User Manual
Microphone Manual
Omnidriectional
Omnidirectional mics are pressure devices, which means they respond directly to changes in air
pressure. They are equally sensitive in all directions and do not exhibit the proximity bass boost
eect inherent in pressure gradient microphones. Omnidirectional microphones have a very
natural sound and are used where there is a need to capture the sound of the room acoustics
or where there are several musicians or singers performing together. Spaced omnidirectional
microphones are often used for the stereo recording of choirs, ensembles etc.
Figure-of-eight
Also a pressure gradient microphone, the gure-of-eight pattern is produced by a diaphragm
open to the air on both sides and gets its name because its polar pattern looks like two
identically sized circles in contact with each other. Sound arriving from the side reaches both
sides of the diaphragm at the same time, which results in the air pressure on both sides of
the diaphragm being equal, so there’s no movement of the diaphragm and consequently
no electrical output. Conversely, on-axis sounds produce the maximum pressure dierential
and hence the maximum output. Figure-of-eight microphones are used in specialist stereo
recording applications and also where a high degree of rejection from 90 degree o-axis
sounds would be useful.
Care and Maintenance
Though capacitor microphones are now far more rugged than in the era of the so-called ‘classic’
models, care must still be taken with all capacitor models to avoid damp conditions, humidity or
excessive dust and cigarette smoke. Microphones brought into a warm studio from a cold vehicle, for
example, may suer condensation on the diaphragm and circuitry, which will compromise the
performance of the microphone until it has completely dried out. It is also important not to subject
the microphone to excessive shocks, such as dropping it onto a hard surface.
Microphones may cleaned using a damp cloth but solvents or thinners should not be used. It is
also important not to use contact cleaners or other aerosols close to the capsule as this may impair
operation.
Mic cables and connectors should be checked regularly for damage. If the cable connecting a tube
microphone to its power supply is damaged, contact your local service agency for a replacement
and under no circumstances attempt to use a cable of a dierent type as this could damage the
microphone circuitry and/or power supply and also runs the risk of electric shock.
Never run a tube microphone power supply with the ground disconnected as this presents the risk of
electric shock. Do not open the microphone case or the power supply case when the power supply is
connected to the mains supply as there are potentially lethal voltages inside.
If a capacitor microphone produces intermittent noise or spluttering sounds, it is probably suering
from condensation and should be dried out in a warm place before further use. Do not attempt to
service a microphone yourself other than to change a tube as this will void the warranty and may
cause serious damage. These considerations apply to all capacitor microphones.
SE Electronics Microphone Manual