222 HARTREY
AVE.,
EVANSTON.
IL.
60204
U.S.A.
@ AREACODE312/328-9000
.
CABLE: SHUREMICRO
DATA
SHEET
MODEL
549
UNIDYNE IV
UNIDIRECTIONAL DYNAMIC MICROPHONE
WITH BUILT-IN VIBRATION-ISOLATION SHOCK MOUNT
GENERAL
The Model 549 Unidyne IV Microphone is a rugged dynamic microphone built to provide wide range re- production of music and voice. It has an exceptionally uniform and effective unidirectional pickup pattern.
The microphone is particularly suitable for high quality theater-stage sound systems, recording, cathe- drals and churches, and other critical public address systems such as those used in political conventions and legislatures, hotels, stadiums, and public audito- riums.
Microphone Features: m Unusually effective cardioid pickup pattern elim- inates feedback (annoying loudspeaker "squeals") and prev'ents echoing (boominess) that some- times occurs in partially-filled halls. The micro- phone can be used closer to loudspeakers than usual without creating feedback problems
Response especially effective for announcing, narration, vocal music, and instrumental groups
Cartridge and microphone body separately shock mounted for quiet operation
Convenient impedance selection
An accessory switch adapter furnished to serve in applications where an On-Off switch is nec- essary at the microphone
Positive action detent switch
Dependability under all operating conditions
The Model 549 is dual impedance for connection to microphone inputs rated at 25 to 200 ohms.
The microphone is recommended where long cable lengths are required or under conditions of severe hum disturbance. The permissible cable length is prac- tically unlimited, since neither response nor level is appreciably affected. Shure Model A95 Series Line
Matching Transformers are available for use in those cases where a low-impedance microphone line is desirable but the associated amplifier has a high-im- pedance input. These transformers provide a proper impedance match between a 25-200 ohm microphone line and a high-impedance input, and are available with various input and output connectors.
SWITCH ADAPTER INSTALLATION
Remove the impedance switch cover plate by remov- ing the two 2-56 binding head machine screws at each end of the cover plate. Position the switch plate in place of the cover plate. (The key of the switch plate must be set into the slot of the impedance change switch in the microphone). Replace the two 2-56 bind- ing head machine screws.
The center position on the switch plate marked "0" is the Off position; "H" is the 150 ohm position;
"L"
is the 38 ohm position. Most applications require use of only one impedance. In this case, insert the small
2-56 fillister head screw in the threaded hole below the impedance position NOT being used. This prevents the switch from accidentally being turned to the wrong impedance setting during use as On-Off switch.
Copyright 1975, Shure Brothers Inc.
27A512 (OJ) (OVER)
ARCHITECTS' SPECIFICATIONS
The microphone shall be the Shure Model 549 or equivalent. 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 char- acteristic. The cancellation at the sides shall be ap- proximately 6 dB, and the cancellation at the rear shall be 15 to 20 dB. The microphone shall be a dual-imped- ance unit with rated impedances of 38 ohms and 150 ohms for connection to microphone inputs rated at
25 to 200 ohms. Impedance change shall be by means of a three-position Impedance-Off switch for setting the microphone for 38 ohms
("L"
position), 150 ohms
("H" position), or Off ( " 0 " position).
The microphone output shall be:
38 ohms
150 ohms
(0 dB = 1 milliwatt with 10 microbars)
The microphone shall be equipped with a vibration- isolator in combination with a swivel adjustable through
180". The microphone shall be suitable for mounting on a stand with a 5/8"-27 thread. The microphone con- nector is designed to mate with a professional three-pin female audio connector such as the Cannon XL series,
Switchcraft A3 (Q.G.) series or equivalent connector.
The overall dimensions of the microphone shall be
129 mm (5-3/32 in.) in length, 39.7 mm (1-9/16 in.) in width, and 155 mm (6-7164 in.) in depth.
SPECIFICATIONS
.
Dynamic
Frequency Response
40 to 15,000 Hz (see Figure 1)
FREUlEffiY IN M R T Z
TYPICAL FREQUENCY RESPONSE
FIGURE 1
U.S.
