In order to select a microphone for a specific application, it is first necessary to know the important characteristics of the sound source(s) and of the sound system.
Once these are defined, a look at the five areas of microphone specifications previously discussed will lead to an appropriate match.
Finally, correct placement and proper use will insure best performance. In this section, we will present recommendations for some of the most common worship facility sound applications.
The sound system in the following examples is assumed to be of high quality, with balanced low-impedance microphone inputs and available phantom power
The desired sound source for a lectern microphone is typically a speaking voice, though one may occasionally be used for singing.
Undesired sound sources that may be present are nearby loudspeakers (possibly a central cluster overhead), and ambient sound (possibly ventilation or traffic noise, and reflected sound).
The basic performance requirements for a lectern microphone can be met by either dynamic or condenser types, so the choice of operating principle is often determined by other factors, such as appearance.
In particular, the desire for an unobtrusive microphone is better satisfied by a condenser design, which can maintain high performance even in very small sizes. Dynamic types are somewhat larger, but they do not require phantom power.
To match the desired sound source (the voice), the microphone must have a frequency response that covers the vocal range (approximately 100Hz to 15kHz). Within that range the response can be flat, if the sound system and the room acoustics are very good; but often a shaped response, with some presence rise, will improve intelligibility. Above 15kHz and below 100 Hz, the response should roll off smoothly, to avoid pickup of noise and other sounds outside of the vocal range, and to control proximity effect.
The choice of microphone directionality that will maximize pickup of the voice, and minimize undesired sounds, is unidirectional. This type will also reduce the likelihood of feedback since it can be aimed toward the talker and away from loudspeakers.
Depending on how much the person speaking may move about, or on how close the microphone can be placed, a particular type may be chosen: a cardioid for moderately broad, close-up coverage; a supercardioid or a hypercardioid for progressively narrower or slightly more distant coverage.