General Description

The Model 522 is a dynamic base-station microphone for radio communications, paging, and dispatching systems. Its cardioid (unidirectional) pickup pattern suppresses unwanted background noise from nearby dispatchers, ventilating equipment, or office machines. It also can reduce feedback in public address paging applications.


  • Dual impedance (19 to 300 ohms or High)
  • Impedance change switch for convenient change-over
  • Finger-tip control bar (locking or non-locking action) to actuate microphone circuit and an external relay or control circuit
  • Long-life swtich to satisfy rigorous requirements of communications and paging systems
  • Sturdy, high impact ARMO-DUR®, base and microphone case
  • Adjustable microphone height
  • Dependable under most operating conditions

Press-To-Talk Switch Operation

Press and hold the bar switch to talk. To lock the switch, press and pull it forward. To unlock the switch, move the bar back and release.

Impedance Selection

Use the switch located under the microphone base, near the cable entry, to select high (HI) or low (LO) impedance.

Use the low-impedance position for long cable lengths under conditions of severe hum disturbance. Use Shure Model A95 Series Line Matching Transformers when using a low-impedance microphone line with a high-impedance amplifier input.

Logic Connections

The RED and BLACK leads may be used to control an external relay or switching circuit.

Audio Connections

Unbalanced high-impedance operation:

Set the impedance switch to the HI position (as shipped). Connect the GREEN cable lead and the shield to the amplifier chassis ground. The WHITE cable lead is the "hot" conductor.

Balanced-line low-impedance operation:

Set the impedance switch to the LO position. Connect the shield to the amplifier chassis ground. The WHITE and GREEN cable leads are the "hot" conductors.

Cable-to-Connector Wiring
Input Type Wire Color Function XLR Connector 1/4 in. Phone Plug
Unbalanced White Audio Pin 2 Tip
Green Audio Ground Pin 3 Sleeve
Shield Chassis Ground Pin 1 Sleeve
Balanced White Audio + Pin 2 Tip
Green Audio - Pin 3 Ring
Shield Chassis Ground Pin 1 Sleeve



Dynamic (moving coil)

Frequency Response

60 to 11,000 Hz

Polar Pattern


Output Impedance

Dual. "Low" is 260 ohms for connection to microphone inputs rated at 19 to 300 ohms and "High" for connection to high-impedance microphone inputs.


at 1kHz, open circuit voltage, dependent on impedance setting

LOW -57.5 dB (1.3 mV)
HIGH -38.5 dB (12 mV)[1]


Press-to-Talk Switch lockable, for microphone and an external relay or control circuit. Microphone circuit normally shorted in both high and low impedance.
Impedance Selection Switch provides either high- or low-impedance operation.

Cartridge Shock Mount

Internal rubber vibration isolator


2.1 m (7 ft) four-conductor, two conductors shielded non-detachable


Two-tone gray ARMO-DUR, with dull-chrome-plated steel screen


736 g (1 lb 10 oz.)

[1]1 Pa = 94 dB SPL

Typical Polar Pattern

Typical Frequency Response

Overall Dimensions


Replacement Parts

Cable C31C
On-Off Switch K141S


This product meets the Essential Requirements of all relevant European directives and is eligible for CE marking.

The CE Declaration of Conformity can be obtained from:

Authorized European representative:

Shure Europe GmbH

Headquarters Europe, Middle East & Africa

Department: EMEA Approval

Jakob-Dieffenbacher-Str. 12

75031 Eppingen, Germany

Phone: +49-7262-92 49 0

Fax: +49-7262-92 49 11 4