Would you buy a microphone from this woman?
Err.. yes? Linda Kruse's work as a product demonstrator gives her excellent practical experience of head worn microphones. In fact for many music and speech applications you have to wonder sometimes why stand-mounted microphones are still so popular.
The problems of stand-mounted microphones for PA are several. The speaker or singer might change their distance from the mic. They might turn to the left or right while speaking or singing. And how often do people give in to a seemingly overwhelming urge to touch the microphone?
Having the microphone on a head band solves the problem of varying distance and of turning the head. It also allows the speaker or singer to move bodily rather than being rooted to the spot. This can result in a more engaging performance or communication.
Potentially the downside is that the conventional stand-mounted microphone is something a speaker or singer can 'hide behind'. OK, it's not exactly hiding, but if you have ever been up on stage you will appreciate the comfort factor of having something between you and your audience.
Head worn microphones may be of cardioid or omnidirectional polar pattern. Omnidirectional microphones are more consistent in tonal quality with respect to distance. Also they are more resistant to popping and breath noise than other types.
A cardioid microphone has other advantages. Since it is sensitive mostly to one side, it has the ability to reject background noise. In fact the background noise will be reduced almost down to a half of what an omnidirectional mic would pick up.
A cardioid microphone will boost the low frequency content of a close-by sound source. So since in this application the mic is used so close to the mouth, low frequencies have to be cut to compensate. This might be done actually inside the mic.
A useful consequence of this is that since the mic only boosts the low frequencies of sound sources that are close, and these are cut, then the low frequency content of other sound sources will be attenuated, by as much as 10 dB or more.
The only potential problem of the cardioid is that it must be more carefully directed towards the sound source.
In summary (courtesy DPA Microphones):
Choose an omni
- when you need a microphone that is not sensitive to positioning
- when the microphone is used by untrained personnel
- when the background noise is not a problem
- when feedback is not a problem
Choose a cardioid
- when background noise is a problem (especially low frequency contents)
- when feedback is a problem