ARTA

Ok...ARTA is great but making me feel pretty dumb trying to set it up ��. Still Comparing ARTA with Clio Pocket with the included mic. ARTA is with the Steinberg UR22MKII and using a EMM6 mic (not currently running the calibration file for the mic). The correlation between the two systems is very good other than the SPL is off. What should I be checking to get SPL in line? I have the listed mic sensitivity loaded into both programs.
 

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I wrote this...

Hi Ivo,
Hope you are well. I think I have Arta calibrated, but for some reason when I am taking speaker impulse response, matter what output level is selected in the software, frequency response output is basically at the same level. Voltage from the amplifier does change and is audibly different. What am I doing wrong? Mic sensitivity is loaded also. Please see attached photo of Arta set to -10 and -20 output in the IR window settings. Thank you.
Erik

This was Ivo's response:

Hi,

It is expected behavior. You must differentiate two modes of measurements:



Level mode (like spectral analysis of level in STEPS) – it measure Level on system output 20Log(Uout). In this mode result depends on generator level.
Ratio mode (like frequency response FR1 and FR2 and IR) – it measure log ratio 10Log(Uout/Uin). In this mode result does not depends on generator level.


Best,

Ivo

Still not sure how to get a frequency response graph with true out put level. In Clio Pocket it's basically just point and shoot...I don't see why it's not that simple in ARTA. I'm sure I am missing something simple?
 
in arta and spectrum mode i get different spl reading depending on which resolution setting i choose, with higher resolution the spl drops down and this with constant output level, why is that?

In FFT Spectrum Analysis it is common to scale spectral components in dBV or PSD.

- PSD is Power Spectral Density normalized to 1Hz bandwith and it always gives spectral levels indenpendent on FFT size. It is normally used for analysis of wideband signals.

- In normal FFT mode (dBV or dBFS) spectral resolution depends on FFT Size (fr. resolution = sampling rate / FFT size). The larger FFT size can give smaller levels as they contain energy from smaller fr. band. This mode is generaly used for analysis of narrowband signal , like sine signal.

ARTA User Manual gives example of this modes.

Ivo
 
thanks, i will check the manual.

may i ask, is it possible, in the spa mode, not to start the generator automatically when clicking the rec button? i often use the spectrum analyzer for viewing external sounds and it is a bit annoying when arta keep starting the generator, it would be nice if this was user selected
 
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thanks, i will check the manual.

may i ask, is it possible, in the spa mode, not to start the generator automatically when clicking the rec button? i often use the spectrum analyzer for viewing external sounds and it is a bit annoying when arta keep starting the generator, it would be nice if this was user selected
Just select "External" for your signal source and the generator will not operate.

Dave.
 
yes, there it was, thank you! :)

by the way, do you know if it is possible to customize the average function? i would like to set how many samples to average, if i set average to 5 samples then measurement stops when it reaches 5, but i would like the measurement to keep running and just updating the graph for every new 5 samples of measurement
 
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yes, there it was, thank you! :)

by the way, do you know if it is possible to customize the average function? i would like to set how many samples to average, if i set average to 5 samples then measurement stops when it reaches 5, but i would like the measurement to keep running and just updating the graph for every new 5 samples of measurement
Setup.
Measurement.
Max Averages.

Dave.
 
I have tried that but the measurement stops after reaching the max average numbers that i have setted, i want the measurement to continue.

when i monitor a live event i would like to average maybe 3-5 samples and the measurement should continue until i press the stop button. like the expo average function but with user control of how many samples to average and in linear calculation
 
I have tried that but the measurement stops after reaching the max average numbers that i have setted, i want the measurement to continue.

when i monitor a live event i would like to average maybe 3-5 samples and the measurement should continue until i press the stop button. like the expo average function but with user control of how many samples to average and in linear calculation

For monitoring live events I recommend using third octave band analysis, (menu Tools->Third octave SPL) where you can set standard and arbitrary integration constant.
In Spectrum analyser mode you should use Exp averaging that uses 5 group of samples as base for averaging. By changing sample length and sampling rate you may adjust different integration time.

Ivo
 
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Joined 2018
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Question for those who bought an ARTA Licence key.

I am almost certain I bought an ARTA licence key over a year ago, but I cannot find it.

Does anyone know what email address the key would have come from so I can search my email for it?

I subscribed to this ARTA thread so I have LOTS of emails with "ARTA" in the header and body.

Thank you!

David.
 
Support page

First, I really like the ARTA software and thanks to Ivo and company for providing such a great tool.

And the manual is well written with a ton of information in it. However, I find myself some times in difficulty when I just want to "do something" in ARTA. I understand all the math and theory, and that info is great. But I don't do the math and theory on a regular basis, so I have to really read slow and think to understand and wrap my head around it.

The "what to do" information is buried in between many lines of math and theory. Again that's great information, but makes it difficult some times to just understand "what to do" to get a result you're looking for. Most times it's as simple as "go to this menu and set this," "go to this screen and set this," "set up your mic," hit the record button and you've got your measurement. No math needed, no understanding of the theory needed, just a result. In spite of all the math and theory, a frequency graph showing peaks and valleys, and understanding those, is not difficult for anyone to understand. Tweaking things to change/improve that are also not difficult for most people to understand.

So, for those who, like myself, long for better and more to the point information on "how to do" things in ARTA, please take a look at the documents on the support page, ARTA Support

I had not really been there before, so it was a discovery to find a few documents there that are better at "real world" use of ARTA, STEPS, and LIMP. Thanks for those! It could still be better, especially if there were some better videos, but there are some nice documents there.

gabo
 
Mic Calibration

I have not yet used a calibration file with ARTA, my mic is very flat and to this point I've mostly been learning how to use ARTA.

However, I am now ready to do some more detailed measurements, so I loaded my calibration file.

However, I'm getting some unexpected results. See the attached.

The first pic is the setup of my calibration with the boxes checked to use it.

The second pic is the FR with those settings.

The third pic is the FR with the two radio boxes unchecked so that it doesn't use the calibration files.

What am I doing wrong here? The only change for the two graphs was checking or unchecking the boxes in the frequency response calibration settings.

thanks, gabo
 

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When loading mic calibration file, if you calibration file contain unevenly distributed points at frequency axis, as is your case, please check the box "Show interpolated value ".
Then you will see two curves, one loaded and second calculated by interpolating values on frequencies of current FR.
You will probably see that in you case you have large differences at low frequencies. I've seen this behavior in several Earthworks calibration files, sent by users.
You can correct calibration file by loading it in some text editor and adding more dense frequency points. That will be give correct interpolation - with smallest differences from original file.

Ivo
 
ARTA Help Needed:
(1) When trying to create Directivity Patterns, I keep getting the error that "Error: this .pir file was made with newer version of ARTA!"
Please download ARTA software ver. 1.9.3 Update 1. to get correct .pir file reading.

@iMat,
I am getting this same error message when trying to use the “Load and Sum” feature in the Impulse Response Window even when using *.pir files created with Version 1.9.3.