Vocals can be the most important part of many recordings and no matter how good the rest of your mix is if the vocals are not up to scratch it can let the whole thing down. In this article we examine vocal microphone technique – the best way to record various solo performers as well as the art of capturing multiple sound sources from a choir.
Positioning the axis of the microphone between the nose and the mouth is the key to achieving the clearest possible vocal. While we require the singer to be pretty close to the mic angling it slightly off axis can help reduce what are known as plosives and sibilance. These are excessive breathy noises that usually result from sounds such as P, B, D or T. The individual singer’s cadence can have a huge effect on this as well. Tread lightly with your instructions though. It’s not unheard for certain singers to have people removed from studios for criticizing their singing technique. A pop filter is usually a good way to help reduce these unwanted plosives.
Other methods for recording a large group such as a choir can involve using a unidirectional mic, typically a supercardioid or a hypercardioid. These microphones can be used for slightly greater reach or for more ambient sound rejection. Also these will typically be condenser microphones as the sensitive nature of the capsule is ideal for picking up sound sources that are further away from the microphone.
Using these microphones would be classed as area coverage. Rather than using a single microphone multiple mics are used to cover a wide area. The major downside to this is that the more microphones in an area the more likely they are to pick up interference and unwanted ambience. Let’s take our example of a choir. Suggested placement for one microphone would be about a meter in front and about a meter above the heads of the first row. It should centred and aimed at the back row.
A cardioid condenser microphone should be able to pick up about 15-20 voices. For larger choirs multiple microphones be required which is where thing get tricky. To combat this we can apply the following :
The 3-to-1 rule. When using multiple microphones, if the first is 1M away from the sound source the next should be 3M away from the original microphone. This helps reduce phasing but also cuts down on the number microphones present which, if too many at to higher gain structure, can lead to serious feedback problems.
Avoid picking up the same source with multiple microphones. Again this can lead to phasing and or feedback issues. Ideally we want to use the least amount of microphones possible. In this case less really is more.
Dividing the choir into sections that can be covered by a single microphone is the best way to achieve results.
If you have a large choir or group, sections can be determined by the coverage given by a single microphone. You can follow these basic steps but remember each situation may be different. One microphone every 2-3 meters along the front row of the choir. If the choir is quite deep, larger than six rows for example, we can another set of microphones overhead the rear rows but they need to have the 3:1 rule applied. In any case is often preferable to have to few microphones than too many.