Dayton Audio iMM-6 microphone calibration problem. Cannot read from SD card

[Demir Döken]

Hi,

I have purchased Dayton Audio iMM-6 microphone recently and tried to load the calibration file as instructed by copying the downloaded calibration file(extension changed to cal) to the Audiotool directory in my S3 device2s sdcard0 memory. When I try to load the calibration file Audiotool shows the file name as 99-00157 however when I tap on the file name  software gives a message "Cannot read from SDcard". 

I have tried storing couple of spectrum and loading. I can load the saved spectrum without ant problems which the files are saved in the same directory.

I have also tried re installing Audiotool however I am still facing the same problem. I am currently using v.5.8.2.

Can anyone please help me with this problem?

Thanks in advance

[Julian Bunn]

This is odd: I'm not sure what is going wrong. Are you able to Store and then Load a standard AudioTool calibration file? The error message indicates that either the AudioTool directory doesn't exist on the SD card, or the SD card cannot be read, or there is a problem with the Dayton file itself. I suspect the latter as most likely. (I hope Dayton haven't changed their file format!)

Please email me your Dayton .cal file and I will check it here.

Julian

--
You received this message because you are subscribed to the Google Groups "AudioTool Discussion Group" group.
To unsubscribe from this group and stop receiving emails from it, send an email to audiotool-discussio...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.
 
 

[Demir Döken]

Hi Julian,

Problem solved. At first I have changed the extension of the calibration file at windows and than copied it to mt s3 device, doing so I was getting the read error message that I have mentioned. 

I tried changing the extension of the calibration file in my s3 device via OI file manager. Now I can load the calibration file at least I assume so because software does not give any error message when I tap on the calibration file name but it doesn't give a confirmation message indicating calibration file loaded or such either.

I have a earthworks m23 microphone and a sound level calibrator which I use for acoustic measurements together with ARTA software. I have set my system and performed some simultaneous measurements to see the accuracy of the IMM-6 with auditotool. 

I have expected similar results since the IMM-6 microphone is calibrated however I am getting 15-16 dBA higher reading with IMM-6 with respect to the calibrated system. I have also tried directly connecting the sound level calibrator to the IMM-6 microphone using the earhworks microphone's adapter. readings are similar I am getting 110 dB on 94 dB  calibration signal at 1 kHz.

I haven't used the calibrator for a long time maybe for 2 years therefore I cannot be 100% sure about the accuracy of the system but there is no way that It is 16 dB off.

I assume calibration file dayton is providing is for setting the response to a flat sound pressure level within frequencies however it does not provide calibration for sound pressure level measurements. Do you have any information regarding this issue?

Once again I have to say I cannot be 100% sure about the accuracy of the calibrator since its been lying in the closet for a long time. I would appreciate if someone can try such measurement and share the results with us.

Thanks 

2013/5/3 Julian Bunn <jjb...@gmail.com>

--
You received this message because you are subscribed to a topic in the Google Groups "AudioTool Discussion Group" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/audiotool-discussion-group/fSbC0SD7L7o/unsubscribe?hl=en.
To unsubscribe from this group and all its topics, send an email to audiotool-discussio...@googlegroups.com.

[Julian Bunn]

Hi Demir,

Thanks for the update.

"I assume calibration file dayton is providing is for setting the response to a flat sound pressure level within frequencies however it does not provide calibration for sound pressure level measurements. Do you have any information regarding this issue?"

This is exactly right - the Dayton files contain an absolute offset value for the overall Mic response. It refers to the sensitivity of the mic capsule relative to the IEC 60268-4 standard reference level of 10mV/Pa at 1kHz. 

The rest of the file, which is what is used in AudioTool, gives per-frequency dB offsets from flat.

I have no way, in AudioTool, of using the mic sensitivity, as the amplification level of the electronics in each phone model can (and will be) different.

Thus, using your piston phone calibrator, I think you need to 

a) load the Dayton file into AudioTool,

b) go into 1/3 octave cal mode

c) apply the calibrator

d) adjust each 1/3 octave level *by the same amount* so that the overall dB SPL matches the calibrator

e) Save the revised calibration

Others more expert than I am on calibration might like to correct me if this is wrong!

One feature I could add to AudioTool to make this easier is to use the "Single Value" calibration value as a global correction in the 1/3 octave mode. Or simply add a means of entering a global offset.

Julian

[audio...@gmail.com]

Julian,

What exactly does the cal file do?  Does it call the mic or the phone based on what phone you have?

