Mic positioning and technique is largely a matter or personal tastes – usually whatever “sounds right” probably is right. Nevertheless it’s a good idea to remind ourselves of some of the basics for getting there. The following are a few tips from our friends at Shure that you might consider following when miking musical instruments for sound reinforcement.
Try first to get the instrument to sound good acoustically before miking it.
Use a mic with a frequency response that is limited to the frequency range of the instrument.
To determine a good starting mic position, try closing one ear with your finger. Listen to the sound source with the other ear and move around until you find a spot that sounds good – put the mic there. However, this may not be practical (or healthy) for extremely close placement near loud sources.
Remember that the closer a mic is to a sound source, the louder the source is compared to reverberation or ambient noise.
Place the mic only as close as necessary, keeping in mind Proximity Effect.
When possible, use as few microphones as possible due to the Potential Acoustic Gain rule which tells us (among other things) that the volume level of a system must be turned down for every mic added in order to prevent feedback.
If the sound from your loudspeakers is distorted even though you did not exceed a normal mixer level, the mic signal may be overloading your mixer’s input. To correct this situation, use an in-line attenuator or pad to reduce the signal level from the microphone, or just back it away from the source some.
More than anything, experiment and listen!