Handbook for Sound Engineers

Microphones 531

Probably the most famous entertainer’s microphone
is the Shure SM58, Fig. 16-85. The microphone has a
highly effective spherical wind screen that also reduces
breath pop noise. The cardioid pickup pattern helps
reduce feedback. The frequency response, Fig. 16-86, is
tailored for vocals with brightened midrange and bass
roll-off. Table 16-2 gives the suggested microphone
placement for best tone quality.

To overcome rough handling and handling noise,
special construction techniques are used to reduce wind,
pop noise, and mechanical noise and to ensure that the
microphone will withstand sudden collisions with the
floor. The Sennheiser MD431, Fig. 16-87, is an example
of a high-quality, rugged, and low-mechanical-noise
microphone. To eliminate feedback, the MD431 incor-
porates a supercardioid directional characteristic,
reducing side pickup to 12% or less than half that of
conventional cardioids.
Another problem, particularly with powerful sound
reinforcement systems, is mechanical (handling) noise.
Aside from disturbing the audience, it can actually

damage equipment. As can be seen in the cutaway, the

MD 431 is actually a microphone within a microphone.

The dynamic transducer element is mounted within an

inner capsule, isolated from the outer housing by means

of a shock absorber. This protects it from handling noise

as well as other mechanical vibrations normally encoun-

tered in live performances.

To screen out noise still further, an internal electrical

high pass filter network is incorporated to insure that

low-frequency disturbances will not affect the audio

signal. A built-in mesh filter in front of the diaphragm

reduces the popping and excessive sibilance often

produced by close micing.

The microphone case is a heavy-duty cast outer

housing with a stainless steel front grille and reed-type

on–off switch. A hum bucking coil is mounted behind

the transducer to cancel out any stray magnetic fields.

16.6.8 Pressure-Gradient Condenser Microphones

One of the most popular studio microphones is the

Neumann U-87 multidirectional condenser micro-

phone, Fig. 16-88, and its cousin, the Neumann U-89,

Figure 16-84. Shure 577B dynamic noise-canceling micro-

phone. Courtesy Shure Incorporated.

Figure 16-85. Shure SM58 vocal microphone. Courtesy

Shure Incorporated.

Table 16-2. Suggested Placement for the SM58

Microphone

Application Suggested Micro-

phone Placement

Tone Quality

Lead and

backup vocals

Lips less than 150 mm

(6 in) away or touching

the windscreen, on axis

to microphone

Robust sound, empha-

sized bass, maximum

isolation from other

sources

Speech from mouth, just above

nose height

Natural sound, reduced

bass

200 mm (8 in) to 0.6 m

(2 ft) away from

mouth, slightly off to

one side

Natural sound, reduced

bass and minimal “s”

sounds

1 m (3 ft) to 2 m (6 ft)

away

Thinner; distant sound;

ambience

Figure 16-86. Frequency response of the Shure SM58

vocal microphone. Courtesy Shure Incorporated.

20 60 100 1 k 10 k 20 k

+10

0

–10

Frequency–Hz

Relative response–dB