Audio Technica PRO 31QTR Specifications Download Page 1

O N

O N

O N

OFF

Fig. 1a

Fig. 1b

Fig.1c

Fig. 1d

Do 

not

try

Do 

not

turn

to lock switch

Unlocked

Locked

screw clockwise

in the “off ”

Position

Position

to lock

position

SCALE IS 5 DECIBELS PER DIVISION

Polar Pattern

200 Hz

LEGEND

5 kHz

1 kHz

8 kHz

240

180

210

270

300

330

0

150

120

90

30

60

12" or more on axis

s

100

50

200

LEGEND

D

10k

5k

1k

500

2k

20k

Frequency in Hertz

Frequency Response

Response in dB

10 dB

• Designed for close-up vocal use

• Silent on-off operation thanks to MagnaLock

switch design

• Hi-ENERGY

®

neodymium magnet for improved output and 

transient response

• Two-stage ball-type screen reduces wind noise and “popping”

during close use

• Corrosion-resistant contacts from gold-plated XLRM-type 

connectors

• Rugged design and construction for reliable performance

• Cardioid polar pattern reduces pickup of sounds from the sides 

and rear, improving isolation of desired sound source

Output from the microphone’s XLRM-type connector is low 
impedance (Lo-Z) balanced. The signal appears across Pins 2 and
3; Pin 1 is ground (shield). Output phase is “Pin 2 hot” – positive
acoustic pressure produces positive voltage at Pin 2.

When using the PRO 31QTR in settings with a stage monitor
speaker, the speaker should be located 180° off axis (at the rear 
of the microphone). This placement, in conjunction with the 
microphone’s uniform cardioid pickup pattern, will virtually eliminate
the possibility of undesired audio feedback.

The PRO 31QTR utilizes a MagnaLock on/off switch. This specially
designed switch operates silently and may be locked in the “on”
position to prevent accidental turn-off during use. To lock, slide the
switch up into the “on” position (Fig. 1a). Using a small flat-head
screwdriver, rotate the small screw in the center of the switch 90
degrees (

1

/

4

turn) counter-clockwise (Fig. 1b). Never force the screw.

When the screw slot position is horizontal (“across” the microphone
body), the switch is locked. To unlock the switch, turn the screw 90
degrees clockwise until the screw slot position is again vertical (in
line with the microphone body). Never try to turn the switch more
than 90 degrees or 

1

/

4

rotation. The switch may only be locked in the

“on” position. Do not try to turn the screw when the switch is in the
“off” position.

Take care to keep foreign particles from entering the windscreen.
An accumulation of iron or steel filings on the diaphragm, and/or
foreign material in the windscreen’s mesh surface, can degrade
performance.

Audio-Technica U.S., Inc., 

1221 Commerce Drive, Stow, Ohio 44224

Audio-Technica Limited,

Old Lane, Leeds LS11 8AG England

www.audio-technica.com

P3893-00181     P51678-EN     ©2004  Audio-Technica U.S., Inc.    Printed in Taiwan

PRO 31QTR 

CARDIOID DYNAMIC MICROPHONE

PRO 31QTR SPECIFICATIONS

ELEMENT

Dynamic

POLAR PATTERN

Cardioid

FREQUENCY RESPONSE

60-13,000 Hz

OPEN CIRCUIT SENSITIVITY

–55 dB (1.7 mV) re 1V at 1 Pa*

IMPEDANCE

600 ohms

SWITCH

MagnaLock

on/off

WEIGHT 

(less cable and accessories)

11.0 oz (312 g)

DIMENSIONS

7.28" (185.0 mm) long, 
2.09" (53.1 mm) head diameter

OUTPUT CONNECTOR

Integral 3-pin XLRM-type

CABLE 

15.0' (4.5 m) cable with XLRF-type 
connector at microphone end, 

1

/

4

" connector at equipment end

ACCESSORIES FURNISHED 

AT8470 Quiet-Flex

stand clamp for 

5

/

8

"-27 threaded stands;

5

/

8

"-27 to 

3

/

8

"-16 threaded adapter;

soft protective pouch

†In the interest of standards development, A.T.U.S. offers full details on its test 

methods to other industry professionals on request.

*1 Pascal = 10 dynes /cm

2

= 10 microbars = 94 dB SPL

Specifications are subject to change without notice.

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