2013/5/3 Julian Bunn <jjb...@gmail.com>

Julian

To unsubscribe from this group and stop receiving emails from it, send an email to audiotool-discussion-group+unsub...@googlegroups.com.

For more options, visit https://groups.google.com/groups/opt_out.
 
 

--
You received this message because you are subscribed to a topic in the Google Groups "AudioTool Discussion Group" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/audiotool-discussion-group/fSbC0SD7L7o/unsubscribe?hl=en.

To unsubscribe from this group and all its topics, send an email to audiotool-discussion-group+unsub...@googlegroups.com.

For more options, visit https://groups.google.com/groups/opt_out.
 
 

--
You received this message because you are subscribed to the Google Groups "AudioTool Discussion Group" group.

To unsubscribe from this group and stop receiving emails from it, send an email to audiotool-discussion-group+unsub...@googlegroups.com.

[Julian Bunn]

The cal file is used to adjust the calculated dB levels at all frequencies - if the cal file has for example a value of -3dB at 1000Hz, then AudioTool will show 3dB less at 1000Hz compared with what it would show if the cal file wasn't loaded.

Of course, even with a perfectly flat response microphone (i.e. all corrections are 0dB), if the phone's internal electronics have a none-flat frequency response, then you will still see the effect of that. Ideally, the best results would be obtained by calibrating the combination of microphone (whether external or built-in) and phone. 

That's why having contributed cal files from AudioTool users who have the means to perform such calibrations is so valuable. Unfortunately I don't have the resources myself to do this (when you consider the number of different Android phones and tablets on the market, plus the number of different external mics, plus the variations from one Android firmware version to another that can affect audio, it's a daunting combinatorial proposition!).

Julian 

To unsubscribe from this group and stop receiving emails from it, send an email to audiotool-discussio...@googlegroups.com.

[rtsun...@gmail.com]

I'm seeing this issue now on my Nexus 4.

Downloaded the .txt file from Dayton on my device... renamed it to .cal and dropped it into the AudioTool directory on my SD card.  When I try to load the file, I get the error message.  Tried redownloading the file, same nonsense.  I've attached the .cal file for reference.

[Julian Bunn]

I'm wondering whether another App is running that has a read/write lock on the SD card. If you re-start the Nexus, does the problem remain? Are you running an App like OI File Manager at the same time as AudioTool? Are you able to Store and Load a spectrum file in the RTA mode (which also writes/reads from the SD card)?

Julian

On Mon, Sep 9, 2013 at 10:13 PM, <rtsun...@gmail.com> wrote:

I'm seeing this issue now on my Nexus 4.

Downloaded the .txt file from Dayton on my device... renamed it to .cal and dropped it into the AudioTool directory on my SD card.  When I try to load the file, I get the error message.  Tried redownloading the file, same nonsense.  I've attached the .cal file for reference.

[teaja...@gmail.com]

I am having this same problem. SGS2 with version 6.2.3. I can save a spectrum but I can't seem to recall it yet. I use AirDroid to load the .cal on my phone....which goes to the SD card (not external SD). On my phone, if I go into "My Files" and tap on the file, a message is given that there is no available app to open it (whether the .cal file or the saved .at file).

    TIA, Tom

[Julian Bunn]

Hi Tom,

.at files are to be opened within AudioTool, via the "Load" button on the main screen.

.cal files are opened via the Menu, after you have set "1/3 octave calibration" (also via the Menu).

For the .cal files, ensure that they really do end in ".cal", and not e.g. ".cal.txt"!

Hope this helps,

Julian

--
You received this message because you are subscribed to the Google Groups "AudioTool Discussion Group" group.
To unsubscribe from this group and stop receiving emails from it, send an email to audiotool-discussio...@googlegroups.com.

For more options, visit https://groups.google.com/d/optout.

[ThomasJ Smit]

I think I have the "Load" part figured out. As per the threads and instructions,  I did try your suggestion about the ".cal" and not ".cal.txt", and the "1/3" selection before I posted the problem. If I read the file name in "My files", it reads ".cal"; however, when going to "Menu", and then "Load Cal", it only shows the  serial number but the  ".cal" does not show.

--
You received this message because you are subscribed to a topic in the Google Groups "AudioTool Discussion Group" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/audiotool-discussion-group/fSbC0SD7L7o/unsubscribe.
To unsubscribe from this group and all its topics, send an email to audiotool-discussio...@googlegroups.com.

[Julian Bunn]

This sounds like correct behaviour :-) In the Load Cal list, the file suffix is not shown.

