Impedance Meter


The Minirator MR-PRO measures the impedance and power rating of distributed speaker systems. Deviations from the expected result identify problems such as bad connections, incorrect tap connections or short circuits. Use the optional 70 V / 100 V Protection Adapter for safe operation.

At a glance

  • Power & Impedance Measurement
  • 70/100 V Installations
  • Commissioning and maintenance

Impedance Testing with the Minirator MR-PRO

The impedance test supports the verification of distributed loudspeaker installations and shows detailed information of the connected load. The test result shows if the connected speaker system is in good order as well as the required amplifier power ratio. The power is automatically calculated by the measured impedance for 25 V, 35 V, 50 V, 70.7 V, 100 V, 140 V, 200 V systems.

Minirator MR-PRO Impedance Detail
Impedance and Phase

Minirator MR-PRO Power
Apparent Power and Phase


Detecting Installation Problems

The Minirator MR-PRO helps to detect problems, such as

  • Speakers not connected
  • Speakers wrongly connected
  • Connection to wrong transformer taping, e.g. 1 W instead of 2 W
  • Short circuits
  • Other external products, such as fire alarm devices connected
  • Bad connection cable

Advantage of MR-PRO Measurement Technology

Vibration and environment noise within the area of the speaker commonly effects the speaker impedance measurement results of other test instruments. The MR-PRO impedance measurement includes technology for achieving stable readings within noisy environments.

Measurement Hints

  • Disconnect the 100 V amplifier from the distributed speaker system prior to any measurements.
  • The typical test frequency is 1 kHz.

70 V / 100 V Protective Adapter for MR-PRO

70V/100V Protective Adapter for MR-PRO

Protects the Minirator MR-PRO against accidentally applied voltages during impedance or power testing at distributed 70V/100V speaker systems.

Product Data




MR-PRO Impedance Meter Kit

  • Minirator MR-PRO
  • 70 V / 100 V Protective Adapter
  • Mains Power Adapter
  • Exel System Case

Get more Information

Contact us for a quotation or to discuss your measurement application.

Request Quotation    Call now: +1 (503) 684-7050