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TOPIC: Discrepancy--88A User Guide and DLCT Help Screen

Discrepancy--88A User Guide and DLCT Help Screen 1 year 7 months ago #19052

  • AustinJerry
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There are completely different instructions regarding the proper procedure to set output levels on the test tone screen in the DLCT. The Help Screen shows this instruction:



Yet, the current version of the user guide says this:



If one follows the Help Screen procedure, the resulting output level is approximately 20dB lower than if one follows the User Guide procedure.

Kindly clear up this confusion by recommending which procedure is correct, and then fixing the discrepancy in the documentation.

Thanks.
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Discrepancy--88A User Guide and DLCT Help Screen 1 year 7 months ago #19068

  • john.reekie
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What probably happened there was that the firmware and manual was updated and the Help text was overlooked.

Jerry, you do measurements all the time, right? Which of the two procedures result in acoustic level closer to what you would normally use for measurements?
I am not miniDSP support.

"You must ask the right questions." - Dr. Alfred Lanning's hologram.
-> Have you read the User Manual??
-> Have you drawn and posted a diagram?
-> Have you posted a screenshot?
-> Have you posted your config file?
Last Edit: 1 year 7 months ago by john.reekie. Reason: spel
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Discrepancy--88A User Guide and DLCT Help Screen 1 year 7 months ago #19072

  • AustinJerry
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Yes, John, I have done a fair number of calibrations as my listening room undergoes changes. I have always followed the procedure outlined in the User Guide. My output volume is normally -35dB (nice that the most recent DLCT update now provides a level indicator), and the input gain is right about zero. Following a calibration, my speaker levels, measured with REW, are all essentially the same at 76dB, including the sub channel. I consider this very accurate results.

I have never tried the approach shown in the in-app Help Screen. It was called to my attention by a fellow participant in the 88A thread on AVS Forums. Since I have not actually tried the other method, I cannot comment on the resulting speaker levels. I am concerned that the output level is resulting in a lower S/N ratio for the calibration. In discussions in the AVS thread, most users have indicated that they are using the "User Guide" approach.
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Discrepancy--88A User Guide and DLCT Help Screen 1 year 7 months ago #19073

  • john.reekie
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HI Jerry, thanks. As I recall the earlier firmware had much lower gain on the mic input.
I am not miniDSP support.

"You must ask the right questions." - Dr. Alfred Lanning's hologram.
-> Have you read the User Manual??
-> Have you drawn and posted a diagram?
-> Have you posted a screenshot?
-> Have you posted your config file?
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Discrepancy--88A User Guide and DLCT Help Screen 1 year 7 months ago #19083

  • devteam
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@ Jerry,

It's a good question indeed and we never noticed that before actually.. I wonder why the Dirac team suggested that path..
At a first glance it doesn't make much sense (i.e. artificially raising the signal from the UMIK-1). The system would have higher chance to run close to the overall noise floor (both acoustic of the room and electrical) is what comes to mind to us.. But once again we're maybe missing something. We'll ask the Dirac team the reasoning behind it and will get back to you.

Since quite a few of you (and our team as well) have been successful with our recommended user manual method, I'd say we keep to this for now on..

DevTeam
MiniDSP, building a DIY DSP community one board at a time.
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