Re: omni-directional lavs

Well Danny, I'm going to call into question your statement:

"The physics of sound dictate that every time you double the distance from sound source to mic, the level is not half as much, but one fourth."

This is not accurate, not as I've learned. The physics of sound, in regards to the measuring of acoustic power are bound by the inverse square law. In practice this means that every time you double the distance from your sound source to your measuring point, the power decreases by 6dB. So if you have a sound source emitting sound at 80dB at a distance of one meter, it's power at 2 meters (doubling it's distance) would be 74dB, not 20dB (which would be one fourth the power). Maybe I misunderstood your statement.

Most of us use omni-directional mics as our primary lav mics. However, I will use a cardioid lav mic when necessary. Most of the time you use cardioid lavs in an amplified sound environment (use with a PA system). Omni lavs tend to feed back too easily in this type of environment due to their polarity characteristics.

I use a Sennheiser MKE-102 on Dick Vitale in his office when I do live hits for ESPN. If you know who Mr. Vitale is, you know he is a very loud individual. His office has very hard surfaces and tends to echo easily and has a very "hollow" sound. I've tried the Sennheiser MKH60, Schoeps MK41, Sanken COS-11, Tram TR50 and Countryman EMW mics on him in this room and none sound as good as the cardioid Sennheiser MKE-102. This is just about the only time I use the MKE-102 (the Sanken and Tram mics are my "go-to" lavs). But, cardioids do have their uses.

However, cardioid lav mics don't hide well - they pick up too much clothing noise. Cardioid lavs are bigger than omnis, not smaller. Also, if you accidently block the ports on the side of mic head (with gaff tape), you essentially turn it into an omni mic.

Hope this helps.

Freelance Sound Technician/Mixer