Microphone Pick Up Patterns

Understanding microphone pick up patterns is crucial for achieving high-quality audio recordings, whether in a professional recording studio, a live concert, or a simple home setup. The way a microphone captures sound is determined by its polar pattern, which essentially describes the microphone’s sensitivity to sound waves coming from different directions. Each polar pattern has its strengths and weaknesses, making some more suitable for specific applications than others.

Introduction to Polar Patterns

Polar patterns are graphically represented by a circular map, showing how sensitive a microphone is to sound sources positioned around it. The most common polar patterns are omnidirectional, cardioid, bidirectional (figure-eight), and hypercardioid (also known as supercardioid). These patterns help in understanding how to position the microphone relative to the sound source and potential noise sources to achieve the best sound quality.

Types of Polar Patterns

1. Omnidirectional Microphones: These microphones pick up sound from all directions equally. They are useful for capturing ambient sound or when recording in a situation where you want to pick up sound from everywhere, such as in a conference setting. However, their lack of directionality means they can also pick up more background noise.

2. Cardioid Microphones: Shaped like a heart, the cardioid pattern picks up sound from the front and sides but rejects sound from the rear. This pattern is the most commonly used in live performances because it helps to reject feedback from the monitors and reduces the pickup of background noise and stage bleed.

3. Bidirectional (Figure-Eight) Microphones: With equal sensitivity to the front and rear and a significant rejection of sound from the sides, the bidirectional pattern is often used in applications where noise from the sides needs to be minimized, such as in interviews where two people are talking into the same microphone.

4. Hypercardioid (Supercardioid) Microphones: These have a tighter pickup pattern than cardioid microphones, with a stronger rejection of sound from the sides and rear. They are excellent for isolating a sound source in noisy environments but have a slightly larger rear pickup lobe compared to supercardioids.

5. Supercardioid Microphones: These offer a slightly wider pickup at the front compared to hypercardioids but a tighter rear rejection, making them suitable for applications where a bit more isolation from the rear is desired without overly compromising the frontal pickup.

Applications of Different Polar Patterns

• Live Performances: Cardioid microphones are popular for vocals and instruments due to their balanced pickup and background noise rejection.
• Recording Studios: Depending on the desired sound and isolation needs, any polar pattern can be used. For example, omnidirectional microphones can capture a full, rich sound when placed correctly, while cardioid and hypercardioid microphones can provide more isolation.
• Interviews and Podcasting: Bidirectional or omnidirectional microphones can be ideal for interviews, depending on whether the conversation involves two people or a larger group.
• Public Speaking and Presentations: Lavalier microphones with a cardioid or omnidirectional pattern are often used, clipped to the speaker’s lapel to provide clear voice pickup with minimal disturbance.

Choosing the Right Microphone

When selecting a microphone, understanding the needs of your application is key. Consider the type of sound you are trying to capture, the environment in which you are recording, and how much background noise you need to reject. Sometimes, a microphone with a switchable polar pattern can be highly versatile, offering the flexibility to adapt to different recording situations.

Practical Tips for Using Microphones Effectively

• Positioning: Place the microphone in a way that maximizes the pickup of the desired sound source while minimizing background noise and unwanted sound reflections.
• Proximity Effect: Be aware of the proximity effect, where cardioid and hypercardioid microphones can accentuate low frequencies when very close to the sound source, potentially affecting the tone of the sound.
• Gain Staging: Properly adjust the gain levels of your microphone and recording device to avoid distortion and ensure a clean, strong signal.
• Experimentation: Don’t be afraid to experiment with different microphone placements and orientations to find the setup that works best for your specific situation.

Conclusion

In conclusion, understanding microphone pick up patterns is essential for anyone looking to achieve professional-quality audio recordings. By choosing the right microphone for the job and using it correctly, you can significantly improve the sound quality of your recordings and live performances. Whether you’re a seasoned professional or just starting out, having a good grasp of polar patterns and how they apply to different situations can make all the difference in capturing the sound you want.