2 2 2 HARTREY AVE.. EVANSTON. IL. 6 0 2 0 4 U.S.A.
AREA CODE 3121866-2200 CABLE: SHUREMICRO
TWX: 9 1 0 - 2 3 1 - 0 0 4 8 TELEX: 7 2 - 4 3 8 1
1
I U A I A
:K~T
, and
548SH
UNIDYNEm IV
UNIDIRECTIONAL DYNAMIC MICROPHONES
GENERAL
The UNIDYNEB IV Models 548,548SD, and 548SH are dual-impedance unidirectional dynamic microphones shipped connected for low-impedance 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 uniform 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 548SD 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 548SD 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 548SD-CN: Same as Model 548SD, except supplied with professional three-pin male audio con- nector on equipment end of cable. (See Specifications for details on cable.)
.
Unusually effective cardioid (unidirectional) 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
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 (548SH, 548SD, and
548SD-CN) .
Rugged p r o f e s s i ~ n a l 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
548SD-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-Off switch (548SD), with magnetic reed On-Off switch and three-pin pro- fessional audio-connector on equipment end of cable (548SD-CN), and with On-Off switch mounted on attached swivel assembly (548SH).
Copyright 1980, Shure Brothers Inc.
27A1559 (TC)
U.S. Patents 3,132,713, and 3,240,883
Printed in U.S.A.
SPECIFICATIONS
TY pe
Dynamic
Frequency Response
40 to 15,000 Hz (see Figure 1)
6
$
.: w
% a n
TYPICAL FREQUENCY RESPONSE
FIGURE 1
Polar Pattern
Cardioid (unidirectional)-uniform with frequency, symmetrical about axis (see Figure 2) male audio connectort on the microphone end and a professional three-pin male audio connectort on the equipment end t Designed to mate with Cannon XL series, Switchcraft
A3 (Q.G.) series or equivalent connector.
Dimensions
See Figure 3
MODELS 548, 548SD AND 548SD-CN
OVERALL DIMENSIONS
I ,
(1-116 IN I
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)
*O dB
* * 0 dB
IMPEDANCE
Open Circuit Voltage*
Power Level**
- -
. . . . .
-76.0 dB -54.0 dB
(.I58 mV)
High
(2.0 mV)
. . . . . . . . . . . .
-56.0 dB
= 1 volt per microbar
= 1 milliwatt per 10 microbars
Switch
548SD and 548SD-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
548SH: Positive action, permits tilting microphone through 135", suitable for mounting on stand with
Ti"-27 thread
Swivel Adapter
548, 548SD, and 548SD-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, 548SD, 548SH-4.6m (15 ft) two-conductor shielded (rubber-jacketed) with a professional three- pin female audio connectort on the microphone end
548SD-CN-6.lm (20 ft) two-conductor shielded
(rubber-jacketed) with a professional three-pin fe-
(L5f16 IN.)
5 f V - 2 7 THD
I
MODEL 548SH
FIGURE 3
DIMENSIONS
Weight
Net Combined
(less cable) Net
548SH 4609
(16 oz)
548 & 548SD 31 1 g
(1 1 02)
548SD-CN 31 1 g
(1 1 02)
7339
(28% oz)
7239
(25% 02)
7789
(30% oz)
Packaged
9449
(37 oz)
8429
(33 oz)
9759
(38% oz)
OPERATION
Models 548, 548SD, 548SD-CN, and 548SH 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, 548SD, and 548SD-CN are shipped con- nected for low-impedance operation. To change to high impedance (see Figures 4 and 5), proceed as follows:
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.
SLOTTED SET SCREW r
PLUG ELEMENT
7
EDANCE SELECTION
SOCKET
MODELS 548, 548SD AND 548SD-CN
IMPEDANCE SELECTION
-
RECEPTACLE END OF MICROPHONE
FIGURE 4
CARTRIDGE
GROUND
TRANSFORM3 PROFESSIONAL THREE-PIN
TERMINAL-, rTERMINAL C0DED"A"
AUDIO CONNECTORS
..LCE
CABLE
REED
SWITCH
BLACK
I SOCKET (SHOWN IN LOW
:CASE GROUND
POSITIVE PRESSURE PRODUCES POSITIVE VOLTAGE ON PIN 2,
LOW IMPEDANCE; ON PIN I . HlGH IMPEDANCE.
IMPEDANCE POSITIONI
MODELS 548SD AND 548SD-CN
INTERNAL CONNECTIONS
CARTRKXjE TRbNSFORMER PROFESSIONAL THREE-PIN
GROUND TERMIN,#&
TERMINAL-\ [CODED A
AUDIO CONNECTORS
FFUAl F
~ T I !
YELLOW
... -
,BLACK
CABLE
ICASE
SELECTION
POSITIVE PRESSURE PRODUCES POSITIVE VOLTAGE 'OCKET IN
ON PIN 2, LOW IMPEDANCE; ON PIN I, HlGH IMPEDANCE. IMPEDANCE PoSITION)
MODEL 548
FIGURE
5
3. Reconnect 2-terminal impedance selection sock- et in reverse position so that pin 3 of plug ele- ment is inserted in socket terminal "H".
