Figure-8 Microphones in Live Sound: Placement, Rejection, and Handoffs

TL;DR — A figure-8, or bidirectional, microphone accepts sound from its front and rear while strongly rejecting sound from its sides. On a live stage, rotate those side nulls toward unwanted sources and keep wedges, PA spill, and reflections away from both active lobes. Test the exact microphone at show level, because its frequency-dependent pattern and rear pickup can change isolation, tone, and feedback behavior. Document its front axis, rear environment, mount, power requirements, and approved substitute.

What a figure-8 microphone is

A figure-8 microphone has two main pickup lobes: one faces forward and one faces backward. Its deepest rejection regions are approximately 90 degrees to either side. “Bidirectional” describes the same basic geometry.

The pattern is different from cardioid. A cardioid primarily accepts its front and rejects its rear; a figure-8 deliberately accepts both front and rear. It is also different from omnidirectional, which has no comparable side nulls. The omnidirectional versus cardioid guide explains those two reference patterns.

Shure's polar-pattern guide describes the two areas of maximum sensitivity and the two side rejection angles. Treat the manufacturer's polar plot as the starting point for the exact model, not as a promise of identical rejection at every frequency.

Read both sides of the microphone

Some figure-8 microphones have physically similar front and rear faces; others label them or give them different voicing. Confirm the user guide. A microphone rotated 180 degrees may not produce the expected tone even when both lobes remain active.

Place monitors in the nulls, not behind the microphone

For a typical cardioid vocal microphone, directly behind the capsule is a useful starting direction for a wedge. That assumption fails with figure-8 because the rear is an active pickup lobe.

Start by placing unwanted loudspeaker energy toward a side null. Then test with the real microphone height, rotation, working distance, performer position, wedge angle, and required level. If the performer rotates the microphone, its nulls rotate too. A floor position that worked during setup may stop working when the stand is moved or the microphone is tilted.

Do not treat the null as absolute silence. Polar response varies by frequency, and reflections can arrive from other angles. Every PA system can feed back when loop gain becomes high enough. Close placement and controlled loudspeaker coverage still matter.

Decide whether rear pickup helps or hurts

Rear pickup can be useful when the production intentionally needs two opposing sources, room character, or a stereo technique. On a busy live stage, it can instead admit a drum kit, sidefill, audience, reflective wall, or another amplifier.

Before choosing the pattern, inspect the entire rear hemisphere:

1. Mark the primary source and intended front axis.
2. Identify the loudest source behind the microphone.
3. Trace direct PA, wedge, sidefill, and backline paths into both lobes.
4. Listen for reflections from walls, ceilings, screens, and risers.
5. Compare the result at matched useful output against an approved alternative.

A figure-8 model is not automatically “more directional” in the way a production needs. Its strong side rejection may solve one spill path while its rear lobe creates another.

Use ribbon microphones by their actual specification

Many ribbon microphones are naturally figure-8, but the microphone's transducer type and published polar pattern remain separate specifications. Active ribbon designs, passive ribbon designs, and non-ribbon figure-8 condensers can have different output levels, powering requirements, maximum levels, mounting needs, and handling guidance.

Do not apply a blanket phantom-power rule. Read the exact model manual and verify cable and patch condition before connection. The phantom power guide covers the safe order and why balanced wiring matters.

Modern ribbon microphones can be designed for touring use, but that does not make every vintage or passive ribbon equally tolerant of wind, drops, or wiring faults. Specify the model, transport method, wind exposure, stand, shock isolation, and approved substitute.

Test the complete live system

Use a repeatable acceptance sequence:

1. Confirm front and rear orientation before applying gain.
2. Set the intended source distance and angle.
3. Add each wedge, fill, PA zone, and backline source one at a time.
4. Test quiet, normal, and peak source levels at matched useful output.
5. Move the performer and stand through the real operating range.
6. Check FOH, monitors, stream, recording, and press feeds separately.
7. Mute the intended source and listen to spill entering both lobes.

If stability changes, reduce source distance, reduce unnecessary open microphones, rotate the nulls, relocate the loudspeaker, or choose a different pattern before reaching for extreme EQ. Use the microphone feedback guide to test the whole loop.

Put the geometry in the rider

Show the microphone, source, wedge, and backline positions on the stage plot. Add channel, stand, cable, power, owner, and destination details to the input list. “Ribbon mic” alone does not communicate the polar geometry or safe substitute.

Avoid common figure-8 mistakes

• Do not place a wedge directly behind the microphone by cardioid habit.
• Do not ignore the rear lobe when evaluating spill or room reflections.
• Do not assume the side null has equal depth at every frequency.
• Do not rotate the microphone without repeating the level and stability test.
• Do not infer power, fragility, or output level only from the word “ribbon.”
• Do not approve a cardioid substitute without changing loudspeaker placement.

FAQ

What is a figure-8 microphone?

It is a bidirectional microphone with primary sensitivity at its front and rear and strong rejection toward its sides. The exact response changes by model, angle, and frequency.

Where should a monitor go with a figure-8 microphone?

A side null is the logical starting direction, not the active rear lobe. Verify the exact polar plot and test the final microphone, stand angle, wedge position, and show level.

Are figure-8 microphones good for live sound?

They can be when their side rejection and tonal character solve a defined problem. They require deliberate control of rear pickup, loudspeaker geometry, reflections, and performer movement.

Do all ribbon microphones have a figure-8 pattern?

Many ribbon designs are naturally figure-8, but production decisions must follow the exact model's published pattern and manual. Do not use the transducer label as a substitute for specifications.

Does a figure-8 microphone pick up the rear?

Yes. Rear pickup is a defining part of the pattern, not a small accidental lobe. Inspect what is behind the microphone and include it in the placement test.

Make both lobes visible in the advance

Build the stage plot and input list in Techrider.live, mark the microphone's orientation and both active sides, and invite the engineer to edit the same rider. Save the agreed model, geometry, power, destination, substitute, and fallback so the venue can reproduce the tested plan.