Shure 545SD - User Manual

GENERAL
The UNlDYNE
R
III Model 545SD is a dual-impedance, uni-
directional, dynamic microphone. Shipped connected for low-
impedance operation, it features a silent magnetic reed on/off
switch.
The UNlDYNE III is a favorite for instrument pickup and re-
cording, and can be used on lecterns for public address sys-
tems such as those used in political conventions and legisla-
tures, convention halls, hotels, public auditoriums, stadiums,
schools, and churches.
FEATURES
S
Exceptionally uniform cardioid pattern minimizes feedback
in PA applications
S Selectable dual–impedance operation
S Silenat magnectic reed on/off switch with lock option
S Cardioid dynamic
S Frequency response: 50 to 15,000 Hz
CONNECTIONS
When using the microphone with a balanced input, pins 2
and 3 are the audio signal carriers. When using the microphone
with an unbalanced input, use a cable wired with pin 2 as the sig-
nal carrier and pin 3 connected to the cable shield (ground),
such as the Shure C20HZ high-impedance cable.
IMPEDANCE SELECTION
The microphone is shipped connected for low impedance
operation. To change to high impedance, proceed as follows
(refer to Figure 1):
1. Remove plug element at receptacle end of microphone by
turning slotted setscrew in (counterclockwise) and carefully
withdrawing plug element from case.
2. Disconnect 2–terminal impedance selection socket from
rear of plug element.
3. Reconnect 2–terminal impedance selection socket in re-
verse position so that pin 3 of plug element is inserted in
socket terminal “H” (White).
4. Reassemble plug element into microphone and seal set-
screw securely by turning out (clockwise).
ÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎ
IMPEDANCE
SELECTION SOCKET
PLUG
ELEMENT
SET SCREW
PIN 3
IMPEDANCE SELECTION—
RECEPTACLE END OF MICROPHONE
FIGURE 1
POLARITY
All cables and microphones should be tested to ensure
that they have the same polarity. To test two microphones
and/or their cables for proper polarity, connect them to an ampli-
fier and talk or sing into them while holding them three or four
inches apart. The sound from the speakers should be the same
when talking into either microphone or directly between them.
If the sound drops drastically, or if a dead spot is found when
talking between the two microphones, either the microphones
or their cables have opposite polarity.
To change the polarity of a microphone cable, either use
a Shure A15PRS phase reverser or interchange the wires con-
nected to pins 2 and 3 of the three-pin connector at one end of
the cable. To change the polarity of a microphone, the micro-
phone cartridge leads must be interchanged. This should be
performed by your dealer, the Shure Factory Service Depart-
ment, or other qualified service personnel.
SPECIFICATIONS
Type
Dynamic
Frequency Response
50 to 15,000 Hz (see Figure 2)
Polar Pattern
Cardioid (unidirectional)—uniform with frequency, sym-
metrical about axis (see Figure 3)
lmpedance
Dual. Microphone rating impedance is 150 ohms (250
ohms actual) for connection to microphone inputs rated
at 19 to 300 ohms and “High” for connection to high-im-
pedance microphone inputs.
Wired for low impedance as supplied. To change impe-
dance, see sections on lmpedance Selection and Con-
nections.
Output Level (at 1,000 Hz)
“L”
“H”
Open Circuit Voltage* –58.0dB –35.0 dB. . . . . . . . . .
(1.3 mV) (17.6 mV)
*0 dB = 1 volt per Pascal (1 Pa = 94 dB SPL)
Shure Brothers Incorporated
222 Hartrey Avenue
Evanston IL 60202-3696 U.S.A.
Model 545SD User Guide
27A3059 (SC)
E1999, Shure Brothers Incorporated
Printed in U.S.A.

Summary

Product General Information

Microphone Features

Lists key features: cardioid pattern, dual-impedance, magnetic reed switch, and frequency response.

Microphone Connections

Explains microphone connection for balanced and unbalanced audio signal inputs.

Impedance Selection Procedure

Provides step-by-step instructions to change the microphone's impedance setting.

Audio Polarity and Testing

Microphone Specifications

Microphone Type

Dynamic microphone type.

Frequency Response

Frequency range from 50 to 15,000 Hz.

Polar Pattern

Cardioid (unidirectional) pattern, symmetrical about axis.

Microphone Impedance

Dual impedance (150 ohms low, high impedance).

Output Level

Open circuit voltage at 1,000 Hz for low and high impedance.

Physical and Operational Details

On;Off Switch Mechanism

Describes the built-in magnetic reed on/off switch and its locking mechanism.

Cartridge Shock Mount

Features an internal rubber vibration-isolator for shock absorption.

Swivel Adapter Functionality

Details the 90° adjustable swivel adapter for mounting and handheld use.

Microphone Construction

Describes the die-cast case, grille, and screen materials.

Dimensions and Weight

Provides physical dimensions and net weight of the microphone.

Certifications and Compliance

States conformity to EU directives and EMC immunity requirements.

Optional Accessories and Parts

Optional Accessories List

Lists optional accessories like transformers, stands, and windscreens.

Replacement Parts

Lists available replacement parts for the microphone.

Architectural Specifications

Shure 545SD Specifications

General

Brand	Shure
Model	545SD
Category	Microphone
Language	English