What is a Bi-directional (Figure-8) microphone?
A bi-directional microphone, also known as a figure-8 microphone, is a type of microphone that picks up sound from two opposite directions. The name “figure-8” comes from the polar pattern of the microphone, which resembles the shape of the number 8 when plotted on a graph. This polar pattern means that the microphone is sensitive to sound coming from the front and back of the microphone, while rejecting sound from the sides.
Bi-directional microphones are commonly used in recording studios, radio broadcasting, and live sound reinforcement. They are popular for their ability to capture sound with a natural and balanced tone, making them ideal for a variety of recording situations.
How does a Bi-directional (Figure-8) microphone work?
Bi-directional microphones work by utilizing a diaphragm that is sensitive to sound waves coming from two opposite directions. When sound waves hit the diaphragm from the front or back of the microphone, it vibrates and converts the sound into an electrical signal. The microphone’s polar pattern ensures that sound from the sides is rejected, focusing only on the sound coming from the front and back.
This unique design allows bi-directional microphones to capture sound with a high level of detail and accuracy. They are often used in situations where a more focused and controlled sound pickup is needed, such as recording vocals, instruments, or podcasting.
When should a Bi-directional (Figure-8) microphone be used?
Bi-directional microphones are best suited for recording situations where a natural and balanced sound is desired. They are commonly used for recording vocals, acoustic instruments, and ensemble performances. Bi-directional microphones are also popular for capturing sound in a room or space, as they can effectively reject unwanted ambient noise from the sides.
These microphones are often used in pairs for stereo recording techniques, such as the Blumlein pair, where two bi-directional microphones are placed at a 90-degree angle to each other to create a realistic stereo image. Bi-directional microphones are also commonly used in radio broadcasting for interviews and podcasts, as they can capture sound from both the host and guest without picking up background noise.
What are the advantages of using a Bi-directional (Figure-8) microphone?
There are several advantages to using a bi-directional microphone in recording situations. One of the main advantages is the natural and balanced sound that these microphones produce. Bi-directional microphones are known for their ability to capture sound with a high level of detail and accuracy, making them ideal for recording vocals and acoustic instruments.
Another advantage of bi-directional microphones is their ability to reject sound from the sides, which helps to focus on the sound coming from the front and back of the microphone. This can be especially useful in noisy environments or when recording in a room with poor acoustics.
Bi-directional microphones are also versatile and can be used in a variety of recording situations. They are commonly used in stereo recording techniques, radio broadcasting, and live sound reinforcement. Their unique polar pattern makes them a valuable tool for capturing sound with clarity and precision.
What are the disadvantages of using a Bi-directional (Figure-8) microphone?
While bi-directional microphones have many advantages, there are also some disadvantages to consider. One of the main disadvantages is their sensitivity to handling noise and plosives. Because bi-directional microphones are designed to pick up sound from two opposite directions, they can be more prone to picking up unwanted noise from handling or breath sounds.
Another disadvantage of bi-directional microphones is their limited pickup pattern. While the figure-8 polar pattern is ideal for capturing sound from the front and back of the microphone, it can be challenging to use in situations where sound needs to be picked up from all directions. In these cases, a different microphone with a more omnidirectional or cardioid polar pattern may be more suitable.
Additionally, bi-directional microphones can be more expensive than other types of microphones, which may be a consideration for those on a budget. However, the quality and versatility of bi-directional microphones often justify the higher cost for professional recording applications.
How to properly use a Bi-directional (Figure-8) microphone in recording situations?
To properly use a bi-directional microphone in recording situations, it is important to consider the microphone’s polar pattern and placement. When using a bi-directional microphone, position the microphone so that the sound source is directly in front or behind the microphone, in line with the diaphragm. This will ensure that the microphone picks up sound from the desired direction while rejecting sound from the sides.
It is also important to minimize handling noise and plosives when using a bi-directional microphone. Use a shock mount or microphone stand to reduce vibrations and movement that can cause unwanted noise. Additionally, use a pop filter or windscreen to minimize plosives and breath sounds that can distort the recording.
When using bi-directional microphones in stereo recording techniques, such as the Blumlein pair, ensure that the microphones are positioned at a 90-degree angle to each other for optimal stereo imaging. Experiment with different microphone placements and angles to find the best sound for your recording.
Overall, bi-directional microphones are a valuable tool for capturing sound with clarity and precision in a variety of recording situations. By understanding how these microphones work and how to properly use them, you can achieve professional-quality recordings with a natural and balanced sound.