle, where both sides of the diaphragm are exposed to external sound pressure.

However, with the hypercardioid pattern (as with all unidirectional polar patterns), the rear of the diaphragm is surrounded by an acoustic labyrinth. This series of well-designed ports and acoustic dampening introduces time delay and even decreased amplitude at the rear side of the diaphragm.

The carefully tuned offset provided by the acoustic labyrinth is responsible for the specific shape of the hypercardioid polar pattern.

2. Similar To Supercardioid

Hypercardioid and supercardioid polar patterns are similar and often confused. They are both unidirectional patterns with 2 null points (a cone of silence) and a rear lobe of sensitivity.

• Hypercardioid is slightly more directional than supercardioid.
• Hypercardioid has a larger rear lobe of sensitivity than supercardioid.

3. Very Popular In Film

The focused directionality of hypercardioid microphones makes them popular choices in video production as both boom mics and camera mics. This is especially true when a hypercardioid capsule is combined with an interference tube to make a lobar/shotgun polar pattern.

4. Unidirectional (Most Sensitive To Sounds In A Single Direction – On-Axis 0°)

As with all unidirectional microphones, the hypercardioid polar pattern is the most sensitive in a single direction (the 0° point on its polar response graph).

5. Rear Cone Of Silence: Null Points To The Rear (110° & 250°)

The ideal hypercardioid polar pattern has null points at 110° and 250°. This means there is effectively a cone of silence (sound rejection) to the rear of the microphone.

This makes hypercardioids a good choice for dual foldback monitor setups in live sound performance (when these monitors are set up at 110° and 250° from the hypercardioid's on-axis line.

6. Rear Lobe Of Sensitivity (Typically -6 dB Less Sensitive Than On-Axis)

The hypercardioid polar pattern has a characteristic rear lobe of sensitivity that is typically 6 decibels less sensitive than its on-axis response. This is still a fair bit of rejection, but the microphone will still pick up sound from its rear.

7. Roughly 12 dB Less Sensitive At The Sides (90° & 270°)

A 12-decibel difference in sensitivity between the 0° on-axis response and the side responses of the hypercardioid polar pattern is part of the reason why this pattern is so highly directional.

8. Sensitive To Vocal Plosives

Because the hypercardioid polar pattern works on the pressure-gradient principle, hypercardioid mics are prone to the overloading caused by vocal plosives.

9. Exhibits Proximity Effect

Although not as susceptible as a typical bidirectional microphone, hypercardioid mics do exhibit the proximity effect. This is due to the nature of hypercardioids working on the pressure-gradient principle.

10. Often The Base Pattern For Lobar/Shotgun Patterns

The high directionality of the hypercardioid polar pattern is often enhanced with an interference tube in order to achieve the lobar polar pattern, which is responsible for the extreme directionality of shotgun microphones.

11. 3:1 Ratio Of An Omnidirectional And A Bidirectional Polar Pattern

The hypercardioid polar pattern is essentially a 3:1 ratio of an omnidirectional pattern combined with a bidirectional pattern.

For a more focused article on the hypercardioid polar pattern, please check out my article What Is A Hypercardioid Microphone? (Polar Pattern + Mic Examples).

Examples Of Hypercardioid Microphones

• Audix D4
• Beyerdynamic M 160

Audix D4

The Audix D4 is a top-address large-diaphragm dynamic microphone.

Although the Audix D4 looks as if it has a subcardioid pattern at first glance, upon further inspection, we see that it is, in fact, a hypercardioid microphone. However, as expected, the D4 becomes more omnidirectional at lower frequencies (below 500 Hz).

Audix simply puts a great amount of detail into the above polar response graphs (0 to -36 dB in its circles).

Beyerdynamic M 160

The Beyerdynamic M 160 is a unique ribbon microphone. Not only does it feature a double ribbon, but it is also a top-address mic with a hypercardioid polar pattern.

The polar response graph of the M 160 is relatively difficult to read, but if we look closely, we can see the pattern is fairly consistent. We also see that the M 160 defies the norm and actually spreads out at its higher frequencies (8,000 Hz).

Back to table of contents.

Subcardioid/Wide Cardioid Polar Pattern

What is the subcardioid/wide cardioid microphone polar pattern? The subcardioid/wide cardioid polar pattern is a broad, unidirectional pattern. Subcardioids have no null points and a 3-10 dB drop in sensitivity to the rear. They can be thought of as a superposition of omnidirectional and cardioid patterns.

