Polar pattern of Microphones

A microphone is like a man’s ear, to collect the sounds from surrounding, then transfers to electric signal. According to the principle, basically a microphone is with full direction (omni-directional). There is no sound sensitivity difference from any angles of surrounding. But, in practical, an omni-directional microphone is not able to satisfy all different circumstances and usage. For example, an omni-directional microphone will occur “feedback” noise with speakers easily in broadcast, or users want to correct the sound from specific directions. As the reasons, there are many types of microphones as uni-directiional microphones, super uni-directional microphones, and noise-cancelling microphones…for different usages and circumstances. Below is the general introduction of the different microphone types.

1. Omni-directional microphones:

The type of microphone is with simplest construction, 360° sound collection with similar sensitivity effects. Mostly is used in recording, and is with cheap cost. But if the omni-directional microphone is used in recording studio, shall perform with high sensitivity and excellent R/N ratio, is a kind of high quality and high cost microphone. Therefore, omni-directional microphones are with polarized characters in quality and price. The polar pattern of the type of microphone is as below:

2. Uni-directional microphones:

The type of microphone to collect the sound at the front side will react higher sensitivity than the one from back and side angles. The character will reduce “feedback noise” while used with speakers in broadcast or Karaok place. The type of microphone is very popular and at reasonable price. The polar pattern of the type of microphone is as below:

3. Super Uni-directional microphones:

The type of microphone is more sensitive with the sound of the front angle than the uni-directional microphones. So it is easy to collect the sound from the source at specific angles, and with “tele” function. For example: to record birds sound at trees… In order to reach the super uni-directional effect, the microphone is with complicate construction inside, so the microphone is expensive than other types of microphones. The polar pattern of the type of microphone is as below:

4. noise-cancelling microphones:

The type of microphone is with special construction, can strictly reduce noise from side angles. Many people think uni-directional microphone is a kind of noise-cancelling microphone, actually it is a misunderstanding, they are totally different. The type of microphone only responses to the sound at the front side of microphone in short distance, but is with less response with surroundings. Users need to speak to the microphone with very close distance. Usually the microphone is used in a very noisy circumstance, ex. airport , construction site, or voice identification system…