Actual reverberation time and error from Pachyderm simulation

Hi all,
I'm currently working on calculating reverberation time using Pachyderm Acoustics.
I have a reverberation chamber close to me, and I have an environment where I can check the actual reverberation time.

The reverberation chamber of the attached GH file was given a condition of low sound absorption coefficient, and the reverberation time was simulated. (For example, the sound absorption coefficient of the plaster in the material library was set to 1% and analyzed.) )
Then, the reverberation time of Pachyderm's simulation showed a reverberation time of about 2 seconds in each frequency band, but this reverberation time was very different from the actual measured time. (In actual measurements, each microphone was approximately 125 Hz for 17.5 seconds, 250 Hz for about 14 seconds, 500 Hz for about 9.5 seconds, 1000 Hz for about 7.5 seconds, 2000 Hz for about 6.s, and 4000 Hz for about 3.5 seconds.) )
What are the possible causes?
I will attach the gh file so that you can check it and get an answer.

If the results of the respondent's analysis of the reverberation time in Pachyderm are similar to my measurements,
I would like to know the settings at that time.
Also, please let me know if there is any information required for verification

Thank you

Attachments:

question.gh, 21 KB

Replies to This Discussion

Permalink Reply by Arthur van der Harten on June 25, 2024 at 5:30am

Hi,
The main difference was that I used 25 percent scattering, and a 7 second cutoff time. That gave us a 3 second reverb time.

Can you confirm that the volume of your room is correct? Reverb times increases with volume, and your volume is very low. Are you sure it is correct?

I would love to help you more, but it's very difficult to help in this manner. I encourage you to email me at the nonprofit:

Info@orase.org

Maybe we can work under a non-disclosure agreement. It sounds like that would be better for you than doing this on a public forum.

Kind regards,

Arthur

Permalink Reply by FUYU on June 25, 2024 at 5:39pm