Staying with vocals but looping back to miniature designs, there are now a wealth of condensers available for headworn applications. The capsule is mounted on a light boom just off the edge of the mouth or directly in front of the mouth, very close (Figure 7).
The latter type provides exceptional gain-before-feedback and isolation, as well as studio-quality sound. Mini headworn condensers with an omnidirectional pattern are nearly invisible in use yet offer exceptional fidelity for quieter musical acts, and for actors in plays and musicals.
A surface-mounted omni condenser is an example of a boundary mic. These can be gaffer-taped to the side walls of a theater for audience pickup or to the underside of a piano lid for discreet miking.
If you place a conventional microphone on a stage floor to pick up actors, the high end rolls off due to phase interference from floor sound reflections (Figure 8). The delayed reflections combine with the direct sound from the actor, cancelling high frequencies.
Figure 7: Wisconsin Singers director/producer Robin Whitty-Novotny outfitting a vocalist with a Countryman ISOMAX headset mic (with windscreen).
Specially designed floor mics with tiny mic capsules prevent that phase interference because the reflected sound has such a short delay compared to the direct sound. The result is a natural sound without comb filtering. Stage floor mics with a cardioid or supercardioid pattern offer good clarity and gain-before-feedback for area pickup of drama and musicals.
Lectern & Lavalier
Remember the clunky dynamic mics on creaky goosenecks that used to pick up worship leaders at a lectern? Now we have slim, elegant lectern mics thanks to miniaturized condenser mic capsules. These mics adjust silently and come with a cardioid or supercardioid polar pattern.
Clip-on lavalier mics work great for lecturers and worship leaders who like to wander as they talk. They offer a response that rises at high frequencies to compensate for being off-axis to the mouth. A typical placement is 8 inches under the chin.
Figure 8: A stage floor mic (supercardioid boundary design).
Lavaliers have a tiny electret-condenser capsule connected by a thin cable to an XLR connector or wireless transmitter connector. The cable can be hidden under clothing, secured by adhesive bandages to prevent cable-rubbing noise. Actors often hang a lavalier mic just below the hairline. The cable routes through the hair and down to a hidden transmitter. Most mics intended for that application are moisture-resistant.
Lavs are available with omnidirectional or unidirectional polar patterns. A uni (cardioid) pattern reduces feedback and background noise, but is sensitive to cable noise, wind, and breath pops. It’s a good choice if the ambient noise level is high. An omni generally sounds more natural and is smaller. It also allows more head movement without level variations, and is less sensitive to cable noise, wind noise and pops.
If a lavalier must be hidden under clothing, its noise pickup can be minimized by wrapping the mic in a foam cylinder. Some high-frequency EQ boost may be needed to compensate for the muffling effect of clothing. Rycote offers Undercovers, Overcovers and Stickies, which are disposable adhesive pads that reduce clothing rustles and wind noise.
Figure 9: An Audio-Technica AE2500 dual-element cardioid.
You can also utilize two mic types on a single instrument to get a variety of tones without resorting to EQ. For example, the Audio-Technica AE2500 (Figure 9) dual-element cardioid combines both in a single unit. According to A-T, “the dynamic element delivers the aggressive attack of the beater; the condenser captures the round tonalities of the shell.” Several top mix engineers have come to utilize the AE2500.
Live sound is now a great arena to enjoy the advantages provided by condenser mics. Particularly in light of features such as small size and light weight, they can be problem solvers in a wide range of applications.
Bruce Bartlett is a live sound and recording engineer, audio journalist, and microphone engineer (www.bartlettaudio.com).