Subcardioid is also known as “wide cardioid.”

Key Points About The Subcardioid/Wide Cardioid Polar Pattern

1. Works on the pressure-gradient principle
2. Rare as a primary pattern
3. Unidirectional (most sensitive to sounds in a single direction – on-axis 0°)
4. No null points
5. Roughly 3 dB less sensitive at the sides (90° & 270°)
6. Roughly 10 dB less sensitive at the rear (180°)
7. Sensitive to vocal plosives
8. Exhibits proximity effect
9. 7:3 ratio of an omnidirectional and a bidirectional polar pattern

1. Works On The Pressure-Gradient Principle

The subcardioid/wide cardioid polar pattern works on the pressure-gradient principle, where both sides of the diaphragm are exposed to external sound pressure.

However, with the subcardioid pattern (as with all unidirectional polar patterns), the rear of the diaphragm is surrounded by an acoustic labyrinth. This series of well-designed ports and acoustic dampening introduces time delay and even decreased amplitude at the rear side of the diaphragm.

The carefully tuned offset provided by the acoustic labyrinth is responsible for the specific shape of the wide cardioid polar pattern.

2. Rare As A Primary Pattern

There aren't very many mics that are marketed as subcardioid/wide cardioid.

However, because microphones become more directional at higher frequencies and less directional at lower frequencies, we'll often see the following:

• Omnidirectional microphones begin exhibiting a subcardioid pattern at higher frequencies.
• Cardioid microphones begin exhibiting a subcardioid pattern at lower frequencies.

There are, of course, subcardioid or wide cardioid microphones on the market. They're just not overly popular.

A wide cardioid pattern is an option on some multi-pattern microphones—notably those with a CK-12 capsule (or capsules based on the CK-12 design).

3. Unidirectional (Most Sensitive To Sounds In A Single Direction – On-Axis 0°)

As with all unidirectional microphones, the subcardioid/wide cardioid polar pattern is the most sensitive in a single direction (the 0° point on its polar response graph).

4. No Null Points

The ideal subcardioid polar pattern has no null points.

5. Roughly 3 dB Less Sensitive At The Sides (90° & 270°)

The wide cardioid polar pattern is fairly omnidirectional, with only a 3 dB difference between the on-axis and side responses.

6. Roughly 10 dB Less Sensitive At The Rear (180°)

With a 10 dB difference between the on-axis and rear responses, the wide cardioid polar pattern is fairly effective at rejecting rear sound sources.

This yields some isolation from rear positioned sources while maintaining a natural capture of the sound sources in front of the subcardioid mic.

7. Sensitive To Vocal Plosives

Because the subcardioid polar pattern works on the pressure-gradient principle, wide cardioid mics are prone to the overloading caused by vocal plosives.

8. Exhibits Proximity Effect

Although not as susceptible as a typical bidirectional microphone, subcardioid mics do exhibit the proximity effect. This is due to the nature of wide cardioids working on the pressure-gradient principle.

9. 7:3 Ratio Of An Omnidirectional And A Bidirectional Polar Pattern

The subcardioid polar pattern is essentially a 7:3 ratio of an omnidirectional pattern combined with a bidirectional pattern.

For a more focused article on the subcardioid/wide cardioid polar pattern, please check out my article What Is A Subcardioid/Wide Cardioid Microphone? (With Mic Examples).

Examples Of Subcardioid/Wide Cardioid Microphones

• Microtech Gefell M 950
• Schoeps MK 21 / CMC 6

Microtech Gefell M 950

The Microtech Gefell M 950 is a side-address large-diaphragm condenser with a subcardioid pattern.

As we can see above, the subcardioid polar pattern holds true across most of the microphone's frequency response. It becomes nearly supercardioid by 8 kHz and extremely directional at 16 kHz.

Schoeps MK 21 / CMC 6

The Schoeps MK 21 is a small-diaphragm condenser capsule with a wide cardioid polar pattern. It is a module capsule that is part of Schoeps' Colette series. This top-address capsule sounds great on the CMC 6 microphone amplifier.

As we can see above, the subcardioid polar pattern holds true across the entirety of the microphone's frequency response. Schoeps is known for its incredibly consistent microphones, and the MK 21 is no exception.

Back to the table of contents.

