Microphone polar patterns define how a microphone captures sound from different directions around it. Understanding these patterns is crucial for achieving professional audio in any recording environment, whether you're setting up a home studio or working on location.
What Are Polar Patterns?
A polar pattern is a visual representation of how sensitive a microphone is to sound coming from different angles. Think of it as a map that shows where the microphone "listens" best. The pattern is typically shown as a diagram viewed from above, with the microphone at the center.
Cardioid Pattern: The Heart Shape
The cardioid pattern gets its name from the Greek word "kardia" (heart) because of its distinctive heart-shaped pickup pattern. This is the most common microphone pattern you'll encounter.
How Cardioid Works
Cardioid microphones are most sensitive to sound coming from directly in front of them (on-axis) and gradually become less sensitive as you move toward the sides. They reject sound from directly behind them (180 degrees off-axis).
Best Uses for Cardioid
- Vocal recording: Perfect for isolating a singer's voice while minimizing room noise
- Instrument isolation: Great for recording individual instruments in a multi-mic setup
- Live performance: Reduces feedback by rejecting sound from monitors behind the mic
- Podcasting: Excellent for single-person recording with minimal room treatment
Omnidirectional Pattern: Equal All Around
Omnidirectional microphones pick up sound equally from all directions. The polar pattern appears as a perfect circle when viewed from above.
How Omnidirectional Works
These microphones have equal sensitivity in all directions around the capsule. This makes them excellent for capturing the natural acoustic properties of a room or recording multiple sound sources simultaneously.
Best Uses for Omnidirectional
- Room ambiance: Capturing the natural reverb and acoustics of a space
- Group recordings: Recording multiple people sitting in a circle
- Field recording: Capturing environmental sounds and soundscapes
- Reference recordings: Getting a natural, uncolored representation of sound
Figure-8 Pattern: Bidirectional Pickup
The figure-8 pattern (also called bidirectional) picks up sound equally from the front and back of the microphone while rejecting sound from the sides.
How Figure-8 Works
This pattern creates two lobes of sensitivity—one in front and one behind the microphone—with null points at 90 and 270 degrees (the sides). The pickup pattern literally looks like the number 8 when viewed from above.
Best Uses for Figure-8
- Stereo recording: Essential for Mid-Side (M-S) stereo recording techniques
- Interview setups: Recording two people facing each other
- Instrument recording: Capturing both the direct sound and room reflection
- Blumlein pair: Creating natural stereo imaging with two figure-8 mics
Choosing the Right Pattern
The key to selecting the appropriate polar pattern lies in understanding your recording environment and goals:
Use Cardioid When:
- You want to isolate the sound source
- You're recording in an untreated room
- You need to minimize background noise
- You're recording close to the source
Use Omnidirectional When:
- You want to capture room ambiance
- You're recording in a great-sounding room
- You need to record multiple sources
- You want the most natural sound possible
Use Figure-8 When:
- You're doing stereo recording techniques
- You need to record from front and back
- You want to reject side noise
- You're creating spatial effects
Multi-Pattern Microphones
Many professional microphones offer switchable polar patterns, giving you the flexibility to choose the best pattern for each recording situation. These typically include cardioid, omnidirectional, and figure-8 options, with some offering intermediate patterns like hypercardioid or wide cardioid.
Practical Recording Tips
Distance Matters: Cardioid mics exhibit proximity effect—bass frequencies increase as you get closer. Use this creatively or position accordingly.
Room Treatment: Omnidirectional mics will pick up more room sound, so ensure your recording space sounds good or use acoustic treatment.
Positioning: For figure-8 mics, be mindful of what's behind the microphone, as it will be picked up just as clearly as what's in front.
Monitoring: Always monitor your recordings through headphones to understand how each pattern affects your sound in real-time.
Understanding polar patterns is fundamental to achieving professional recording results. Whether you're capturing vocals, instruments, or environmental sounds, choosing the right pattern will dramatically improve your audio quality and give you greater control over your recordings.
Share this article: Twitter