How to Record a Full Choir

A full choir can be seen as an enormous, singular audio source, that sometimes spreads out its sound over tens of metres, making for a pretty unique job when it comes to recording. How do you make sure that every choir member is captured while the choir sounds like a cohesive whole? In this blog, I’ll explain how just two or three cleverly positioned microphones can result in a balanced and clear stereo-recording.

What Kind of Microphone Do You Need?
Definition & Coverage
Easy Microphone Setups
A-B Setups: Phase Problems and the 3:1 Rule
Polar Patterns
What’s the Optimum Microphone Height?
See Also…

What Kind of Microphones Do You Need?

Generally, condenser microphones are a better choice than dynamic microphones when recording a choir, and are usually set up a little further away from the vocalists than you would set them up to record a single, solo vocalist. Condenser microphones tend to sound more natural when set up at a distance then dynamic microphones. There are two different types of condenser microphones available: large-diaphragm microphones and small-diaphragm microphones. The small-diaphragm condenser is the better of the two when recording a choir, since this kind of microphone is able to capture sound directed at its sides without adding too much colour – something that large-diaphragm microphones just aren’t quite as good at. Tip: Ribbon microphones can also perform brilliantly when it comes to recording a choir.

Definition & Coverage

Making a great recording of a choir essentially depends on finding the balance between enough definition and enough coverage. The further the microphones are placed from the choir, the more complete and cohesive the choir will sound. The flipside is that this can also lead to a less tight, more ‘woolly’ overall sound. The closer you place the microphones to the choir, the more definition you’ll get – so you’ll be able to make out every word. The risk here is that the recording may end up being focussed on a very small group of singers, leaving the rest of the choir in the background. In this case, you get too little coverage. In the following section, I’ll give you a step-by-step explanation of how to strike that magic balance between coverage and definition to get your sound under control and make setting up as straightforward as possible,

Easy Microphone Setups

When recording a small choir, you can use a simple X-Y setup:

How to Record a Full Choir

By using an ORTF-setup, you’re given a little more coverage and a wider stereo image:

How to Record a Full Choir

When recording larger choirs, you’ll soon notice that you’re struggling to get the whole choir in balance, where singers in the middle may sound louder than the singers on the far left and right. This problem can be solved by moving the microphones further apart from one another. This kind of placement is referred to as an A-B setup:

How to Record a Full Choir

The A-B-Setup: Phase Problems and the 3:1 Rule

Since the microphones aren’t set up as close to each other as they are in an X-Y setup, going for an A-B setup could lead to phase problems. If the sound doesn’t reach both microphones at the same moment, specific frequencies are able to cancel each other out leaving an unnatural ‘filtered’ sound. This effect is generally known as the comb filtered effect and is an issue that can be overcome by paying attention to the golden 3:1 rule. The goal here is to make sure that the microphones pick up as little as possible of exactly the same sound. You can achieve this by making the distance between the microphones at least three times as great as the distance between each microphone and the closest sound source. With very large choirs, a standard A-B setup won’t give you enough coverage, so you’ll probably need to add a third microphone and set it up according to the same 3:1 rule to counter any possible phase problems.

Polar Patterns

With an A-B setup, you can also experiment with using microphones with different polar patterns. Two microphones with a cardioid polar pattern will give you a wide stereo image, and you’ll hear relatively little of the room acoustics. Two microphones with an omnidirectional polar pattern will result in a slightly narrower stereo image because the microphones will pick up more of the same sound source. This setup will also sound bigger – more roomy – and the frequency response will be more consistent the further the microphones are placed away from the sound source.

What’s the Optimum Microphone Height?

The imbalance that can often occur when you place your microphones too close to the choir can also occur when the choir is made up of multiple rows. This can lead to the first row sounding much louder in the recording than the back row. Simply by raising the microphones, the distance between the front and back rows can be shortened. Depending on the choir, this can mean that your microphones will have to be raised as high as one metre to even three metres to get the reach you need. In this case, mounting them on a set of stable overhead microphone stands is a must.
What’s the biggest choir you’ve ever recorded and what did your microphone setup look like? Let us know in the comments!