HOW TO...
Measure Reverberation Time RT60
via an existing PA-System
QUICK GUIDE
This document provides a practical guide on how to use professional instruments to measure Reverberation Time RT60 in venues with existing Public Address systems used for evacuation and life
safety as well as general public announcements.
What you need:
• XL2 Audio and Acoustic Analyzer
• M4261 Measurement Microphone
• Minirator MR-PRO Signal Generator
• XLR Cable
Exel System Case with XL2 Audio and
Akustic Analyzer and Minirator MR-PRO
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4Oct 20 Page 1
QUICK GUIDEHow to measure Reverberation Time RT60
How to measure Reverberation Time RT60
Reverberation is one of the main acoustic characteristics of a room and influences speech intelligibility.
Connect the MR-PRO to a line
input of your system.
Measure with the XL2 in a
6 to 12 meter grid.
SETUP
On the MR-PRO, select GENERATOR from the main menu, click on WAV and select PNOISE, click
on MOD and select , then click on CYC and select 3/3s. *
On the XL2, select RT60 from the main menu, Run from the second menu, and 1/1 OCT resolution.
When the room is quiet, click SET.
This records the noise floor and sets the Level Markers
35dB above the noise floor in each frequency band.
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* If the RT60 values you measure are greater than the cycle time, increase the cycle time.
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QUICK GUIDEHow to measure Reverberation Time RT60
Play the cyclic PNOISE from the MR-PRO through your system. Adjust the gain of your system and your MR-PRO so
that there is enough energy to reach the top of the Level
markers in as many frequency bands as possible on the
XL2.
It is advisory to wear hearing protection.
Hint: You may have to increase the bass frequencies on your
system. Even so, it is often impossible to create enough energy in the 63Hz frequency band.
2. MEASURE RT60
On the XL2, press the Play button.
The status (STAT) changes to ARMED. Each time a cycle
is completed by the MR-PRO, the AVRG value increments.
Take at least 3 measurements ensuring that each frequency
band displays a tick mark after each measurement cycle
(except maybe the 63Hz band).
When the room is quiet, click SET.
On the XL2, press the Stop button.
On the MR-PRO, press the mute button.
On the XL2, select Res from the second menu. The RT60
results are shown.
Select CYC to review the results of each cycle and delete
cycles that are dissimilar.
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QUICK GUIDEHow to measure Reverberation Time RT60
Save the test.
3. CREATE AN RT60 REPORT
— Once all of your positions have been measured, connect your XL2 to your PC via USB and select
“Mass Storage” on the XL2.
— Open the Room Acoustics Reporter PC-software* and follow the Instructions.
* https://my.nti-audio.com/support/xl2/download/XL2-Room-Acoustics-Reporter.zip
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