Shure 548 data sheet

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222 HARTREV AVE.. EVANSTON, IL 60204 U.S.A,

® -
MICROPHONES AND ELECTRONIC COMPONENTS

AREA CODE 312/866-2200 . CABLE: SHUREMICRO
YELEX: 7241381

TWX: 910- 231-0048

DATA

SHEET UNIDYNE® IV

SERIES

UNIDIRECTIONAL DYNAMIC MICROPHONES

@ ,

MODEL

GENERAL

The UNIDYNE® IV Models 548, 5488B, and 5488H are
dual-impedance unidirectional dynamic microphones
shipped connected for Iowimpedance operation. The
units provide wide range reproduction of music and
voice and can be effectively used outdoors and indoors.

The UNIDYNE IV is ideal for use by professional
entertainers in high quality theater-stage sound sys-
tems and recording, as well as in critical public-address
systems such as those used in political conventions
and legislatures, convention halls, hotels, public audi-
toriums, stadiums, cathedrals and churches.

The UNIDYNE IV has an exceptionally unitorm uni-
directional pickup pattern that provides an effective
solution to feedback problems in reverberant locations,
permits best utilization of space in small studios.
facilitates orchestral placement, and excludes un-
wanted background noise.

The UNIDYNE IV features an extremely rugged all
metal case and a shock-mounted cartridge, insensitive
to handling noise or mechanical vibration.

Models 548 and 548$D can be used as hand-held
microphones or they can be stand-mounted with the
supplied A25B slip-in swivel adapter. Model 548 is
designed for applications where a switch is not re-
quired; Model 54880 is equipped with a magnetic reed
On-Off switch. Model 548SH has an On-Off switch on
the attached swivel assembly for stand-mounting.

VARIATION

Model 54BSD-CN: Same as Model 5488D, except
supplied with professional three-pin male audio con-
nector on equipment end of cable. (See Specifications
for details on cable.)

Copyright mo. 5mm Brothers inc.
27AI559 (TC)

MODEL
548 548$D

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5 MODEL
548$H

Microphone Features:

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

Response especially effective for announcing, nar-
ration, vocal and instrumental music

Shock-mounted cartridge for quiet operation

Convenient selection of either high or low imped-
ance

Built-in long-life On-Off switch (54BSH, 5488B, and
5488D-CN)

Rugged professional three-pin audio connector on
the microphone

Strong, detachable cable especially selected for
effective shielding from hum pickup

Supplied with an .050 wrench and a 4-40 socket
setscrew (see Figure 4) to securely lock the micro-
phone to the cable connector (548, 548SD, and
5483D-CN)

Versatile-for use in the hand or on a stand-
indoors or outdoors

Rugged and dependable under all operating con-
ditions

Available in four versions: without switch (548),
with magnetic reed On-Otf switch (5488B), with
magnetic reed On-Off switch and three-pin pro-
fessional audio-connector on equipment end of
cable (5488D-CN), and with On-Off switch mounted
on attached swivel assembly (548SH).

US. Patents 3,l32,7l3, and 3.240.853
Printed in U.S.A,

MODELS 548. 548$D, and 548$H

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SPECIFICATIONS
Type
Dynamic
Frequency Response
40 to 15,000 Hz (see Figure 1)

mm: m n ..

m .. m
TYPICAL FREQUENCY RESPONSE
FIGURE 1
Polar Pattern

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

TVPlCAL mutton mrERN

TYPICAL momma mrEm

POLAR PATTERN
FIGURE 2

Impedance
Dual. Microphone rating impedance is 150 ohms
(240 ohms actual) for connection to microphone
inputs rated at 19 to 300 ohms and High" for con-
nection to high-impedance microphone inputs. Wired
for low impedance as shipped.

Output Level (at 1,000 Hz)

IMPEDANCE
Low High
Open Circuit Voltage ..... -76.0 dB -54.0 dB
(.158 mV) (2.0 mV)
Power Level ............ -56.0 dB

0 dB = 1 volt per microbar
0 dB = 1 milliwatt per 10 microbars

Switch
54SSD and 54SSD-CN: Built~in magnetic reed On-
Off switch with lockplate. To lock switch in On
position, remove screw on lockplate and turn lock-
plate 180. Reassemble and tighten screw.
548SH: Built-in slide-to-talk, positive detent On-Off
switch mounted on attached swivel assembly; sup-
plied with accessory lockplate.

Cartridge Shock Mount
Internal rubber vibration-isolator

Swivel
54BSH: Positive action, permits tilting microphone
through 135, suitable for mounting on stand with
%-27 thread

Swivel Adapter
548, 5488B, and 54BSD-CN: Positive action, adjust-
able through 90° from vertical to horizontal, permits
easy removal for hand-held use, suitable for mount-
ing on stand with %"-27 thread

Case
Black and satin-chrome finished all-metal case and
grille with stainless steel screen

Cable
548, 548$D, 54BSH-4.6m (15 ft) two-conductor
shielded (rubber-jacketed) with a professional three-
pin female audio connectort on the microphone end
54SSD-CN-6,1m (20 ft) two-conductor shielded
(rubber-jacketed) with a professional three-pin fe-

male audio connectort on the microphone end and
a professional three-pin male audio connectorr on
the equipment end

tDesigned to mate with Cannon XL series, Swltchcratt
A3 (0.6.) series or equivalent connector.

Dimensions
See Figure 3

151 mm
(5345)

22.2 mm 93 mm
(7/3) (SH/tell.)

l E --L.. ..
(152:; cmg o a (rum
é
MODELS 543, saasn AND MBSD-CN
OVERALL DIMENSIONS
F-afinmi Pflww
[ESE/"am
v~ a an:
«m
.1sz
27m.
7! mm (I-I/Ie IN)
(2-7/Emt
,2 M, 5/8'727 m:
(mm Mg); m
MODEL MOSH - OVERALL DIMENSIONS
FIGURE 3
Weight
Net Combined
(less cable) Net Packaged
548$H 4609 7339 9449
(16 oz) (28% oz) (37 oz)
548 & 54880 311g 7239 842
11 oz) (25/: oz) (33 oz)
54BSD-CN 3119 7789 9759
11 oz) (301/2 02) (38% oz)
OPERATION

Models 548, 54880, 54BSD-CN, and 5488H are dual-
impedance microphones for connection to a 19 to 300
ohm rated input or to a high-impedance input. The mi-
crophones are shipped from the factory connected for
low»impedance operation.

The low-impedance connection (as shipped) is
recommended where long cable lengths are required
or under conditions of severe hum disturbance. The
permissible cable length is practically unlimited since
neither response nor level is appreciably affected by
long cables. Shure Model A95 Series Line Matching
Transformers are available for use when a low-imped-
ance microphone line is desirable but the associated
amplifier has a high-impedance input, These trans-
formers provide a proper impedance match between a
19 to 300 ohm microphone line and a high-impedance
input and are available with various input and output
connectors.

IMPEDANCE SELECTION
Models 548, 54BSD, and 54BSD-CN are shipped con-
nected for low-impedance operation. To change to
high impedance (see Figures 4 and 5), proceed as
olows:

1. Remove plug element at receptacle end of mi-
crophone by turning slotted setscrew in (counter-
clockwise) and carefully withdrawing plug ele-
ment from case.

2. Disconnect 2-terminal impedance selection sock-
et from rear of plug element.