Shure 545SD-LC User manual

Shure Brothers Incorporated
222 Hartrey Avenue
Evanston IL 60202-3696 U.S.A.

Models 545D and 545SD User Guide

MODEL 545D

GENERAL

The UNIDYNE® Ill Models 545D and 545SD are dual­impedance unidirectional, dynamic microphones shipped
connected for low-impedance operation. The microphones
provide wide range reproduction of music and voice and can
be effectively used outdoors and indoors.

The UNIDYNE Ill is ideal for use by professional enter­tainers in high quality theater-stage sound systems and re­cording, as well as in critical public address systems such as

those used in political conventions and legislatures, conven-

tion halls, hotels, public auditoriums, stadiums, cathedrals,

and churches.

The UNIDYNE III features an exceptionally uniform
pickup pattern-provides an effective solution to feedback
problems in reverberant locations, permits best utilization of

space in small studios, facilitates orchestral placement, and

provides practically complete exclusion of unwanted noises.

Model 545D is designed for applications where a switch
is not required. Model 545SD is equipped with a magnetic
reed On-Off switch

VARIATIONS

Model 545SD-CN: Supplied with cable (See Specifi-

cations for details on cable.)

Models 545D-LC and 545SD-LC: Supplied without

cable.

MODEL 545SD

Features

Unusually effective cardioid pickup pattern reduces
feedback (annoying loudspeaker “squeals”) and pre­vents echoing (boominess) that sometimes occurs in
partially filled halls. Can also be used closer to loud­speakers than usual without creating feedback prob­lems

Excellent reproduction of voice and music
Shock mounted cartridge for quiet operation
Quick, neat, solderless impedance selection
Built-in, long-life, magnetic reed ON/OFF switch

(545SD)

Rugged professional three-pin audio connector on the

microphone

Strong,
tive

Versatility-for use in the hand or on a stand-indoors

or outdoors

Available in three versions: without switch or cable

(545D-LC), with switch and cable (545SD-CN), and
with switch but without cab/e (545SD-LC)

detachable cable especially selected

for effec-

shielding from hum pickup (545SD-CN)

© 1998, Shure Brothers Incorporated

27A2237 (RA)

Printed in U.S.A.

SPECIFICATIONS

Type

Dynamic

Frequency Response

50 to 15,000 Hz (see Figure 1)

TYPICAL FREQUENCY RESPONSE

FIGURE 1

Polar Pattern

Cardioid (unidirectional)-uniform with frequency,
symmetrical about axis (see Figure 2)

on lockplate and turn lockplate 180°. Reassemble and
tighten screw.

Cartridge Shock Mount

Internal rubber vibration-isolator

Cable

545SD-CN: 6.1 m (20 ft) two-conductor shielded,
detachable, with professional three-pin audio
connectors* on microphone and equipment ends

*Designed to mate with Cannon XL series, Switchcraft

A3 (Q.G.) series, or equivalent connector.

Swivel Adapter

Positive action, adjustable through 90° from vertical to
horizontal, permits easy removal for handheld use,
suitable for mounting on stand with 5/8”-27 thread

Case

Chrome-plated die casting with ARMO-DUR® grille
and stainless steel screen

Dimensions

See Figure 3

TYPICAL POLAR PATTERNS

FIGURE 2

Impedance

Dual. Microphone rating impedance is 150 ohms (275
ohms actual) for connection to microphone inputs
rated at 19 to 300 ohms and “High” for connection to
high-impedance microphone inputs.

Wired for low impedance as supplied. To change im­pedance, see sections on Impedance Selection and
Connections.

Output Level (at 1,000 Hz)

“L”

Open Circuit Voltage* . . . . . . . .

Power Level** . . . . . . . . . . . . . .

*0 dB = 1 volt per microbar

**0 dB = 1 milliwatt with 10 microbars

-78.0dB

(0.13 mV) (1.76 mV)

-58.5dB

-55.0 dB

Phasing

Positive pressure on diaphragm produces positive
voltage on pin 2 in low impedance and on pin 1 in
high impedance (with respect to pin 3). See Figure 5.