Lobar/Shotgun Polar Pattern

What is the lobar/shotgun microphone polar pattern? The lobar/shotgun polar pattern is the extremely directional polar pattern found in shotgun mics. Lobar patterns are often based on hyper or supercardioid patterns and require interference tubes to achieve their directionality. They have side and rear lobes of sensitivity.

Key Points About The Lobar/Shotgun Polar Pattern

1. Only achievable by physical acoustic labyrinth (interference tube)
2. Extension of supercardioid/hypercardioid patterns
3. Works on the pressure-gradient principle
4. Very common in film and television (on camera and boom poles)
5. Unidirectional (most sensitive to sounds in a single direction – on-axis 0°)
6. Most directional pattern
7. Side and rear lobes of sensitivity
8. Roughly 18 dB less sensitive at the sides (90° & 270°)
9. Roughly 10 dB less sensitive at the rear (180°)
10. Null points at 60°, 120°, 240°, and 300° (cones of silence)
11. Sensitive to vocal plosives
12. Exhibits proximity effect

1. Only Achievable By Physical Acoustic Labyrinth (Interference Tube)

You'll notice that shotgun microphones are all relatively long and skinny. Shotgun mics are unlike most pencil microphones, with capsules near the end of the microphone and their electronics in the body. Instead, shotgun mics have capsules somewhere in the middle of the overall mic body and long interference tubes extending them.

An interference tube is a long slotted tube fitted in front of the shotgun microphone's diaphragm. The various slots along the tube cause phase cancellation in the sound waves that enter the tube at off-axis angles.

Basically, the interference tube drastically increases the microphone's directionality by rejecting most sounds that are not at a narrow angle from the mic's on-axis line. This is the only way to achieve a lobar pattern.

2. Extension Of Supercardioid/Hypercardioid Patterns

The lobar pattern is simply a physical upgrade in directionality to the already focused supercardioid and hypercardioid patterns.

3. Works On The Pressure-Gradient Principle

Because the lobar/shotgun polar pattern is based on unidirectional (typically supercardioid or hypercardioid) polar patterns, it, by default, works on the pressure-gradient principle.

4. Very Common In Film And Television (On Camera And Boom Poles)

Because of the extreme directionality (and therefore the rejection of off-axis sounds), the lobar polar pattern has found its calling in film. It is heavily used as a boom microphone and as an on-camera mic.

5. Unidirectional (Most Sensitive To Sounds In A Single Direction – On-Axis 0°)

As with all unidirectional microphones, the lobar/shotgun polar pattern is the most sensitive in a single direction (the 0° point on its polar response graph).

6. Most Directional Pattern

As previously mentioned, the lobar/shotgun pattern is the most directional polar pattern.

7. Side And Rear Lobes Of Sensitivity

The characteristic lobar polar pattern has a strong and narrow on-axis response along with smaller side and rear lobes of sensitivity.

8. Roughly 18 dB Less Sensitive At The Sides (90° & 270°)

One consequence of the interference tube is that it generally leaves its microphone with small side lobes of sensitivity. However, an 18-decibel difference between on-axis and side sound pick up means the side sensitivity is practically negligible.

9. Roughly 10 dB Less Sensitive At The Rear (180°)

Because the lobar pattern is typically based on supercardioid and hypercardioid capsules, there will be rear lobes of sensitivity.

10. Null Points At 60°, 120°, 240°, And 300° (Cones Of Silence)

Generally speaking, the ideal lobar pattern will have 4 lobes of sensitivity (including the critical on-axis lobe) along with 4 null points (at 60°, 120°, 240°, and 300°).

11. Sensitive To Vocal Plosives

Because the lobar polar pattern works on the pressure-gradient principle, shotgun mics are prone to the overloading caused by vocal plosives.

12. Exhibits Proximity Effect

Although not as susceptible as a typical bidirectional microphone, the lobar polar pattern does exhibit the proximity effect. This is due to the nature of shotgun mics working on the pressure-gradient principle.

For a more focused article on the lobar/shotgun polar pattern, please check out my article The Lobar/Shotgun Microphone Polar Pattern (With Mic Examples).

Examples Of Shotgun/Lobar Microphones

• Sennheiser MKH 60
• Schoeps CMIT 5U

Sennheiser MKH 60 (Discontinued)

The Sennheiser MKH 60 is, naturally, a top-address shotgun microphone.

