Handbook for Sound Engineers

528 Chapter 16

ping to the waist also has the advantage of acting as a
strain relief when the cord is accidentally pulled or
stepped on.

A second important characteristic of the microphone
cable is size. The cable should be as small as possible to
make it unobtrusive and light enough so it will not pull
on the microphone and clothing.

Because the microphone is normally 10 inches
(25 cm) from the mouth of the talker and out of the
signal path, the microphone output is less than a micro-
phone on a stand in front of the talker. Unless the torso
is between the microphone and loudspeaker, the lavalier
microphone is often a prime candidate for feedback. For

this reason, the microphone response should be as

smooth as possible.

As in any microphone situation, the farther the

microphone is away from the source, the more freedom

of movement between microphone and source without

adverse effects. If the microphone is worn close to the

neck for increased gain, the output level will be greatly

affected by the raising and lowering and turning of the

talker’s head. It is important that the microphone be

worn chest high and free from clothing, etc. that might

cover the capsule, reducing high-frequency response.

16.6.3 Head-Worn Microphones

Head-worn microphones such as the Shure Model

SM10A, Fig. 16-78, and Shure Beta 53, Fig. 16-79, are

low-impedance, unidirectional, dynamic microphones,

designed for sports and news announcing, for inter-

viewing and intercommunications systems, and for

special-event remote broadcasting. The Shure SM10A

is a unidirectional microphone while the Beta 53 is an

omnidirectional microphone.

Head-worn microphones offer convenient,

hands-free operation without user fatigue. As

close-talking units, they may be used under noisy condi-

tions without losing or masking voice signals. They are

small, lightweight, rugged, and reliable units that

Figure 16-76. Polar response of the microphone in Fig.
16-75. Courtesy Sennheiser Electronic Corporation.

Figure 16-77. Countryman B6 miniature lavalier micro-
phone. Courtesy of Countryman Associates, Inc.

Figure 16-78. Shure SM10A dynamic unidirectional head-

worn microphone. Courtesy Shure Incorporated.