Patents 3,132,713 and 3,240,883
Printed i n U.S.A.
Polar Pattern
Cardioid (unidirectional)-uniform with frequency, symmetrical about axis (see Figure 2)
Net Weight
539 grams (1 Ib 3 oz)
Packaged Weight
758 grams (1 Ib 10% 02)
TYPICAL DlRECTlONAL PATTERN
FIGURE
2
Impedance
Dual. Microphone rating impedance "L" is 38 ohms
(80 ohms actual) and microphone rating impedance
"H" is 150 ohms (340 ohms actual) for connection to microphone inputs rated at 25 to 200 ohms.
Shipped with impedance switch at 150 ohms ("H" position)
Output Level
(at 1,000 Hz)
-
"L"
"H"
Open Circuit Voltage*
PowerLevel**
. . . . . 84.0 dB -77.0 dB
(.063 mV) (.I41 mV)
. . . . . . . . . . . .
- 5 9 . 0 d B - 5 8 . 5 d B
*O dB = 1 volt per microbar
* * 0 dB = 1 milliwatt with 10 microbars
Switch
Built-in slotted Impedance-Off switch. May be used with tamper-proof cover or with accessory knob sup- plied. (See section on Switch Adapter Installation.)
Cartridge Shock Mount
Internal rubber vibration-isolator
Microphone Connector
Three-pin professional audio connector (male) de- signed to mate with Cannon XL series, Switchcraft
A3 (Q.G.) series, or equivalent connector
.
Swivel and Shock Mount Assembly
Positive action, permits tilting head through 180°, shock mounted with internal rubber vibration-isolator, suitable for mounting on stand with 548"-27 thread
Case
Satin-chrome plated die casting with stainless steel screen
Dimensions
See Figure 3
PHASING
To test two microphones and/or their cables for proper phasing, connect them to an amplifier and talk or sing into them while they are three to 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 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 micro- phone cable, either use a Shure Al5PR Phase Reverser or interchange the wires connected to pins 2 and 3 of the cable connector at one end of the cable only. To change the phase of a microphone, the microphone cartridge leads must be interchanged (see Figure 4).
This should be performed by your dealer, the Shure
Factory Service Department, or other qualified service personnel.
CARTRID*
-CODED TERMINAL
TRANSFORMER
YELLOW
5W1TCH PROFESSIONAL THREE-PIN
Am0 CONNECTORS
CABLE
<No7 OUWLlEDi
MALE
- -
POSITIVE PRESSURE
PIN
PRODUCES POSlTiVF VOLTAGE A l
2
W l m
RESPECT TO RN J
INTERNAL CONNECTIONS
FIGURE
4
FURNISHED ACCESSORY
Switch Knob Assembly
. . . . . . . . . . . . . . . . . . . .
.RK76S
OPTIONAL ACCESSORIES
Line Matching Transformer
Desk Stand
Windscreen
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vi bration-Isolation Stand
Quick Disconnect Adapter
Cable Connector (female)
. . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cable (6.lm [20 ftl with connectors)
. . . . . . . .
. . . . . . . . . . . . . . . . . .
A61 WS
.C50CN
RKIPOP
(ll/l6 IN.)
Cartridge
Swivel and Shock Mount Assembly
Plug Element
REPLACEMENT PARTS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Screen and Grille Assembly
Switch Assembly
Case Assembly
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .94A377
. . . . . . . . . . . . . . . . . . . . . . . . . . . . RK77C
. . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
R48
.RKI05P
34.9mm,/.
(I-3/8
IN.)
OVERALL DIMENSIONS
FIGURE
3
1 .I
17.5mm
(ll/l6lN.)
GUARANTEE
This Shure product is guaranteed in normal use to be free from electrical and mechanical defects for a period of one year from the date of purchase. Please retain proof of purchase date. This guarantee includes all parts and labor.
SHIPPING INSTRUCTIONS
Carefully repack the unit and return it prepaid to the factory. 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.
