Whether the message is wrapped in a sermon, a song or a drama, you want to be certain you've chosen the appropriate microphone for the job so that it comes across clearly. The message must not only be heard, but also be clearly understood, and without distractions that may result from poor microphone selection or technique. There isn't one "does-it-all" microphone that flawlessly captures every word, note of music, or vocal harmony in every situation. Fortunately, however, choosing the right lavalier microphone isn't nearly as difficult as choosing the right words for a sermon, or the right piece of music.
There is a long-held generalization that cardioid -- or directional -- lavalier microphones are best for sound reinforcement in a church setting. While the polar patterns (pickup patterns) of directional microphones include cardioid (directional), supercardioid, hypercardioid, subcardioid, figure-of-eight, and specialty unidirectionals such as shotguns, most directional lavs are cardioid. Certain situations exist in which the directional pickup pattern offers some distinct advantages; other situations exist in which an omnidirectional pickup pattern may be preferable. Deciding between the two types is much easier if we understand the benefits and limitations of each and correlate them to the application.
If your worship setting includes recording, broadcast, and/or assisted listening devices, you may want to give an omni lavalier the opportunity to prove itself on the job. Omnipattern mics have several features that make them an excellent choice for these situations. For one, the omni pattern has, by design, no proximity effect. For example, when you use a directional microphone, you may notice that as you hold the microphone closer to your mouth, the low frequencies are accentuated, making the sound deeper-- and sometimes even a little muddy. Because the normal human voice range is about 500 Hz to 2 kHz, with vowels and bass in the lower frequencies and consonants and treble sounds in the higher ones (think of the high pitch of sibilant consonants such as "s"), the proximity effect can cause bass sounds to overpower consonants, thereby making speech less intelligible. Omni lavs eliminate this problem; speech sounds the same no matter the distance from the mic.
Another benefit of omni mics is their tendency to be less sensitive to plosives. Plosives are consonants such as "b", hard "c", "d", hard "g", "k", "p", "q", and "t", which, when spoken, are characterized by a sudden burst of air. When that burst of air hits a directional mic, it can be reproduced as a loud, usually distracting, low-frequency "pop." You've heard it; the pastor looks down to read from the Bible, preaches powerfully from Peter or Paul, popping the cardioid lav and awakening the congregation with the rushing of a mighty wind. Thanks to the omni's reduced sensitivity to this problem, your congregation will notice fewer "pops," meaning your words are reproduced more clearly, with fewer distractions.
If there is a chance the microphone will be handled or bumped during the service, the omni may be a better choice. Directional lavs have an inherently higher sensitivity to mechanical noise through the cable or capsule housing, meaning that accidentally brushing the mic against clothing or adjusting the cable by hand can result in noise. Choose an omni, which is less sensitive to handling noise, if this is a concern.
Small size and flexible positioning are two more benefits of the omni. Omni elements can be made extremely small; Audio- Technica's AT899, for example, is just 5 mm in diameter and comes in black or "theater beige," a medium beige color that may be covered in makeup and camouflaged next to the skin. One of the limitations of the cardioid lav is that it does need to be positioned carefully; for best sound reproduction, it must be centered beneath the chin and pointed directly at the speaker's mouth. With an omni, positioning is not nearly so crucial; a very small omni gives consistent performance from any angle and is much more forgiving of poor positioning. Instead of having a large, obvious directional microphone clipped dead-center beneath the chin, you can sew it into a costume, tape it to the frame of eyeglasses, or hide it in a thespian's wig, making the omni versatile enough to be used both for conventional speaking and for drama. In this respect, the omni lav can even save you some money by eliminating the need for two different types of mics to cover various situations.
The directional lav's advantage comes in situations that require a greater ratio between the levels of the sound you want (signal) and that which you do not want to pick up (noise). Simply moving any microphone closer to the desired sound source will improve this signal-to-noise ratio, but the directional lav's lower sensitivity to sounds arriving from its sides or rear makes it the winner in this contest. The ambient noise you don't want in the mix may be the voice of another person with a lav. In this case, a directional lav on each talker can reduce the risk of phase interference between the two mics and improve clarity.
Room reverberation is another type of noise you may wish to reduce in the lav. Feedback is a signal-to-noise problem. If your system must operate near the threshold of feedback, or if your lav must be fed through monitors, a directional lav will normally allow you slightly higher gain before feedback. Credit both the mic's cancellation off the sides and rear, and its proximity effect for this edge. In many well-designed and operated systems, an omni lav with a flat frequency response can offer surprisingly good performance without any feedback concerns.
As previously discussed, directional mics cause lower frequencies in speech to be amplified at a greater rate as the microphone is brought closer to the sound source. In some cases this effect can be distracting, even detrimental. In others, however, boosting low frequency may be a boon. For example, some ministers may like the depth and power that a lowfrequency voice projects, especially if their voices are not naturally resonant or deep. A female speaker may appreciate the "authority" that bass boost brings to her expression. Someone with a particularly youthful voice may find that the directional mic helps make his or her voice sound "older." The person using the microphone most, or the sound technician, should have the opportunity to try both omnis and directional lavaliers before deciding whether they like the proximity effect on the speaker's voice.
Economically, an omni lav adds the value of increased versatility: it can be used on a minister, an actor in a drama, a singer in a musical production, or just about anyone else that has a vocal role in your service. An omni is a fine choice in any church in which feedback and ambient noise problems have not been significant. However, if feedback and noise are crucial concerns, the directional lavalier may be the better choice, as it may also be for speakers who appreciate the low-frequency boost of the proximity effect. No matter how many different joyful noises your congregation makes during worship, you will find a microphone that suits the task. Making an educated microphone selection can help ensure that every aspect of your message and your worship service is reproduced cleanly, clearly, and faithfully.
With more than 35 years of experience in the audio industry,
Greg Silsby serves as a marketing director for Audio-Technica U.S., Inc., a
designer/manufacturer of microphones, wireless microphones, headphones, mixers,
and electronics. For more information visit Audio-Technica at: www.audio-technica.com.
