Proximity Effect - Shure SM87A Manual

SM87A
The Shure Model SM87A is a professional-quality, handheld condenser microphone for
use in sound reinforcement, broadcasting, and studio recording installations. Its super-
cardioid polar pattern provides greater rejection of unwanted sound sources, making it
ideal for miking individual instruments in a multi-microphone setting or for miking single
sources in a reverberant or noisy environment.
The SM87A features a controlled low-frequency roll-off tailored for optimum perfor-
mance when close-miking sound sources. An integral three-stage wind and pop filter
protects against wind and breath noise. Its built-in shock mount reduces stand and
handling noise. The SM87A operates on phantom power.
FEATURES
• Uniform super-cardioid pick-up pattern for maximum gain before feedback and
superior rejection of off axis sound
• Smooth, wide frequency response with gradual presence rise and controlled
proximity effect tailored for vocals
• Steel mesh grille and satin finished aluminum construction resist wear and abuse
• Very low susceptibility to RF and electromagnetic hum
• Minimally affected be varying load impedances
• Phantom powered
• Performs over a wide range of temperature and humidity conditions
• Cartridge shock mount system absorbs mechanical shock and minimizes handling
noise
• Built in pop-filter reduces undesirable wind and breathe noise
• Shure quality, ruggedness and reliability
Power
Condenser microphones such as the SM87A require phantom power supplied by a
mixer, preamplifier, or console.
General Rules for Use
• Aim the microphone toward the desired sound source (such as the talker, singer, or
instrument) and away from unwanted sources.
• Place the microphone as close as practical to the desired sound source.
• Work close to the microphone for extra bass response.
• Use only one microphone to pick up a single sound source.
• Use the fewest number of microphones as practical.
• Keep the distance between microphones at least three times the distance from each
microphone to its source.
• Place microphones as far as possible from reflective surfaces.
• Add a windscreen when using the microphone outdoors.
• Avoid excessive handling to minimize pickup of mechanical noise and vibration.
• Do not cover any part of the microphone grille with your hand, as this will adversely
affect microphone performance.
APPLICATIONS AND PLACEMENT
The following table lists the most common applications and placement techniques.
Keep in mind that microphone technique is largely a matter of personal taste; there is
no one "correct" microphone position.
SUGGESTED MICROPHONE
APPLICATION
PLACEMENT
Vocals Lips less than 15 cm (6 in.) away or
touching the windscreen, on axis to
microphone.
15 to 60 cm (6 in. to 2 ft.) away from
mouth, just above nose height.
20 to 60 cm (8 in. to 2 ft.) away from
mouth, slightly off to one side.
90 cm to 1.8 m (3 to 6 ft.) away.

Proximity Effect

Unidirectional microphones such as the SM87A progressively boost bass frequen-
cies by 6 to 10 dB below 100 Hz when the microphone is at a distance of about 6 mm
(1/4 in.) from the sound source. This phenomenon, known as proximity effect, can be
used to create a warmer, more powerful sound. To prevent explosive low frequency
sound during close-up use, the SM87A bass response gradually rolls off. This provides
greater control and helps the user take advantage of proximity effect.
Avoiding Pickup of Unwanted Sound Sources
A supercardioid microphone has the greatest sound rejection at points 120° toward the
rear of the microphone. Place the microphone so that unwanted sound sources, such
as monitors and loudspeakers, are at these angles, not directly behind it. To minimize
feedback and ensure optimum rejection of unwanted sound, always test microphone
placement before a performance.
MONITOR
RECOMMENDED LOUDSPEAKER LOCATIONS FOR
SUPERCARDIOID MICROPHONES
TONE QUALITY
Robust sound, empha-
sized bass, maximum iso-
lation from other sources.
Natural sound, reduced
bass.
Natural sound, reduced
bass and minimal "s"
sounds.
Thinner, distant sound;
noticeable levels of ambi-
ent noise.
P.A. LOUDSPEAKER
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