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Can LMS Test.Lab measure RT60 times?

Creator
Creator

Want to measure RT60 times in a room.  Use a method with source shutoff.

2 REPLIES

Re: Can LMS Test.Lab measure RT60 times?

Siemens Phenom Siemens Phenom
Siemens Phenom

Hello,

 

Yes, we can do this in LMS Test.Lab in either Signature Acquisition (live measurement) or in Signature Throughput Processing (post processing).  See the community article that discusses this topic:  https://community.plm.automation.siemens.com/t5/Testing-Knowledge-Base/Sound-Absorption/ta-p/398589

 

Kevin

Re: Can LMS Test.Lab measure RT60 times?

Siemens Legend Siemens Legend
Siemens Legend

Here are a few more hints/directions for doing RT60 decay times (calculating the time it takes for a sound pressure to reduce by 60 dB) in LMS Test.Lab Signature:

 

  • Under ‘Tools -> Add-ins’ turn on ‘ANSI-IEC Octave Filtering’.  To control a sound source during the test, turn on “Source Control” as well.addin.png

     

  • To setup the source, in the ‘Acquisition Setup’ worksheet, turn on the source, set Signal Type to ‘Random’, and press ‘More’. White or pink noise can be set.source.png

     

  • In Channel setup, define microphone channels that are to be used for the RT60 calculation.
  • In ‘Online Processing’ worksheet, choose ‘Real-Time Octaves’ at the top of the worksheetoctave.png

     

  • Click on the reverberation tab in the middle of the ‘Online Processing’ worksheet.reverb.png

     

  • Some of these parameters are shown in the following diagram:

diagram.png

  • Key is that these settings allow RT60 times can be calculated based on projecting from a 20 dB or 30 dB reduction.

  • In the ‘Measure worksheet’ the source is now setup to stop running and create the reverberation decay.measure.png

     

 

  • When doing the measurement, the RT60 times are calculated for each octave band.  If the RT60 cannot be calculated for a particular octave band, the software will warn you, and the decay time for that band will be set to zero.