Switch

545SD: Built-in magnetic reed On-Off switch with

lockplate. To lock switch in On position, remove screw

“H”

OVERALL DIMENSIONS

FIGURE 3

Net Weight (less cable)

255 grams (9 oz)

Packaged Weight

545SD-CN: 1042 grams (2 lb, 4 3/4 oz)
545D-LC and 545SD-LC: 556 grams (1 lb 3 3/4 oz)

Certifications

Conforms to European Union directives, eligible to
bear CE marking; meets European Union EMC Immu-

nity Requirements (EN 50 082-1, 1992); RF radiated
(IEC 801-3); ESD (IEC 801-2); EFT (IEC 801-4).

IMPEDANCE SELECTION

The microphones are shipped connected for low-

impedance operation. To change to high impedance (see

Figures 4 and 5), proceed as follows:

Remove plug element at receptacle end of microphone

1.
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

reverse position so that pin 3 of plug element is inserted

in socket terminal “H”.

4.

Reassemble plug element into microphone and seal
setscrew securely by turning out (clockwise).

IMPEDANCE SELECTION-

RECEPTACLE END OF MICROPHONE

FIGURE 4

change the wires connected to pins 2 and 3 of the connector.
To change the phase of a microphone, the microphone car­tridge leads must be interchanged (see Figure 5). This
should be performed by your dealer, the Shure Factory Ser­vice Department, or other qualified service personnel.

FURNISHED ACCESSORY

Swivel Adapter

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A25E

OPTIONAL ACCESSORIES

Line Matching Transformer
Desk Stand
Isolation Mount

Dual Mount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A25M

Windscreen
Cable, LO-Z (6.1 m - 20 ft)
Cable, LO-Z (6.1 m - 20 ft, mic connector only)
Cable, HI-Z (6.1 m-20 ft)

. . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . A95 Series

S37A, S39P

A55M

A2WS

. . . . . . . . . . . . . . . . . . . . C20H

. .

C20D

. . . . . . . . . . . . . . . . . . . . .

C2OP

REPLACEMENT PARTS

545D-LC

Cartridge

. . . . . . . . . . . . . .

Plug Element RK169P

R45

545SD-LC

R45 R45

—

RK169P RK169P

545SD-CN

C20H

ARCHITECTS’ SPECIFICATIONS

The microphone shall be a moving coil (dynamic) type
with a frequency response of 50 to 15,000 Hz. The unit shall
have a cardioid polar characteristic. The cancellation at the

INTERNAL CONNECTIONS

FIGURE 5

CONNECTIONS

When using the microphone in low impedance, the
cable conductors from connector pins 2 and 3 are the audio
signal carriers. Connect the shield to amplifier or chassis
ground.

When using the microphone in high impedance, the
cable conductor from pin 3 and the shield are the audio sig-

nal carriers. Connect the conductor from pin 3 to the “hot”
amplifier input; connect the shield to amplifier or chassis
ground. An unused lead attached to pin 2 should be insu­lated before attaching a connector to a two-conductor

shielded bare-ended cable.

PHASING

To test two microphones and/or their cables for proper
phasing, connect them to an amplifier 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 they are
in phase with each other. If the sound drops drastically, or if
a dead spot is found when talking between the two micro­phones, either the microphones or their cables (low imped­ance only) are out of phase. All cables and microphones
should be tested in this manner to ensure that they are in
phase with each other.

To change the phase of a low-impedance microphone
cable, either use a Shure A15PRS Phase Reverser or inter-

the rear shall be 15 to 20 dB. The microphone shall be dual
impedance with a rated impedance of 150 ohms for connec­tion to microphone inputs rated at 19 to 300 ohms and “High”
for connection to high-impedance microphone inputs. Impe­dance change shall be solderless at the microphone con­nector.

The microphone output shall be:

Low Impedance . . . . . . . . . . . . . . . . . . . . . . . . . .

(0 dB = 1 milliwatt per 10 microbars)

High Impedance. . . . . . . . . . . . . . . . . . . . . . . . . . .

(0 dB = 1 volt per microbar)

audio connector.* Models 545SD-CN and 545SD-LC shall

The microphone shall be provided with a swivel adapter,

able for mounting on a stand having a 5/8”-27 thread.

The overall dimensions of the microphone shall be 157

mm (6-3/16 in.) in length and 31.9 mm (1-1/4 in.) in diameter.

The microphone shall be the Shure Model 545D-LC,

545SD-CN, 545SD-LC or equivalent.

*Designed to mate with Cannon XL series, Switchcraft

A3 (Q.G.) series or equivalent connector

The Sound of Professionals...Worldwide™

Shure Brothers Incorporated

222 Hartrey Avenue, Evanston IL 60202-3696