Cardioid microphones are just plain old microphones. Its main use is picking up sounds. These sounds have a high gain in both the front and sides, but a low gain from the back. Since the directional sound pickup is somewhat heart-shaped they are called cardioid mics! This type of microphones are very sensitive to sounds that arrive directly in front of the microphone. Additionally, their null point—another angle of sensitivity—is at 180 degrees behind the device.
There are many different types. Some examples are hypercardioid, omnidirectional, and wide cardioid. Here we expand on some of their features in the following section.
Types of Cardioid Microphones
Hypercardiod Microphones
This type tends to have some pick up sounds from the sides, but are far less sensitive to sounds coming from from above and below. Hypercardiod microphones are more directional because they tend to focus on sounds that come directly from the front. Plus, they often discard the off-axis sounds. They have a slight sensitivity when reaching a position of 180 degrees that lies directly behind the microphone. In other words, they real null points at 35 and 45 degrees from the backside of the mic.
Omnidirectional Microphones
Omnidirectional microphones, another kind of cardioid microphones, pick up sounds more evenly. The circle is their traditional representative image. These types of microphones become more directional when they reach higher frequencies. For this reason, it’s essential to position them in the correct direction and axis to the main sound source. This kind tends to pick up more spill sounds and off-axis room reflections than a traditional directional mic. The extra spill might be necessary (or not) depending on the room, the source, the role of the mix, the type of project, and the desired production, as well as the mix style. It’s worth mentioning that omnidirectional mics have an open and transparent sound that is close to the sound source.
Wide Cardioid Microphones
Wide cardioid microphones are less directional than traditional cardioid mics, but more directional than omnidirectional ones. They tend to choose sounds coming from the hemisphere located in front of it. Wide cardioid microphones are equally sensitive to sound coming from the sides, above, and below. Their null point is located behind the device. They are usually represented with an image of a polar pattern. The sound produced by wide cardioid microphones typically balances the openness of omnidirectional mics with the directional control of cardioid microphones.
