In 1969, Sony shook up the microphone world with the debut of the tiny ECM-50, the smallest broadcast condenser microphone recording engineers had ever seen. Since then, thousands of super-compact lavalier mics have been released, complicating the choice of the right microphone for a specific application.
Before 1969, on-air talent wore sausage-size dynamic microphones hanging around the neck on a lanyard — the origins of the name “lavalier.” Today’s condenser mics are often like a strand of spaghetti and so good they can be used for a wide range of applications.
Different lavalier designs excel in different applications. But the main differentiators in the types of lavs are between omnidirectional and directional pickup patterns, as well as proximity versus transparent sound.
Let’s start with pickup patterns. Omnidirectional microphones pickup sound from all directions equally. Directional microphones focus in one direction and reject other sounds.
Countryman, a specialist manufacturer of tiny lavalier mics, wrote a white paper outlining the differences in directional patterns of mics as a way to guide their potential customers toward picking the right microphone for their application.
For most film and video applications, Countryman advises it is best to use an omnidirectional lav. Omni lavs pick up sound regardless of their direction and don’t need to be lined up with the mouth. Lavs used very close to the mouth — such as earsets, headsets and head-worn lavs — also use the omni pattern because the proximity to the source provides ample gain-before-feedback.
Tie bars can tilt if attached to loose clothing, especially when rigging more active talent. With omni lavs, videographers can get creative with the rigging, mounting to a collar, shoulder straps, hats, eyeglass frames and in the hair. The angle of the microphone is not important. The only limitation with an omni lav is distance.
A lav-size microphone used on a podium provides easy installation and minimal image blockage to cameras and audiences. Click to enlarge.
For microphones used further away from the source — such as for a choir or on a podium — choose a directional mic with a cardioid or hypercardioid pattern.
These lavs or lav-sized mics always need to be pointed directly towards the talent’s mouth.
Directional lavs are also used for sound reinforcement of live lectures and presentations, as they reduce audience noise and limit feedback. They are also used for broadcast studio situations, especially radio, where the talent doesn’t move around too much and there is no concern about seeing the mic.
Cardioid patterns reject more ambient noise compared to an omni, while providing a wide front-lobe for flexibility in placement. Hypercardioid provides the most rejection of ambient noise but has a narrower front-lobe.
A very important thing to remember when using directional lavs: they are highly sensitive to handling and wind noise — far more so than with omni mics. Windscreens, cable clips or tape are highly recommended to help reduce this noise with type of lav.
Another way to categorize lavalier mics is by ones that sound natural regardless of distance (transparent) and those that enhance and emphasize the voice close-up (proximity). The best way to differentiate between the two groups is to simply listen to the microphones.
In another white paper, Audio-Technica, a manufacturer of lavalier mics, suggests starting by holding the lavalier up to your chest and begin speaking. Continue talking while slowly moving the microphone further away.
If there’s a noticeable drop off in fullness and volume after just a foot or two, it’s a proximity lavalier. Transparent lavs will show a slight decrease in volume, but will retain its overall tonal quality even when placed a full arm’s length away.
Some lavs can isolate talent from the background and often emphasize the voice, providing a rich, announcer feel. These mics have less reach, so it’s necessary to rig them higher up on the chest or lapel, ensuring they are no more than several inches from the talent’s mouth.
Proximity lavs are a mainstay among radio and television broadcasters. They are excellent for news anchors, interviews, lectures, studio television and anywhere there is a need to isolate talent from the surrounding environment.
On the opposite end of the spectrum are microphones that provide a much more natural sound. They’re referred to as transparent lavs because they sound so natural that the audience feels like they are transparently eavesdropping on the talent.
These mics show a very gradual taper over a few feet of distance, with just a slight increase of room noise. Because they can cleanly pick up dialog from several feet away, filmmakers often use these microphones as planted mics hidden in the set. Some models can capture quality dialog from four or five feet away.
Picking the right lavalier microphone for the job is more complex today than it used to be, due to the myriad of designs now available. Choosing the right microphone for the job is essential to successful audio for any application.
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