It is no exaggeration to state that miniature lavalier microphones have revolutionized the sound-for-picture industry, particularly film and video location shoots. While excellent sound can be secured from conventional boom and plant microphones, there are a number of applications where the microphone element needs to be placed on the talent and often hidden from view. Fast-moving scenes with a show host moving rapidly through a number of sets is but one possible scenario, or consider the current vogue for long, uninterrupted film scenes in which multiple actors will interact with one another in a long shot.
The name "lavalier" is derived from a French word used originally to describe a jeweled pendant worn on a chain around the neck; these days, a lavalier microphone comprises a small electret or dynamic capsule that can be clipped or otherwise affixed to the talent's clothing or underneath for an invisible plant. The original idea was that talent now would have their hands free for other functions; these days, lavaliers further extend that creative freedom by using a wireless transmitter and RF receiver to carry audio signals to a remotely located sound recorder.
Two variants often are offered by leading manufacturers. A so-called "transparent" lavalier typically features an omnidirectional capsule with gain reduction over distance, but often is more susceptible to background sound. However, such models are considered more forgiving to talent movements, and more closely match the sound of overhead boom mics. On the other hand, "proximity" lavalier mics offer a more pronounced vocal presence, with a more dramatic loss of sensitivity and increased distance, hence providing added suppression of extraneous background noises. Most lavalier microphones are supplied with a useful collection of mounting clips, mounts and windscreens. Recent developments have resulted in even smaller designs that are easier to hide on talent, with smoother low-end response, less wind noise/rumble pickup and a more natural overall sound that matches that sound available from larger boom microphones.
DURABILITY & PATTERNS
The selected lavalier should be rugged enough to sustain consistent sound quality for extended periods of use, particularly where the mic is often exposed to sweat and/or treated roughly by the actors during costume changes. Some lavaliers feature extreme moisture resistance and stronger cables with reinforcing fibers for extra durability.
For added versatility, models are available with omnidirectional or cardioid patterns. To provide a more balanced sound, and overcome any inherent proximity effects from being placed so close to the talent's clothing, miniature lavalier capsules often include a choice of push-on grilles that provide a subtle high-frequency boost. The inevitable loss of clarity when mounted on clothing close to the talent can be compensated by a mid-frequency boost of up to 6 dB. For long shots, lavaliers also can be concealed in the talent's hair, which eliminates clothing noise as he or she moves. Skin-color headsets also are available. Essentially, the lavalier capsule is mounted on a stiff wire mount that loops over the talent's ear.
The key to successful operation is to make sure the mic stays in place during the shoot. Tie clips and other mounts offer reliable attachment, while double-sided tape and pins can ensure that, once hidden from view, the mic doesn't move and produce variable results. Matching dialogue from multiple shots can be tricky if the mic has moved away from its initial position.