Tascam GVI Owner's Manual page 31

Pattern: Most microphones have a choice of polarity patterns. Some have just one pattern
while others have up to 5 patterns. Click on the Pattern Button dropdown to see what is
available for each mic. The choice of pattern can dramatically affect the sonic
character of a microphone.
Omni: Short for Omni-directional, this type of microphone records fairly evenly
from any direction around it. Typically, this choice provides an open sound with
clear highs.
Cardioid: This is a unidirectional microphone; a graphic representation of its
recording pattern resembles a heart, hence the name (Cardio-).
Variations include Wide Cardioid
Figure-8: This is a bi-directional microphone, often used to record two
performers while rejecting off axis sound. The Figure 8 pattern is also used to
creating Mid-Side recordings.
Filter: The type of microphone roll-off filter is selected here. While some mics
have only a flat response, others have the ability to select a roll-off. The roll-off
filters out all the frequencies below the roll-off frequency. The roll-off is often used to
reduce the excess low-end sound of a bass instrument or the boominess in a close proximity
vocal recording. The roll-off frequencies or cutoff points are microphone specific.
and Hyper Cardioid
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