Understanding Microphone Polar Patterns and Why They Matter

Microphone patterns are often reduced to a few familiar symbols, but knowing where a microphone rejects sound is as useful as knowing where it picks up. This article shows how cardioid, omni and figure-eight patterns affect placement, spill and room tone.

The pattern is frequency-dependent

Cardioid, supercardioid, omnidirectional and figure-eight describe directional sensitivity, not a fixed magical boundary. Real microphones change their off-axis response with frequency, so two cardioids can sound quite different when aimed away from a source.

Use the null, not just the front

Aim a figure-eight side null at an interfering instrument. With a cardioid, try pointing the rear toward unwanted sound. Supercardioid models often have a small rear lobe, which matters when positioning a floor monitor or competing source.

Proximity effect and distance

Directional pressure-gradient microphones commonly gain bass as you move closer. Omni pressure microphones generally do not exhibit the same proximity effect. Change distance before reaching for EQ, and account for wind noise and popping with close vocals.

Try a reproducible listening test

Record the same passage at a fixed gain while changing microphone angle and distance. Compare off-axis coloration and how much room sound enters the recording, not simply the peak level.

Try an off-axis comparison

At a fixed source distance, record the same passage on axis, then at 45 and 90 degrees. Match playback levels and listen for changes in frequency balance and spill. Repeat with omni or figure-eight patterns if available. Aim the figure-eight side null toward unwanted sound; remember that supercardioids can have rear pickup. Consult frequency-dependent manufacturer polar plots. See stereo techniques.