Question: What is Proximity Effect?
Answer: Proximity effect is the exaggeration of low-frequency sounds in a directional microphone when the microphone is located very near the sound source.
Proximity effect has an influence on the frequency response of a directional microphone. Starting a few inches from the sound source, you will begin to notice a rising bass response from the microphone as you move the microphone closer and closer to the source. Proximity effect can either be a blessing or a curse, depending on how it is used. A singer can get a deep, earthy sound by singing very close, then change to a more penetrating sound by singing louder while moving the microphone away. This kind of creative use takes some practice, but is very effective. On the other hand, singing at the same volume (with no special effects desired) and moving the microphone in and out will create problems of tonal balance, apart from changes in overall mic level. Some performers also like to work very close at all times to “beef up” an ordinarily “light” voice. Announcers often do this to add emphasis.
Proximity effect can be used effectively to cut feedback in a sound reinforcement situation. If the performer works very close to the mic, and doesn’t need the extra bass, an equalizer can be used to turn down the channel’s bass response. This makes the microphone less sensitive to feedback at low frequencies, since it is now less sensitive to any low-frequency signal arriving from more than a few inches away. (This equalization technique can also help reduce the effect of any handling noise.)
If you should need to avoid proximity effect altogether, however, using an omnidirectional type microphone instead of a directional type can help accomplish this. Whether you should select a directional or omnidirectional type microphone can depend on the application (recording vs. sound reinforcement, for example), the acoustic conditions, the working distance required and the kind of sound you wish to achieve. Directional microphones can suppress unwanted noise, reduce the effects of reverberation and increase gain before feedback. But in good acoustic surroundings, omnidirectional microphones can preserve the “sound” of the recording location, and are often preferred for their flatness of response and freedom from proximity effect. Also, compared to directional microphones, omnidirectional microphones are normally less prone to producing mechanical or handling noise and better at resisting wind noise when used outdoors. Omnis are also less susceptible to “popping” which can be caused by certain explosive consonants in speech (plosives), such as “p,” “b” and “t.” Serious applications may require both types of microphones be readily available in order to select the most suitable type for the application and the kind of sound you wish to achieve.
For assistance selecting the appropriate microphone for your application and to help you achieve your sound, feel free to contact our Audio Solutions Department. We will be happy to assist you.