Microphones for a Choir

A hanging cardioid covers a section of riser rather than individual singers, and the coverage width it achieves is set by how far it is from the front row. The working figures below are the ones that consistently produce even coverage without an excessive channel count.

Level falls with distance by the inverse square law: doubling the distance from the singers costs 6 dB. A microphone hung three feet above the front row and one hung six feet above are 6 dB apart before anything else happens, and that 6 dB is exactly the margin you need to get the choir above the room. It is also 6 dB more room reverberation relative to the voices, because the direct sound fell while the reflected sound did not.

Angle does the second half of the work. A cardioid aimed down at the back row reaches the singers furthest away, who are also the quietest at the capsule, while the front row is off axis and closer. That combination flattens the level difference between rows, which is the whole objective. Aiming straight down at the front row instead gives you a loud front row, an inaudible back row and a microphone that hears the ceiling. Every choir system that sounds distant and reverberant is hung too high, aimed wrong, or both.

Choir channels are the most reverberant in the building because the microphones are further from their sources than any others. The processing is mostly about controlling what that distance brings with it.

Choir microphones are the hardest feedback case in a church for one reason: they are far from their source and therefore need the most gain of any channel in the building. A vocal microphone is two inches from a mouth and a choir microphone is four feet from the nearest singer, which is a difference of roughly 27 dB in source level before you start. All of that has to be made up at the console, and every decibel of it is also applied to whatever else the capsule hears, including the loudspeakers.

This is why the usual advice to keep the choir out of the main loudspeaker coverage is not fussiness. The microphones must hang behind the loudspeakers, never in front of them, which in a room where the choir sits behind the platform is straightforward and in a room where the choir sits in a front side gallery is a genuine design problem. It is also why hanging them correctly matters so much: every decibel you gain by hanging lower and aiming better is a decibel you do not have to ask the console for. And it is why handheld microphones never work for a choir, since pointing a handheld up at singers means pointing it at the ceiling and at whatever the ceiling reflects.

Hung too high, almost always, because the rigging point was convenient rather than correct. Aimed at the front row instead of down at the back row. Too many microphones, adding open channels and loop gain without adding coverage, when the riser needed one per ten feet rather than one per four singers. Left open when the choir is not singing. And a choir positioned in front of the loudspeakers, which no amount of equipment solves.

The other common mistake is expecting a choir system to sound like a close miked vocal. It will not and should not: a choir is a blended, distant sound and a system that makes it sound close has usually been pushed so hard that the room came with it. Judge it on whether the words are intelligible at the back and whether the back row of the choir is audible at all, which are the two things the congregation actually notices. For the alternative approaches see hanging choir mics versus handheld.