4. Reassemble plug element into microphone and seat setscrew securely by turning out (clock- wise).
Model 548SH is shipped connected for low-imped- ance operation. To change to high impedance (see
Figure 6), proceed as follows:
1. Remove the two No. 2-56 screws holding the switch to connector and switch housing.
2. Remove the nameplate and take the switch out of the switch housing.
3. Proceed as described in steps 2 and 3 above.
4. Re-assemble switch and nameplate to switch housing. Tighten screws securely.
CARTRIDGE TRANSFORMER SWITCH THREE-PIN PROFESSIONAL
WDlO CONNECTORS
MALE FEMPLE
CABLE bT
SHIELD
I I
1 i;'o"g~4$
MODEL 548SH
FIGURE
6
CONNECTIONS
When using the microphone in low impedance, the
BLACK and WHITE cable leads are the "hot" conduct- ors for balanced line connections to a low-impedance amplifier input; the shield is connected to the chassis or amplifier ground.
When using the microphone in high impedance, the
WHITE cable lead is the "hot" conductor for connec- tion to a high-impedance amplifier input; the shield is connected to the chassis or amplifier ground. The
BLACK cable lead should be insulated at the equip- ment end when not used.
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 insure 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 interchange the wires connected to pins 2 and 3 of the connector. To change the phase of a micro- phone, the microphone cartridge leads must be inter- changed (see Figures 5 and 6). This should be per- formed by your dealer, the Shure Factory Service
Department, or other qualified service personnel.
FURNISHED ACCESSORIES
Swivel Adapter (548, 548SD, 548SD-CN)
. . . . . .
Connector Locking Kit (548, 548SD,
548SD-CN)
. . . . . . . . . . . . . . . . . . . . . . . . . . .
Lockplate (548SH)
. . . . . . . . . . . . . . . . . . . . .
.90NR1371
Windscreen
OPTIONAL ACCESSORIES
Line Matching Transformer
. . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Quick Disconnect Adapter
(548, 548SD, 548SD-CN)
(548SH)
Desk Stand
. . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . .
.S37A, S39A, S40A
REPLACEMENT PARTS
Cartridge (all models)
Cable (548, 548SH, 548SD)
(548SD-CN)
. . . . . . . . . . . . . . . . . . . .C59
. . . . . . . . . . . . . . . . . . . . . . . . . C50CN
Screen and Grille Assembly (all models) . . . . . .RK38G
Plug Element (all models)
(548SH)
. . . . . . . . . . . . . . . .
On-Off Switch (548SD, 548SD-CN)
. . . . . . . . . .
. . . . . . . . . . . . . . . . . . . .
ARCHITECTS' SPECIFICATIONS
The microphone shall be a moving coil (dynamic) type with a frequency response of 40 to 15,000 Hz. The unit shall have a cardioid polar characteristic. The cancellation at the sides shall be approximately 6 dB, and the cancellation at 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 connec- tion to high-impedance microphone inputs. (Imped- ance change shall be solderless at the microphone connector.)
The microphone output shall be:
Low Impedance
. . . . . . . . . . . . . . . . -56.0 dB
0 dB = 1 milliwatt per 10 microbars
High Impedance . . . . . . . . . . . . . . . . -54.0 dB
0 dB = 1 volt per microbar
Models 548SD, 548SD-CN, and 548SH shall be equipped with a built-in On-Off switch.
Models 548, 548SD, and 548SD-CN shall be provided with a swivel adapter, adjustable through 90" from vertical ta horizontal, and suitable for mounting on a stand having a %"-27 thread.
Model 548SH shall be equipped with a swivel, ad- justable through 135", and suitable for mounting on a stand having a %"-27 thread.
Models 548, 548SD, and 548SH shall be provided with a detachable 4.6m (15 ft) two-conductor shielded cable with a professional three-pin audio connector*
(female) on the microphone end.
Model 548SD-CN shall be provided with a detachable
6.lm (20 ft) two-conductor shielded cable with profes- sional three-pin audio connectors* (male and female) on the equipment and microphone ends.
The overall dimensions of Models 548, 548SD, and
548SD-CN shall be 157 mm (6-3/16 in.) in length and
40 mm (1-9116 in.) in diameter.
The overall dimensions of Model 548SH shall be 120 mm (4-23/32 in.) in height, 148 mm (5-27132 in.) in depth, and 39.7 mm (1-9/16 in.) in width.
The microphone shall be the Shure Model 548,
548SD, 548SD-CN, 548SH, or equivalent.
*Designed to mate with Cannon XL series, Switchcraft A3
(Q.G.) series or equivalent connector.
GUARANTEE
This Shure product is guaranteed in normal use to be free from electrical and mechanical defects for a period of one year from date of purchase. Please retain proof of purchase date. This guarantee includes all parts and labor. This guarantee is in lieu of any and all other guarantees or warranties, express or implied, and there shall be no recovery for any consequential or incidental damages.
SHIPPING INSTRUCTIONS
Carefully repack the unit and return it prepaid to:
Shure Brothers Incorporated
Attention: Service Department
1501 West Shure Drive
Arlington Heights, Illinois 60004
If outside the United States, return the unit to your dealer or Authorized Shure Service Center for repair.
The unit will be returned to you prepaid.
