Lavalier
The desired sound source, for a lavalier microphone, is a speaking voice. Undesired sources include other talkers, clothing or “movement” noise, ambient sound, and loudspeakers.
A condenser lavalier microphone will give excellent performance in a very small package, though a dynamic may be used if phantom power is not available or if the size is not critical.
Lavalier microphones have a specially shaped frequency response to compensate for off-axis placement (loss of high frequencies), and sometimes for chest resonance (boost of middle frequencies) .
The most common polar pattern is omnidirectional, though unidirectional types may be used to control excessive ambient noise or severe feedback problems. However, unidirectional types have inherently greater sensitivity to breath and handling noise.
Balanced low-impedance output is preferred as usual. Sensitivity can be moderate, due to the relatively close placement of the microphone. The physical design is optimized for body-worn use.This may be done by means of a clip, a pin, or a neck cord. Small size is very desirable.
For a condenser, the necessary electronics are often housed in a separate small pack, also capable of being worn or placed in a pocket.
Some condensers incorporate the electronics directly into the microphone connector. Provision must also be made for attaching or routing the cable to minimize interference with movement. Wireless versions simplify this task.
Placement of lavalier microphones should be as close to the mouth as is practical, usually a few inches below the neckline on a lapel, a tie, or a lanyard, or at the neckline in the case of a woman’s dress.
Omnidirectional types may be oriented in any convenient way, but a unidirectional type must be aimed in the direction of the mouth.Avoid placing the microphone underneath layers of clothing or in a location where clothing or other objects may touch or rub against it. This is especially critical with unidirectional types. Locate and attach the cable to minimize pull on the microphone and to allow walking without stepping or tripping on it.
A wireless lavalier system eliminates this problem and provides complete freedom of movement. Again, use only high quality cables, and provide phantom power if required.
Good technique for use of lavalier microphones includes:
•—Do observe proper placement and orientation.
—Do use pop filter if needed, especially with unidirectional.
—Don’t breathe on or touch microphone or its cable.
•—Don’t turn head away from microphone.
•—Do mute lavalier mic when using lectern or table microphone.
—Do speak in a clear and distinct voice.