As we see, the lobar polar pattern's side lobes only really show up in the higher frequencies (8,000 Hz and above). As we expect, the polar pattern shows a rear lobe of sensitivity and the null points tell us this microphone is based on a supercardioid pattern.

Schoeps CMIT 5U

The Schoeps CMIT 5U is a top-address shotgun microphone.

This microphone shows extreme directionality but no side lobes to explicitly tell us it's a lobar pattern. However, we see that the polar pattern shows a rear lobe of sensitivity, and the null points tell us this microphone is based on a hypercardioid pattern.

Back to the table of contents.

Boundary/PZM Polar Pattern

What is the boundary/PZM microphone polar pattern? The boundary/PZM microphone polar pattern is a sort of hemispherical pattern. It requires a flat surface (boundary) to eliminate rear reflections and work properly. This specialized pattern can have a capsule with any standard polar pattern.

Boundary mics are also known as “PZM (pressure zone microphones).”

Note that most boundary/PZM microphone manufacturers do not show polar response graphs. However, a typical boundary/PZM mic polar looks like the following:

Key Points About The Boundary/PZM Polar Pattern

1. Only achievable by physical acoustic labyrinth (flat surface)
2. Works on either the pressure or pressure-gradient principle (hemispherical or half-cardioid)
3. Very common in studio and stage
4. Complete phase coherence when positioned at a boundary in an acoustic space

1. Only Achievable By Physical Acoustic Labyrinth (Flat Surface)

The hemispherical nature of the boundary/PZM polar pattern is only achievable by a set boundary that is incredibly close to the microphone diaphragm.

The incredibly close boundary effectively eliminates the rear reflections that would otherwise cause phase issues with a microphone positioned close to a surface. This allows the boundary/PZM microphone a basically hemispherical pattern.

2. Works On Either The Pressure Or Pressure-Gradient Principle (Hemispherical Or Half-Cardioid)

Because the boundary/PZM polar pattern's base polar response could be omnidirectional or unidirectional, these mics could work on either the pressure principle or the pressure-gradient principle, respectively.

3. Very Common In Studio And Stage

Boundary/PZM find their niche as room mics in the studio and in live sound reinforcement.

4. Complete Phase Coherence When Positioned At A Boundary In An Acoustic Space

As part of their design, pressure zone microphones have no phase issues when placed at physical boundaries. This is explained by their hemispherical polar pattern.

For a more focused article on the boundary/PZM polar pattern, please check out my article The Hemispherical Boundary Microphone/PZM Polar Pattern.

Examples Of Boundary/PZM Microphones

• AKG C 547 BL
• Audio-Technica U851R

AKG C 547 BL

The AKG C 547 BL actually features a hypercardioid capsule. The resulting PZM polar pattern is designed to reject some sound from the “rear” of the microphone while remaining sensitive to the front of the microphone.

This pattern makes the AKG C 547 BL an excellent choice for tricky live sound reinforcement situations with a lot of extraneous noise.

Audio-Technica U851R

The Audio-Technica U851R yields a more traditional hemispherical polar pattern. Note that it is slightly less sensitive to sounds at the side.

Back to the table of contents.

So that wraps up the main polar patterns we'll encounter in microphones. Now let's talk about combining these polar patterns in interesting ways with multi-pattern, infinitely variable, stereo, and ambisonic microphones!

Multi-Pattern Microphones

What is a multi-pattern microphone, and which polar patterns do they have? Multi-pattern microphones typically have dual-diaphragm capsules but may have more capsules and diaphragms. In theory, they may achieve any polar pattern by combining their capsule/diaphragm signals in varying amplitudes and phases.

Key Points About Multi-Pattern Microphone Polar Pattern

1. Most commonly designed into side-address large-diaphragm condenser microphones
2. Typically made from back-to-back cardioid condenser microphone diaphragms/capsules
3. Various polar patterns are achievable by combining the signals of 2 or more capsules with varying amplitudes and phases
4. Can be achieved via physical means (adjustable acoustic labyrinth)
5. Will typically have cardioid, bidirectional, and omnidirectional options. Some have only 2 options, while others have many more

1. Most Commonly Designed Into Side-Address Large-Diaphragm Condenser Microphones

The vast majority of multi-pattern microphones are large-diaphragm side-address condenser mics.

