Pickup pattern (polar pattern)

A polar plot places the microphone at the centre and shows its relative response as the sound source moves around it. The forward axis is commonly labelled 0 degrees, with the rear at 180 degrees. Multiple curves may show different frequencies because a microphone that looks neatly directional at one frequency can behave quite differently elsewhere in the spectrum.

An omnidirectional pattern responds broadly around the microphone, while a figure-eight responds at the front and rear with strong rejection at the sides. Cardioid, supercardioid and hypercardioid patterns favour the front but have different side sensitivity and rear behaviour. Real microphones approximate these ideal shapes, with construction, grille design and frequency affecting the result.

The pattern describes direction, not distance. There is no hard boundary beyond which a microphone stops hearing. Source level, distance and the acoustic environment determine how much unwanted sound reaches it. A highly directional design can still capture substantial room sound if the desired source is too far away.

Pattern choice influences vocal isolation, instrument spill, room ambience and the stability of stage monitoring. Useful rejection can reduce a competing sound before it enters the signal chain. Equalization can change captured tone, but it cannot cleanly separate two sources that occupy the same frequencies and have already been combined at the microphone.

The rejected directions also shape how a performer should move. A singer who turns away from the microphone may lose high-frequency clarity and level while the monitor continues feeding the capsule from a different direction. Consistent technique and sensible geometry can therefore improve intelligibility more effectively than adding gain or compression.

• Aim the preferred pickup region at the wanted sound.
• Place unwanted sources near suitable low-sensitivity directions where practical.
• Check the actual model plot rather than relying on the pattern name alone.
• Consider movement, reflections and frequency-dependent rejection during rehearsal.

At a small live performance in Dubai, a vocalist uses a cardioid microphone and a floor monitor. The engineer starts by placing the monitor toward the microphone rear, then tests the arrangement with the performer in position. The exact angle changes as the singer raises the stand, so the final check uses the real performance posture rather than an empty stage.

Later, a supercardioid microphone is substituted. The engineer does not assume the old monitor position remains optimal because this pattern has a rear pickup lobe. The manufacturer polar data guides a revised angle, followed by a careful listening test at increasing monitor level. Side reflections and other open microphones are checked before declaring the arrangement stable.

1. Identify the microphone front axis and supported pattern setting.
2. Place the desired source at a sensible working distance and angle.
3. Orient monitors and strong spill sources using the actual rejection directions.
4. Test with realistic movement, room conditions and all required open microphones.
5. Document the successful positions so the setup can be restored.

A familiar error is treating every directional microphone as cardioid. Supercardioid and hypercardioid designs have different null directions and rear lobes, so a generic "monitor directly behind" rule can fail. Shotgun microphones introduce additional frequency-dependent behaviour through an interference tube and are not simply long-range replacements for ordinary vocal microphones in reflective rooms.

Another mistake is confusing polar pattern with electrical polarity. A polarity reversal changes the sign of an electrical waveform; it does not rotate the microphone pickup shape. With multiple microphones, pattern choice can influence spill and phase relationships, but a polarity switch cannot turn an omnidirectional microphone into a cardioid one.

• Do not cover grille openings or acoustic ports with a hand or tape.
• Avoid reading a single frequency curve as a promise across the entire spectrum.
• Do not expect a null to eliminate reflections arriving from other directions.
• Avoid changing a switchable pattern without checking gain, tone and monitor stability again.

Off-axis response describes how the sound changes away from the front axis. Two microphones with similar nominal cardioid shapes may colour spill differently. A smooth off-axis response can be valuable when recording ensembles or capturing a moving speaker, because sounds outside the main axis remain more natural rather than becoming unexpectedly dull, sharp or uneven.

Many directional pressure-gradient designs exhibit proximity effect, an increase in low-frequency response at short distances. Pure pressure omnidirectional designs do not show that same mechanism. A performer moving closer may therefore change tone as well as level. Pattern selection on a multi-pattern microphone can alter both proximity behaviour and the amount of surrounding sound in the recording.

Use monitor-mix principles alongside microphone placement, and consult the audio feedback guide when investigating an unstable system. BarCoe Studios runs hands-on courses for artists, where practising microphone angle and distance can make these directional effects easier to recognise in a real performance.