ARTA

ARTA 1.9.6

I am glad that you all help me in testing with different soundcards.
I will continue to analyze those small instability that mainly comes from soundcard driver transient; i.e. on first measurement, on change on sampling frequency, on change of soundcard etc.
(Some programs keeps driver open long before the measurement, and maybe that is way to go) .
Soon I will add measurement of longer PIR duration to enable measurement of T60 larger than 12s.
For those that downloaded ARTA 1.9.6. I recommend that you do it again, as I did not refreshed sweep start frequency in analysis of distortion.

Thanks,
Ivo
 
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To &JanRSmith:
sample position 300 is reference for zero time. It is chosen as modern sigma delta converter generate pre-ringing which we can treat as ringing in negative time. That is why we always have to put cursor bellow sample position 300. (Usually 30-60 samples bellow). This time shift givers proper magnitude response but adds additional phase shift (which can be compensated by setting as Time delay for phase calculation).

Ivo
 
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Ivo, thanks for adressing this. I ran into the same issue during loudspeaker measurements, resulting in what appears to be a DC offset in the impulse response in some measurements. I now have the latest ARTA installed, but I also have a lot of measurements done with the older versions so the DC offset is something that I need to deal with. Is there a way to remove it from existing measurements?
 
Hi @timpert , for existing measurements I would recommend processing your PIR files through VituixCAD IR to FR tool. It includes DC offset compensation, by taking an average of the first few samples of dead air in the file and shifting the IR by the offset to compensate.

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@DcibeL - I am considering the Motu M2 as a replacement for my Behringer. I am looking for a lower noise, lower distortion audio interface. This device would be used exclusively for making acoustic measurements with ARTA... Assuming the M2 has performance similar to your M4, would you recommend the Motu for use in ARTA?