Julian

[ThomasJ Smit]

Heh, that's good to know! At least that, too, is operating correctly. So, the only l

thing left is to figure out why I get "Cannot read from SD" when I select the .cal file. Is that correct behaviour? I don't know.

   Thanks.

[Julian Bunn]

No, that indicates there is a problem with the file being read. Can you send your .cal file to me in email?

Julian

[ThomasJ Smit]

Sent

[ThomasJ Smit]

The owner, Julian, emailed me directly and suggested that I should try the ".cal" file that he sent. I tried it and it worked! So, what I did then was, I went back to Dayton Audio and down-loaded the calibration file exactly as was directed to, (I think I may have previously made an error in the steps). I then transferred it from my laptop via AirDroid and had success.

    Thank you, Julian,  very much for your time, and patience!

   Tom

[Julian Bunn]

Tom,

Good to hear you were able to fix the problem. I still can't see anything wrong with your original file, so that remains a mystery!

Julian

[ThomasJ Smit]

Okay. Like I just posted, I followed the directions exactly. What that means is that I did it wrong the first time, silly me, which is, I wrongly down-loaded the ".txt" file onto my laptop, and then  renamed ".cal". Then I uploaded that renamed file to my phone. Duh!

After you sent me the temporary test file and I found that it worked for me, I went back to DaytonAudio to get another file, and renamed the ".txt" file to ".cal" before I down-loaded.

I have selected the calibration on my phone and I can see the serial number under the graph.


Again, much thanks!

   Tom

[Sample Guru]

Hello Julian,

Great app with the Dayton IMM-6 mic. Loaded your .CAL file and works fine, I understand that it cannot be the 'ideal' setting with all the different brands of phones and android versions. However I have one question, after loading your .CAL file, do I have to put in a number in the set cal. offset (this will be different for each phone) or can I leave it and just use your app and will have 'good' callibrated results ?

Thank you and keep up the good work.

Best regards Aart from the netherlands

2013/5/3 Julian Bunn <jjb...@gmail.com>

Julian

To unsubscribe from this group and stop receiving emails from it, send an email to audiotool-discussion-group+unsub...@googlegroups.com.

For more options, visit https://groups.google.com/groups/opt_out.
 
 

--
You received this message because you are subscribed to a topic in the Google Groups "AudioTool Discussion Group" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/audiotool-discussion-group/fSbC0SD7L7o/unsubscribe?hl=en.

To unsubscribe from this group and all its topics, send an email to audiotool-discussion-group+unsub...@googlegroups.com.

For more options, visit https://groups.google.com/groups/opt_out.
 
 

--
You received this message because you are subscribed to the Google Groups "AudioTool Discussion Group" group.

To unsubscribe from this group and stop receiving emails from it, send an email to audiotool-discussion-group+unsub...@googlegroups.com.

[Julian Bunn]

Hi Aart,

Ideally you would set the global offset so that the dB SPL reading for a broadband signal (e.g. Pink Noise) matches that from a third party SPL meter. That will then take into account both the Dayton cal curve and the absolute value adjustment. However, if you don't have access to an external meter, the default global calibration is perhaps good enough, unless you are doing very critical measurements.

Julian

2013/5/3 Julian Bunn <jjb...@gmail.com>

Julian

To unsubscribe from this group and stop receiving emails from it, send an email to audiotool-discussio...@googlegroups.com.

For more options, visit https://groups.google.com/groups/opt_out.
 
 

--
You received this message because you are subscribed to a topic in the Google Groups "AudioTool Discussion Group" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/audiotool-discussion-group/fSbC0SD7L7o/unsubscribe?hl=en.

To unsubscribe from this group and all its topics, send an email to audiotool-discussio...@googlegroups.com.

For more options, visit https://groups.google.com/groups/opt_out.
 
 

--
You received this message because you are subscribed to the Google Groups "AudioTool Discussion Group" group.

To unsubscribe from this group and stop receiving emails from it, send an email to audiotool-discussio...@googlegroups.com.

For more options, visit https://groups.google.com/groups/opt_out.
 
 

--
You received this message because you are subscribed to the Google Groups "AudioTool Discussion Group" group.

To unsubscribe from this group and stop receiving emails from it, send an email to audiotool-discussio...@googlegroups.com.
To post to this group, send email to audiotool-dis...@googlegroups.com.
Visit this group at https://groups.google.com/group/audiotool-discussion-group.
For more options, visit https://groups.google.com/d/optout.