What is a Microphones Polar Pattern?

What is a microphone Polar Pattern? A Comprehensive Guide to Directional Characteristics

In audio engineering and recording practice, the microphone polar pattern is one of the key parameters for assessing a microphone's sound pickup characteristics. It describes the microphone's sensitivity to sounds from different directions, directly impacting recording quality, environmental noise control, and the clarity of voice or instrument pickup.

Understanding polar patterns is crucial for selecting microphone suitable for specific applications. Whether used in recording studios, live performances, conference systems, or film and television production, mastering their principles and applications will enhance the professionalism and reliability of audio capture.

1. What is a microphone Polar Pattern?

A microphone polar pattern diagram, also known as a microphone directional pattern diagram, is a graphical representation of a microphone's sensitivity to sound waves from different directions, expressed in polar coordinates. Typically, 0° represents the front, 180° represents the rear, and 360° represents omnidirectional.

This diagram visually illustrates a microphone's ability to capture sound from the front, sides, and rear, serving as the primary basis for determining its suitability for specific application scenarios.

In simple terms, the polar pattern determines:  

The direction in which the microphone “hears” most clearly;  

How it handles sounds from other directions;  

How it performs in reverberant spaces;  

Whether it is prone to feedback interference or background noise.  

For example:  

Cardioid pattern: Primarily captures front sounds while suppressing side and rear interference;  

Omnidirectional: Responds uniformly to sounds from all directions;

Figure-8 pattern: most sensitive to sounds from the front and back, with minimal pickup from the sides;  

Supercardioid and super-directional: offer stronger directionality and narrower pickup angles;  

Sharp directional: designed for long-distance pickup, with extremely strong directional focusing capability.  

These different polar patterns determine the microphone's suitability for various scenarios.

2. Technical Principles of Polar Patterns  

The formation of polar coordinate graphics depends on the acoustic design inside the microphone, especially the diaphragm structure and air inlet layout:

Pressure gradient microphone: receives sound waves through two openings at the front and back, and uses the Sound Pressure difference to achieve directionality;

Pressure microphone: with only one air inlet, usually omnidirectional;

Composite structure: Simulate multiple pointing modes through circuit processing or mechanical design, such as multi diaphragm condenser microphone.

In practical use, polar coordinate graphics are affected by frequency variations. For example, in the low frequency range, many heart-shaped microphone may exhibit near omnidirectional response; In the high frequency range, it exhibits stronger directionality.

Therefore, when evaluating microphone performance, reference should be made to its polar coordinate graph changes at different frequencies to obtain more accurate application expectations.

Therefore, when evaluating microphone performance, it is important to reference the changes in polar patterns across different frequencies to obtain a more accurate application expectation.

3. Common Polar Pattern Types and Their Application Scenarios

1. Omnidirectional

Omnidirectional microphone have the same response sensitivity to sounds from any direction. They are suitable for scenarios requiring broad sound pickup, such as interviews, meeting recordings, or room-wide recordings.

Advantages: Flat frequency response, good phase consistency, and strong wind noise resistance;

Disadvantages: Prone to environmental noise and reverberation.

2. Cardioid

The cardioid pattern is one of the most common polar patterns, shaped like a heart. It primarily responds to sounds from the front while effectively suppressing interference from the rear.

Advantages: Strong directionality and strong feedback resistance;

Disadvantages: May exhibit proximity effect at close distances.  

3. Supercardioid/Superdirectional  

Narrower than cardioid, offering stronger directionality and higher lateral attenuation, suitable for stage performances, speeches, or scenarios requiring isolation from background noise.  

Advantages: Stronger directionality, better interference resistance;  

Disadvantages: Rear lobe response still exists, requiring careful placement.

4. Figure-8

Strongest response to sounds from the front and back, with almost no response from the sides. Commonly used for stereo recording, two-person interviews, or drum kit recording.

Advantages: Front-to-back symmetry, rich detail;

Disadvantages: Strong suppression of lateral sound sources, not suitable for multi-person recording.

5. Hypercardioid

Hypercardioid microphone have extremely strong directionality and are typically equipped with long tubes or interference tubes to enhance directionality, making them suitable for long-distance pickup, such as in film and television production or documentary interviews.

