What is microphone directivity
The directivity of a microphone means that the microphone picks up sound from different directions. In the field setting, the most important thing is to confirm the type of microphone you are using, so as to reduce the feedback of the sound and where is the best place to place the monitor according to the directivity. In the studio, you can use sensors with different characteristics to make changes. The directivity of the microphone not only affects the way it picks up the sound source, but also affects its performance in a specific room or specific sound system.
The microphone directivity chart describes how it responds to sounds from different directions. The coordinates on the chart tell you how to place the microphone to maximize the pickup of the required sound source while minimizing feedback or picking up background noise. Today, let’s talk about the directivity of several common microphones.
This is the type of microphone most often encountered by singers. It is often described as having a heart-shaped pattern and is usually used in studio recording of human voices. When you don’t want to pick up the audience’s voice or the sound from your monitor, the cardioid microphone is very suitable in this case (when using a cardioid microphone, the monitor should be placed opposite you, 180 degrees from you. ). For example, AKG's C3000, with its cardioid pointing, can effectively reduce the surround sound and the sound reflected by the microphone in the studio. This can help you record in undesirable environments, or reduce the sound of other music around you.
Super cardioid microphone, the big nephew of the cardioid microphone. The pickup area of the super cardioid microphone is narrower than that of the cardioid microphone, and the directivity is more clear. This is more useful for picking up a single sound source on a noisy stage with a lot of ambient noise, and can more effectively eliminate the surrounding noise. But this kind of microphone also picks up sound at the back end, so the monitor speakers must be placed correctly. It is particularly suitable for fixed-point recording of drums and pianos, and its directional characteristics are very suitable for on-site recording that requires isolation (sometimes to isolate interference between instruments, and sometimes to isolate noise). For self-playing and self-singing performance recordings, the crosstalk of super-directional microphones is minimal.
Figure 8 directivity
The shape of the figure-eight microphone is similar to the number 8. It picks up sound from the front and back instead of both sides. It is also called a double cardioid, bidirectional microphone. Usually used in studios, most of them are ribbon or large diaphragm microphones.
Recording performances of two singers is a great use of this type of microphone. One singer can be in the front and one in the opposite direction, which can also reduce the sound reflection in the room.
Omnidirectional microphones were originally called "pressure" microphones. Their diaphragm measures the pressure of sound at a single point in space. Since they cannot provide location information, they are equally sensitive to sounds in all directions. An omnidirectional microphone has the same sensitivity to all angles, which means it can pick up sound evenly from all directions, so the microphone does not have to point in a certain direction.
As the name implies, multi-directional microphones have multiple directional microphones. Many professional condenser microphones have switchable polarity modes. Usually include omnidirectional, cardioid and figure 8 modes. A typical example is AKG's C12VR, which has the above modes, plus six intermediate settings, for a total of nine polar modes. Legendary AKG sound, an enhanced version of the popular AKG C12, with CK12 pickup and original 6072A vacuum tube.
Term explanation: proximity effect
Each directional microphone (cardioid, super cardioid) has the so-called proximity effect. When the microphone is close to the sound source, the bass rate response increases, so the sound is fuller, thereby producing the proximity effect. Professional singers often use this effect. If you want to test the effect, try to gradually bring the microphone closer to your lips while singing, and then listen to the changes in the sound.