Lapel Microphone "Booms"

One of our ministers is rather animated and likes to look around lots while preaching. So his head is moving but his shoulders (and therefore the mic) are not. This causes him to get very quiet as he looks away from the mic and then suddenly get very loud as he looks "over" the mic. Any suggestions?

We suggest placing the lapel microphone as high as possible on the collar, so that the distance to the mouth is pretty much a constant. Placing the microphone too low down allows the mouth to move into and out of the "field of view" of the microphone, and too low down causes problems with picking up rumbling tummys (oh, and will increase the risk of feedback too!).

The reason for placing a lapel microphone as high as possible is to make it very hard for the user to get their mouth pointing directly at the microphone. High under the chin is a good place because unless you really bend your head forwards, your mouth is pretty much always the same distance from the microphone, wherever you turn your head. I challenge you to make your mouth point at your collar bone without forcing your head unnaturally downwards.

A lot of the sound of a lapel microphone is actually picked up from the throat, and they have (should have!) frequency responses designed to accommodate this. Additionally, as with all microphones, the closer the mic is to the source, the louder the signal picked up (obviously). This means that you can have the level set lower on the PA system, and thus reduce the risk of feedback howling. So, there are strong reasons for suggesting that a lapel mic should be high on the collar.

A point of interest is that news readers etc. on the TV can have their microphones lower down because their head is always facing forwards - there is no danger of them speaking to the floor.

You could also check to see if the "booming" is actually wind noise from speaking straight into the microphone somehow. The addition of a small foam wind/pop shield can help a little to reduce this.

One final tip is that by moving the microphone slightly to the side of the body (which happens on TV presenters as they clip onto their jacket lapel, or to the side on the collar of their T-shirt), gives a more natural sound which is less "nasal".

So, to sum up.... booming or sudden changes in volume only come when you change the distance from the microphone to the mouth. There may be a better place that you can find on your "animated" minister, but we really do find that higher up is best.

Tim Ridgway.