Minirator MR-PRO / MR2

Compact. Indispensable. Portable.

  • Analog Audio Generator
  • Impedance Meter (MR-PRO)
  • Cable Tester (MR-PRO)

Accessories Applications Technical Data

The Minirator MR-PRO provides a full set of analog audio signals including sine wave, pink noise, white noise, delay test signal, polarity test signal, stepped sweep and continuous sine sweep. Further, a set of wav-files, useful for system optimization, is stored in the internal flash memory. Add your own personal favorites to this set.

At a Glance

  • Sine Test Signals
  • Frequency Sweeps, Chirps
  • Pink Noise, White Noise


Besides the broad range of generated audio signals, the Minirator MR-PRO monitors the signal balance, phantom power and impedance of the connected load. An integrated XLR cable tester simplifies trouble shooting tasks.

The workhorse MR2 provides all the basic standard signals at an attractive price point. Both generators are indispensable and proven tools for set-up, maintenance and monitoring of all types of audio equipment.

Test Signals


Minirator generates pure sine waveforms at user-selectable frequencies and amplitudes. The frequency steps interval can be set to as low as 0.1Hz.

  • Selectable frequencies from 10 Hz to 20 kHz
  • Level range from -80 to +18 dBu

MR-PRO screen Sine


The start/stop frequency, step time and a step resolution as fine as 1/12th octave can be adjusted. Audio analyzers automatically trigger to this signal and record the frequency response of a device under test.

MR-PRO screen Sweep


The chirp signal is a logarithmic or linear gliding sine sweep signal with continuous frequency increase over time. Typical applications are recording of frequency responses, impulse response measurements and acoustic assessment of rooms.

MR-PRO screen Chirp

Delay Test Signal

This is the designated reference signal to measure the acoustic propagation delay time from speaker to speaker in e.g. churches or auditoriums. It suits the accurate setup of delay line arrangements, thus the directionality of the signal source will be optimized. Testing is carried out in combination with the XL2 Audio and Acoustic Analyzer.

MR-PRO screen Delay

Pink & White Noise

Pink or white noise is synthesized with high spectral density, normal amplitude distribution and with infinite cycle duration. The Minirator also generates gated pink noise (on/off cycle 1 - 9 seconds) for convenient RT60 measurements with the XL2 Audio and Acoustic Analyzer.

MR-PRO screen White-Noise


Test signal for measuring the polarity of speakers and audio signals. The saw-tooth waveform is an ideal stimulus with only moderate stress to speakers. Testing is carried out in combination with the XL2 Audio and Acoustic Analyzer or Minilyzer ML1.

MR-PRO screen Polarity

User Wav-Files *.wav (MR-PRO only)

The Minirator MR-PRO offers a range of additional factory test files, e.g. for speech intelligibility verification. You may store additional user test signals as uncompressed wav-files in the MR-PRO memory. The selected file is seamlessly looped. Wav-file exchange is simplified via the USB port.

  • Pre-installed: STIPA, Voice, Music
  • User downloads at the support page:
    • Third- and Octave Pink Noise
    • Square Wave: 10 Hz - 5 kHz
    • Sine: 1 Hz - 10 Hz
    • Power Test acc. IEC60268-5
    • NormSignal acc. EN60065
    • Cinema Headroom Test

MR-PRO screen WAV-File

More Minirator MR-PRO Functions

Measurement Functions in Generator Mode

Providing a detailed view of the connected load for rapid fault finding

  • XLR Signal Balance
  • Load Impedance
  • Phantom Power Voltage

Minirator MR-PRO Impedance

Cable Test

The MR-PRO verifies the correct XLR cable wiring, detecting all common XLR wiring faults with a precise description, such as “2-3 Crossed” or “Pin 2 open”. Additionally an optional Cable Test Plug may be used for single ended installations.

Minirator MR-PRO Cable Test

Impedance and Power Test

MR-PRO measures the impedance, phase and power rating of distributed speaker systems at selectable frequencies. The following parameters of the connected load are shown:

  • Impedance and Phase
  • Apparent Power and Phase

Minirator MR-PRO Impedance Detail

Minirator MR-PRO Power

Store Preset Configurations

Up to 10 complete instrument configurations can be stored in the internal flash memory and reloaded for repetitive tasks. The saved settings may also be transferred to other MR-PRO instruments.

Compensated Output Stage

The output level corresponds over a wide range of loads to the set output voltage compensating the output impedance of the generator. Possible maximum limits when reaching the output current limit are clearly indicated.

MR-PRO or MR2?

The Minirator is available as the powerful MR-PRO Audio Generator or the basic MR2.


  • Output Level maximum
18 dBu 8 dBu
  • Flatness
+/- 0.2 dB +/- 0.5 dB
  • Output Impedance
12.5 Ω 200 Ω
  • THD+N typical
< -96 dB < -90 dB
Measurement Functions    
  • Phantom Power
  • Impedance and Phase
  • Apparent Power and Phase
    (for 70V/100V distributed loudspeaker systems)
  • Signal Balance
  • XLR Cable Tester
Test Signals    
  • Sine, Sweep and Chirp
  • Pink Noise, White Noise
  • Polarity and Delay
  • User Wav-Files (*.wav)
Configurations Storage -
Protective Shock Jacket  -
Hand Strap, USB Cable


Minirator Audio Signal Generator

Minirator MR-PRO

Professional Audio Signal Generator
NTi Audio #: 600 000 310

Minirator MR2

Basic Audio Signal Generator
NTi Audio #: 600 000 300

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