Spaced omni-directional microphones are best suited to this technique.
Typical spacing is from 2 to 10 feet, centered on the midpoint of the
sound source. The spacing is determined by the width of the sound source
and the distance from it.
For indoor use the general rule of thumb for
microphone placement is to space them one third to one half the distance
from the center to the outer edge of the soundstage. For outdoor use the
lack of reflective surfaces allows for more distance from the sound source.
Here we are more concerned with the "hole in the center" effect. To avoid
this problem, keep the mics between 6 and 10 feet apart. Omnidirectional
microphones offer an excellent sense of acoustic space and the most natural,
uncolored sound of any pickup pattern. However, they require the closest
placement to the sound source for a given direct to reverberant sound ratio
and are more likely to pickup unwanted sounds in the acoustical environment.
The sense of perspective they develop is very natural and "relaxed" sounding.
They are also very immune to wind noise, where directional microphones
require the use of a wind screen outdoors, the omnidirectional does not.
When used indoors, special care must be taken to avoid recording air-
conditioning and low frequency traffic noises.
Omnidirectional microphones
can be either flat to an on axis sound or flat to a reverberant sound field.
For the latter high frequency response will be tilted up. This type of
response is the best choice for outdoor use. Under the best conditions,
outdoors or upclose indoors (see distance rule above), they are unequaled
in their performance.
Back to Spaced Techniques
