It’s an art and a science. There’s a wide array of acoustic instruments in your church and music that runs the gamut from folk to jazz to bluegrass.

What’s involved in making the right microphone choices?  How do you achieve a balanced sound?
What’s the first line of defense?  And what options are there?

In this article, we're going to look at a number of different acoustic instruments – from stringed instruments to keyboards, woodwinds and drums. We'll also include information you'll find useful when thinking in general terms about microphone placement – like the 3:1 Rule.

And while these guidelines are widely accepted in live sound performances, remember  - it's all about experimentation.

Ready to get started? Let's go!

A good place to start is by listening to the sound of the instrument you are miking. How does the sound radiate? Listen up close, and then a few feet away. Place your finger in one ear, then listen to the sound source with the other ear until you find a spot that sounds good, Put the mic there, In some cases, more than one mic is required for an instrument that emanates sound from a number of places at once (a piano is one example).

The closer a microphone is placed to the instrument (to maximize signal level and reduce pick-up of unwanted sounds), the more important placement becomes. Every instrument and microphone has its own characteristics. Every musician has his or her own idea of what sounds good.

Use as few microphones as possible. Every time the number of microphones doubles, the Potential Acoustic Gain of the sound system decreases by 3 dB. This means the volume level of the system must be turned down for every extra mic added. The more microphones you have on stage, the more likely you are to experience feedback. Using fewer microphones will allow more volume before feedback happens.

When multiple microphones are used, the distance between microphones should be three times the distance from each microphone to its intended sound source. This prevents the unpleasant hollow effect called comb filtering, which occurs when two or more microphones pick up the same sound source. This technique is known as the 3-to-1 Rule.

Many of the same microphone rules used in recording apply just as well for live sound. The laws of physics don’t change for sound reinforcement.

 

A major difference between miking for live sound versus recording is proximity to the sound source. The goal in live sound is to get the mic as close as possible to the source for two reasons:

1. Placing microphones as close as possible achieves maximum sound level before feedback occurs.

2. Close-miking reduces leakage and pick-up of unwanted sources.

Here are some general guidelines for mic placement with specific recommendations based on the tonal quality you're seeking. At the end of this article, you'll find a microphone selection chart to provide recommendations on Shure models by instrument type.

Acoustic Guitar

Drum Kit

In most live sound systems, the drum set is miked with each drum having its own mic.  Using microphones with tight polar patterns on toms helps to isolate the sound from each drum.  It’s possible to share one mic with two toms, but then, a microphone with a wider polar pattern should be used.  The snare requires a mic that can handle a very high SPL (sound pressure level) so a dynamic mic is usually the choice.  To avoid picking up the hi-hat in the snare mic, aim the null of the snare mic toward the hi-hat.  The brilliance and high frequencies of cymbals are picked up best by a flat-response condenser mic.

KEYBOARDS

Note: Find additional recommendations and suggestions for grand and upright piano in Shure’s “Microphone Techniques for Live Sound”, downloadable here. 

Violin

Placing the microphone a few inches from the side will produce a well-balanced, natural sound.

Upright Bass

Mandolin, Dobro or Dulcimer

Banjo

Pedal or Lever Harp