2. Typically Made From Back-To-Back Cardioid Condenser Microphone Diaphragms/Capsules

Within these mics, there's generally a dual-diaphragm capsule or two back-to-back capsules. Each of these types typically has a cardioid pattern.

3. Various Polar Patterns Are Achievable By Combining The Signals Of 2 Or More Capsules With Varying Amplitudes And Phases

• Cardioid option could be a single diaphragm's signal with double the amplitude.
• Bidirectional option would be both diaphragm at equal amplitudes with opposite polarity.
• Omnidirectional option would be both diaphragms at equal amplitudes with equal polarity.

All other polar pattern options are simply different combinations of amplitude and polarity of the 2 (or more) mic signals.

4. Can Be Achieved Via Physical Means (Adjustable Acoustic Labyrinth)

Some microphones achieve multiple patterns with a single diaphragm by physically changing the acoustic labyrinth of the microphone.

Examples include the RCA 77-DX ribbon microphones with variable “back door” and the Schoeps MK 5 capsule with physical omni/cardioid switch.

5. Will Typically Have Cardioid, Bidirectional, And Omnidirectional Options

• Some mics will have only 2 options (like the aforementioned Schoeps MK 5).
• Many multi-pattern mics offer the 3 most popular polar patterns: omnidirectional, bidirectional, and cardioid (such as the Neumann U 87 AI).
• Other microphones offer plenty of options when it comes to selecting a polar pattern (like the AKG C 414 XLII).
• Yet others will have continuous “infinitely variable” polar patterns.

Examples Of Multi-Pattern Microphones

• Neumann U 87 AI
• AKG C 414 XLII

Neumann U 87 AI

The Neumann U 87 AI is a side-address multi-pattern large-diaphragm condenser microphone.

It utilizes a version of Neumann's K67 capsule, which features two back-to-back 34 mm backplates, each with its own outward-facing diaphragm.

As we see above, the U 87 AI has an omnidirectional, cardioid, and bidirectional option. The polar patterns are fairly consistent, considering that the mic offers such great variety.

AKG C 414 XLII

The AKG C 414 XLII is another side-address multi-pattern large-diaphragm condenser microphone.

It utilizes a version of the famous AKG CK-12 capsule, which audiophiles know for its superb quality and 9-selectable polar patterns.

In the above polar response graphs, we see 5 of the 9 selectable patterns of the AKG C 414 XLII. The remaining 4 patterns are midway points between the above patterns (omnidirectional, wide cardioid, cardioid, hypercardioid, and bidirectional).

For more cool facts about the Neumann K67 and AKG CK-12 microphone capsules, as well as more info on microphone capsules in general, check out my article What Is A Microphone Capsule? (Plus Top 3 Most Popular Capsules).

Back to the table of contents.

Infinitely Variable* Polar Patterns

What is an infinitely variable microphone polar pattern? Some special multi-pattern microphones have infinitely variable mic polar patterns. These patterns are achieved either by continuous (rather than discrete) changes to the amplitudes of each diaphragm/capsule mic signal or by the physical changing of an acoustic labyrinth.

Key Points About The Infinitely Variable* Polar Pattern

1. Available in some multi-pattern microphones
2. May be achieved by physical means (varying the acoustic labyrinth)
3. May be achieved electrical means (varying the phase and amplitude relationships between two or more capsules)
4. Infinitely variable between two polar patterns. This does not mean that any conceivable polar pattern is possible. There are limitations

1. Available In Some Multi-Pattern Microphones

Infinitely variable microphone polar patterns make up a special subset of multi-pattern microphones that is worth mentioning.

2. May Be Achieved By Physical Means (Varying The Acoustic Labyrinth)

Like the aforementioned RCA 77-DX, some infinitely variable polar patterns are achieved by physically altering the path that sound waves must take to reach the rear side of the mic diaphragm.

3. May Be Achieved By Electrical Means (Varying The Phase And Amplitude Relationships Between Two Or More Capsules)

Other microphones, like the Brauner VMA, actually have continuous controls of the amplitudes of their mic signals. Blending these signals with continuously variable amplitude will lead to all sorts of interesting polar patterns.

4. Infinitely Variable Between Two Polar Pattens

Note that infinitely variable doesn't mean we can program whatever pattern we want as a microphone's polar response. It simply means that we can morph between the aforementioned polar patterns and arrive at interesting “midway” patterns.