Advantages: Extremely strong directionality, long pickup distance;

Disadvantages: Sensitive to environmental reflections, requires use with a windscreen.

4. The influence and role of polar diagrams on different types of microphone

1. Condenser microphone

Condenser microphone, with their adjustable directional design, are the most versatile type of microphone in polar diagrams. They often use multi-diaphragm structures or electronic switching methods to support multiple directional modes (such as cardioid, figure-8, omnidirectional, etc.).

This makes condenser microphone highly suitable for recording studios, vocal recording, and instrument sampling, especially in scenarios requiring flexible control of environmental noise.

Additionally, condenser Microphone Sensitivity have very high (see “Detailed Explanation of Microphone Sensitivity”) and, when combined with cardioid or narrow-directional designs, can effectively improve signal-to-noise ratio and reduce background interference.

2. Dynamic microphone

Due to their structural limitations, dynamic microphone typically only have a single directional pattern (such as cardioid). However, this fixed directional design makes them stable and reliable for stage performances and live sound reinforcement.

For example, the S-ONE dynamic microphone uses a cardioid polar pattern to effectively isolate feedback and background noise on stage, enhancing vocal clarity.

Although their dynamic range (see “Detailed Explanation of microphone Dynamic Range”) is not as wide as that of condenser microphone, they still perform exceptionally well in high-intensity sound environments (such as drum kits and guitar amplifiers).  

3. Wireless microphone  

Wireless microphone are widely used in speeches, interviews, live streaming, and mobile filming. The choice of polar pattern directly affects signal reception quality and interference resistance.

Most wireless lavalier microphone use omnidirectional or near-cardioid polar patterns to ensure clear pickup even when the wearer speaks at different angles.

However, omnidirectional microphone are prone to introducing environmental noise, so high-end models often use directional antennas or digital noise reduction algorithms to optimize directionality.

Additionally, the RF stability of wireless microphone is also influenced by polar pattern design—reasonable directionality helps reduce multipath interference and enhance transmission reliability.  

5. The Relationship Between Polar Patterns and Frequency Response  

As discussed in “A Detailed Explanation of Microphone Frequency Response,” frequency response describes a microphone's ability to respond to sounds of different frequencies. Polar patterns reveal the differences in how microphone respond to sounds from different directions.

Together, these two factors determine the microphone's “auditory map” in space.  

For example:  

Some cardioid microphone exhibit good directionality at 1 kHz but may exhibit side lobe responses (Side Lobes) in the high-frequency range, allowing unwanted reflected sounds to enter;  

Omnidirectional microphone, while insensitive to direction, may exhibit resonance peaks at certain frequencies, affecting overall frequency response flatness.

Therefore, when selecting a microphone, it is recommended to consult the manufacturer's multi-frequency polar diagram data to comprehensively evaluate its actual performance.

6. The Importance of Polar Diagrams in Different Application Scenarios  

1. Recording Studios and Music Production  

In recording environments, precise control of the pickup direction is critical. For example:  

Using a cardioid microphone to record vocals to avoid room reflection interference;

Using an omnidirectional microphone for stereo recording or interviews with two people;  

Using a supercardioid microphone to capture details of distant instruments.  

2. Live Performances and Sound Reinforcement Systems  

In stage environments, there is a significant amount of background noise and feedback risk. Selecting microphone with strong directionality (such as cardioid or supercardioid) can significantly improve sound clarity and system stability.

3. Video Conferencing and Remote Communication  

In video conferences, omnidirectional or cardioid microphone can be flexibly selected based on the number of participants and the size of the space. Modern AI noise reduction technology often combines polar pattern information to optimize voice enhancement effects.  

7. Polar patterns are one of the key considerations in microphone selection  

microphone polar patterns not only affect the directionality of sound pickup but also directly impact recording quality, environmental noise control, and system stability. Whether used in recording studios, live performances, or voice interaction devices, selecting the appropriate polar pattern for the application scenario is a crucial step in achieving high-quality audio capture.

As demonstrated in our previous articles such as “microphone Frequency Response Explained” “microphone Sensitivity Explained” and “Dynamic Range of microphone Explained” excellent microphone performance is a systematic engineering endeavor built upon multiple core parameters. Only by comprehensively evaluating all relevant metrics can one truly select the ideal product that meets their specific needs.