Shure VR300 Datasheet

UNIDIRECTIONAL DYNAMIC MICROPHONE
2 2 2 HARTREY AVE
,
EVANSTON, IL, 6 0 2 0 4 U.S.A.
AREA CODE 3 1 21866-2200 CABLE: SHUREMICRO
.M.IOTII..O--LI
-.-...-
T W X : 9 1 0 - 2 3 1 - 0 0 4 8 TELEX. 7 2 - 4 3 8 1
M I C R O P H O N E S
AND
E L E C T R O N I C
COMPONENTS
I
GENERAL
This microphone is designed especially for use in com-
puter voice recognition applications. It is also suitable
for other uses such as paging, talkback, and other
communication-type applications where excellent voice
fidelity and reduction of background noises are needed.
DATA SHEET
MODEL VR300
A
The frequency response is tailored to produce an essen-
tially constant output voltage over the voice spectrum
when used close to the sound source. The transducer is
a low-impedance, moving coil type with integral hum-
bucking coil.
m
The microphone case is aluminum with a black enam-
eled finish. It has a standard 5/a"-27 thread suitable for
mounting on a flexible gooseneck, fixed pipe, or micro-
phone stand. The unit is supplied with an attached
two-conductor shielded cable with a built-in strain
relief.
SPECIFICATIONS
m
-
+I0
Z
-
W U 1
:
0
3
W
$
-10
W
20
50
100 1,000 l 0 ,OOO 20,000
FREOUENCY IN HERTZ
*Distance from lips to microphone grille
TYPICAL FREQUENCY RESPONSE
FIGURE 1
Impedance
170 ohms actual
Output Level
Open Circuit Voltage*
. . . . . . . . . . .
-41.0 dB (8.9 mV)
Power Level**
. . . . . . . . . . . . . . . . .
-59.5dB
* O dB
=
1V1100 @bar
* * 0 dB
=
1 mWI10 ybar
Phasing
Positive pressure on diaphragm produces positive
voltage on white conductor with respect to black
conductor (see Figure 2)
VOICE HUMBUCKING CABLE
COIL COIL
,-,---------
-
[,r
;
BLACK
T i ;
-I
WHITE
I
-
-
- - - - - - -
:
SHIELD
=,
INTERNAL CONNECTIONS
FIGURE 2
Hum Pickup
Maximum 15 dB equivalent SPL in 1 mOe field
Cable
1.2m (4 ft) two-conductor shielded
Case
Aluminum with black enameled finish; stainless
steel screen
Dimensions
See Figure 3
Net Weight
128 grams (4.5 oz)
OPERATION
To obtain the best performance with the VR300, the
microphone must be used in a close-talking manner.
Type
The lips should be as close to the microphone grille as
--Dynamic, Unidirectional (cardioid), Close-Talking
comfort permits, with a distance of 1 to 5 cm (0.4 to 2 in.)
Frequency Response
100 to 7,000 Hz (see Figure 1)
providing the greatest discrimination between voice
and background noise.
C o p y r ~ g h t 1982, Shure Brothers Inc
27A8048 (BL)
P r ~ n t e d
In
U.S.A.