Examples Of Microphones With Infinitely Variable* Polar Patterns

• Brauner VMA
• RCA 77-DX

Brauner VMA

The Brauner VMA is a side-address large-diaphragm condenser microphone. Its capsule allows for continuously variable polar patterns from Omni to Figure-8.

The Brauner VMA is featured in My New Microphone's Top 11 Best Tube Condenser Microphones On The Market.

RCA 77-DX (Discontinued)

The RCA 77-DX is a vintage side-address ribbon microphone. It had an interesting acoustic labyrinth with a mechanical shutter behind the ribbon. A rotary control on the back of the mic’s grille rotated a metal shutter, which affected the behaviour of the labyrinth. Adjusting the shutter would gradually shift the polar pattern from the ribbon’s natural bidirectional (figure-8) polar pattern.

The RCA 77-DX has been discontinued.

The RCA 77-DX is featured in the following My New Microphone articles:
• 50 Best Microphones Of All Time (With Alternate Versions & Clones)
• Top 12 Best Vintage Microphones (And Their Best Clones)

Back to the table of contents.

Stereo Microphones

What is a stereo microphone, and what polar patterns do stereo microphones have? A stereo microphone is any mic that can output in stereo (two or more mono signals). Stereo mics are designed with at least two diaphragms set up as some sort of coincident pair. Stereo mic capsules typically operate with bidirectional and/or cardioid-type polar patterns.

Key Points About Stereo Microphone Polar Patterns

1. Are achieved by combining the signals of two microphone capsules, most often in a coincident stereo technique
2. Can utilize any polar patterns
3. Common polar pattern pairs include:
   X-Y: two cardioid capsules pointing 90°-135° from one another.
   Blumlein Pair: two bidirectional capsules pointing 90° from one another.
   Mid-Side: one cardioid pattern pointing forward with a bidirectional pattern positioned perpendicular.

1. Are Achieved By Combining The Signals Of Two Microphone Capsules, Most Often In A Coincident Stereo Technique

Unlike the dual-diaphragm capsules and 2 summed mic signals of multi-pattern mics, the dual capsules of stereo mics output 2 individual mic signals that can then be panned left and right in a stereo mix.

Because of the nature of a microphone body, these capsules are generally positioned as a coincident pair.

2. Can Utilize Any Polar Patterns

Though the capsules of stereo microphones could be any polar pattern (and even multi-pattern), they are typically either cardioid or bidirectional.

This is because most coincident pair stereo miking techniques use cardioid and/or bidirectional polar patterns.

3. Common Polar Pattern Pairs Include:

I'll simply reiterate the common stereo microphone patterns:

• X-Y: two cardioid capsules pointing 90°-135° from one another.
• Blumlein Pair: two bidirectional capsules pointing 90° from one another.
• Mid-Side: one cardioid pattern pointing forward with a bidirectional pattern positioned perpendicular.

Examples Of Stereo Microphones

• Schoeps CMXY 4V
• Royer SF-24
• Blue Yeti Pro

Schoeps CMXY 4V

The Schoeps CMXY 4V features 2 side-address condenser capsules (based on the Schoeps Colette series).

The angle between the capsules’ axes can be continuously adjusted between 0° and 180°. The capsules rotate on a gearing system, which forces them to move outward and inward in unison. This results in a constant centre axis for any stereo angle you'd prefer to use.

The CMXY 4V is an excellent stereo microphone for recording with the XY stereo technique.

Royer SF-24

The Royer SF-24 features two side-address bidirectional ribbon diaphragms angled at 90° from one another. The resulting coincident stereo technique is the Blumlein Pair.

Blue Yeti Pro (Discontinued)

The Blue Yeti Pro is a multi-pattern microphone with a stereo option. Stereo mode engages two side-address small-diaphragm condensers with cardioid patterns angled 90° to one another in an XY fashion.

To read more about stereo microphones, check out my article Do Microphones Output Mono Or Stereo Signals?

Back to the table of contents.

Ambisonic Microphones

What is an ambisonic microphone, and what polar pattern do ambisonic microphones have? An ambisonic microphone is a single mic designed to capture sound in a full-sphere surround sound format. Ambisonic mics often include 4-8 cardioid capsules (or more) in order to output sound for 3D ambisonic mixing with mic-specific software. Ambisonic mics are well suited for virtual reality recording.

