Microphone Positioning: Ensemble Vocals / Choir
A condenser is the type of microphone most often used for choir applications. They are generally more capable of flat, wide-range frequency response. The most appropriate directional type is a unidirectional, usually a cardioid. A supercardioid or a hypercardioid microphone may be used for a slightly greater reach or for more ambient sound rejection. Balanced low-impedance output is used exclusively, and the sensitivity of a condenser microphone is desirable because of the greater distance between the sound source and the microphone. Application of choir microphones falls into the category known as “area” coverage.
Rather than one microphone per sound source, the object is to pick up multiple sound sources (or a “large” sound source) with one (or more) microphone(s). Obviously, this introduces the possibility of interference effects unless certain basic principles (such as the “3-to-1 rule”) are followed, as discussed below. For one microphone picking up a typical choir, the suggested placement is a few feet in front of, and a few feet above, the heads of the first row. It should be centered in front of the choir and aimed at the last row.
In this configuration, a cardioid microphone can “cover” up to 15-20 voices, arranged in a rectangular or wedge-shaped section. For larger or unusually shaped choirs, it may be necessary to use more than one microphone. Since the pickup angle of a microphone is a function of its directionality (approximately 130 degrees for a cardioid), broader coverage requires more distant placement. In order to determine the placement of multiple microphones for choir pickup, remember the following rules:
- Observe the 3-to-1 rule
- Avoid picking up the same sound source with more than one microphone;
- Use the minimum number of microphones.
- For multiple microphones, the objective is to divide the choir into sections that can each be covered by a single microphone.
- If the choir has any existing physical divisions (aisles or boxes), use these to define basic sections.
- If the choir is grouped according to vocal range (soprano, alto, tenor, bass), these may serve as sections.
- If the choir is a single, large entity, and it becomes necessary to choose sections based solely on the coverage of the individual microphones, use the following spacing: one microphone for each lateral section of approximately 6 to 9 feet.
- If the choir is unusually deep (more than 6 or 8 rows), it may be divided into two vertical sections of several rows each, with aiming angles adjusted accordingly.
- In any case, it is better to use too few microphones than too many. In a goodsounding space, a pair of microphones in a stereo configuration can provide realistic reproduction.