Mic Polar Pattern Visualizer

Knowledge Base

How to Read a Polar Pattern

A polar pattern diagram shows how sensitive a microphone is to sound arriving from different angles, with 0° (top of the circle) representing sound coming from directly in front. The closer the curve is to the outer edge at a given angle, the more sensitive the mic is to sound from that direction.

The Common Patterns

• Omnidirectional: Equal sensitivity in every direction, drawn as a perfect circle. Good for room ambience or when the sound source might move around.
• Cardioid: Heart-shaped, most sensitive to the front, rejecting sound from directly behind. The most common pattern for vocals and podcasting.
• Supercardioid / Hypercardioid: Narrower front pickup than cardioid, with a small rear lobe of sensitivity, used when you need tighter isolation from side noise and can tolerate some rear pickup.
• Figure-8 (Bidirectional): Equal sensitivity front and back, near-total rejection from the sides: used for two people facing each other on one mic, or in Mid-Side stereo recording.

Why This Matters for Mic Placement

Understanding your mic's null points (the angles of least sensitivity) tells you where to aim noise sources. A computer fan or air conditioner should sit at the mic's null angle, not just "somewhere off to the side."

FAQ

Q: Why does my cardioid mic still pick up some sound from behind?
A: Cardioid patterns reduce, but don't eliminate, rear sensitivity, real-world mics also rarely match the idealised mathematical pattern shown in a simplified diagram exactly.

Q: Which pattern should I use for a two-person interview on one mic?
A: Figure-8, positioned with each speaker facing one of the two front/back lobes. This is the classic setup for that scenario.

Choosing a pattern for the room you have

A polar pattern describes how sensitive a microphone is to sound arriving from each direction. That single property decides how much of your room ends up in the recording, which in an untreated space matters more than the microphone's frequency response or its price.

Cardioid is the default for good reason. It is most sensitive in front and rejects sound from behind, so pointing it at a speaker in an ordinary room excludes a useful share of the reflections. In an untreated space it is almost always the right starting choice.

Omnidirectional hears everything equally. That makes it excellent in a treated room or very close to a source, where its typically flatter response and absence of proximity effect are advantages. In a reverberant room it captures that reverberation faithfully, which is rarely what anybody wanted.

Figure-of-eight hears front and back while rejecting the sides strongly. It suits two people facing each other across one microphone, and it is the pattern to reach for when the problem is a noise source directly to one side, since its rejection there is deeper than cardioid achieves behind.

Proximity effect comes with directional patterns. Working close to a cardioid or figure-of-eight raises the low frequencies noticeably, which is the warmth broadcasters use deliberately and also the muddiness people fight when they move closer for a better ratio. Omnidirectional patterns do not exhibit it, which is one reason lavalier microphones are usually omni.

Vocabulary

Polar pattern. A description of how sensitive a microphone is to sound from each direction, drawn as a shape on a circle. Determines how much of the room is captured along with the source.

Cardioid. A heart-shaped pattern most sensitive at the front and least sensitive directly behind. The most common pattern, and the safest choice in an untreated room.

Omnidirectional. Equally sensitive in all directions. Usually flatter in response and free of proximity effect, which makes it excellent close up or in a treated space and poor in a reverberant one.

Proximity effect. The rise in low frequencies that occurs as a directional microphone moves closer to a source. Used deliberately for warmth, and the cause of muddiness when working very close without compensating.

Worked example: how much each pattern rejects at four angles

Every first-order microphone pattern follows one formula. Sensitivity equals a plus 1 minus a, times the cosine of the angle from the front, where a is the coefficient for the pattern. The table runs that formula at four angles and gives each result in decibels, relative to sound arriving from the front. The polar plot above draws the same formula.

Read across a row to see where a pattern rejects sound. A cardioid loses 6.0 dB at the sides and reaches its null directly behind. A supercardioid has nulls at 126.0 degrees either side of the front and a rear lobe 11.7 dB down. A hypercardioid has nulls at 109.5 degrees and a rear lobe only 6.0 dB down. The result turns negative past a null, so a rear lobe has opposite polarity to the front. Aim a null at the sound you want to reject. The table shows the ideal shape, and a real microphone departs from it as frequency changes.

Vocabulary

Null. An angle at which a microphone picks up no sound. Where the formula returns zero the pattern has a null, and the table shows it as null. Point a null at the sound to reject, such as a monitor speaker or a second performer.

Rear lobe. A region of pickup behind the nulls of a supercardioid or hypercardioid pattern. It is weaker than the front lobe and has opposite polarity, so sound arriving from behind is picked up at a reduced level and inverted.

On-axis. Directly in front of the capsule, at zero degrees. Every figure in the table is measured against the on-axis level, so the on-axis reading is 0.0 dB for every pattern.