Key Points About Ambisonic Microphone Polar Patterns

1. Most often achieved with 4 or 8 cardioid capsules evenly positioned around a centre point and directed outward (“tetrahedral” or “octahedral,” respectively)

1. Most Often Achieved With Cardioid Capsules

Regardless of the number of microphone capsules used in an ambisonic microphone, the capsules are typically cardioid.

These unidirectional capsules effectively capture where they point (outward from the ambisonic microphone's centre point). Cardioids are fairly rejecting of side sounds, which helps to isolate them from their adjacent capsules. They also have null points that face inward to the ambisonic centre, which greatly reduces muddiness and phase issues.

Examples Of Ambisonic Microphones

• Rode NT-SF1
• Core Sound OctoMic

Rode NT-SF1

The Rode NT-SF1 is a tetrahedral ambisonic microphone designed with 4 evenly spaced and outward-facing cardioid capsules.

Core Sound OctoMic

The Core Sound OctoMic is an octahedral ambisonic microphone designed with 8 evenly spaced and outward-facing cardioid capsules.

The Core Sound OctoMic is featured in My New Microphone's Best Microphones For Recording Ambience.

Back to the table of contents.

Recap And Polar Pattern Generalities

So there are plenty of microphone polar patterns to know. Please return to this article any time you need a refresher on microphone polar patterns and their applications.

Let's wrap up with a short list of generalities in no particular order of importance:

• All microphones have some amount of off-axis colouration.
• The pressure principle yields omnidirectional microphone polar patterns.
• The pressure-gradient principle yield all directional microphone polar patterns.
• The pressure-gradient principle can yield an omnidirectional pattern in dual-cardioid diaphragm multi-pattern mics.
• The truest form of the pressure-gradient principle yields a bidirectional polar pattern.
• Ribbon microphones are, by nature, bidirectional.
• Multipattern microphones are typically condensers.
• Though supercardioid, hypercardioid, and lobar patterns are film and television essentials, they are rarely used in studio environments.
• Microphones naturally become more directional at higher frequencies
• Microphones naturally become less directional (more omnidirectional) at lower frequencies.
• Top-address and pencil microphones cannot truly be bidirectional.
• Bidirectional microphones exhibit the most proximity effect.
• Omnidirectional microphones exhibit no proximity effect.
• Omnidirectional microphones are practically immune to plosives.
• Lobar polar patterns are achieved by including an interference tube in front of supercardioid or hypercardioid microphone capsules.
• Boundary/PZM hemispherical polar patterns are achieved by mounting a mic capsule flush with a boundary surface.
• Stereo microphones typically use cardioid and bidirectional capsules.
• Ambisonic microphones are made of multiple cardioid capsules pointing outward from a single point.

Related Questions

What microphone polar pattern is best for vocals? Cardioid polar patterns are the preferred polar pattern for vocals in practically all situations (live, studio, broadcast, etc.). Omnidirectional lavalier mics are sometimes chosen of cardioid. However, for the vast majority of applications, cardioid is the ideal choice for vocals.

What is microphone polarity? Microphone polarity most often refers to the polar response pattern of a mic. Alternatively, microphone polarity has to do with a balanced audio signal. Polarity, in this case, tells us which pin (2 or 3) of a mic's output connection carries the positive and negative polarity version of the mic signal.

For more info on microphone polarity, check out my article Microphone Polarity & Phase: How They Affect Mic Signals.

Related My New Microphone Articles

• What Is An Omnidirectional Microphone? (Polar Pattern + Mic Examples)

• What Is A Bidirectional/Figure-8 Microphone? (With Mic Examples)

• What Is A Cardioid Microphone? (Polar Pattern + Mic Examples)

• What Is A Supercardioid Microphone? (Polar Pattern + Mic Examples)

• What Is A Hypercardioid Microphone? (Polar Pattern + Mic Examples)

• What Is A Subcardioid/Wide Cardioid Microphone? (With Mic Examples)

• The Lobar/Shotgun Microphone Polar Pattern (With Mic Examples)

• The Hemispherical Boundary Microphone/PZM Polar Pattern

---

Leave A Comment!

Have any thoughts, questions or concerns? I invite you to add them to the comment section at the bottom of the page! I'd love to hear your insights and inquiries and will do my best to add to the conversation. Thanks!

This article has been approved in accordance with the My New Microphone Editorial Policy.