Experimental - changes to DMR speaker level

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VK3KYY
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Experimental - changes to DMR speaker level

Post by VK3KYY » Thu Jan 16, 2020 2:49 am

I've had several requests about increasing the DMR speaker level, and potentially dynamically controlling its level,

I've looked in the data sheet, (thanks to Colin G4EML for extracting the details of the control registers from the data sheet on the C6000) and the DMR line output control appears to have settings from 0dB to 6dB and is normally set to 2dB, because this is the value used by the official firmware.

However, I have tried changing the line output to 6dB, and I think it may be making the audio a bit louder.

Its hard to do a objective test, without running 2 GD-77's connected to an oscilloscope, but it definitely doesn't sound any worse than before.

Note.
This version also uses the 1 DMR frame delay in the audio, as from feedback from yesterday's experimental version the 1 frame delay seems to improve the audio quality
Attachments
OpenGD77_20200161328_lineout_gain_6db.sgl
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n7rde
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Re: Experimental - changes to DMR speaker level

Post by n7rde » Thu Jan 16, 2020 3:19 am

Thanks - I did a quick test and it seems to help

Ron

VK3KYY
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Re: Experimental - changes to DMR speaker level

Post by VK3KYY » Thu Jan 16, 2020 3:37 am

n7rde wrote:
Thu Jan 16, 2020 3:19 am
Thanks - I did a quick test and it seems to help

Ron
Hi Ron,

OK.

Its a bit hard to tell, but in theory the sound should be 4dB louder, i.e just over x times as much signal level, but I know the human ear's audio response is non-linear, so 4dB will not be much of an increase.

DJ0HF
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Re: Experimental - changes to DMR speaker level

Post by DJ0HF » Thu Jan 16, 2020 9:36 am

I thought the fact the GD77 sounded quieter than I remembered was just me but the change to +6db works really well. Many thanks
Ian

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Re: Experimental - changes to DMR speaker level

Post by VK3KYY » Thu Jan 16, 2020 9:38 am

DJ0HF wrote:
Thu Jan 16, 2020 9:36 am
I thought the fact the GD77 sounded quieter than I remembered was just me but the change to +6db works really well. Many thanks
Ian
Can you also try the latest version.

https://www.opengd77.com/viewtopic.php? ... 85c2887e71

It has this change and some other optimisations, but some people reported a problem with the 'latest'

DJ0HF
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Re: Experimental - changes to DMR speaker level

Post by DJ0HF » Thu Jan 16, 2020 10:42 am

Have tried the Latest version and it works fine on my GD77 in both FM and DMR modes and changing the Beep level to 0db or -3db doesn't cause any problems at all here, which I think some people may have reported.
Ian

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Re: Experimental - changes to DMR speaker level

Post by VK3KYY » Thu Jan 16, 2020 10:47 am

Ok...

Changes to volume only affect DMR as the audio path is completely different to the FM audio

DJ0HF
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Re: Experimental - changes to DMR speaker level

Post by DJ0HF » Thu Jan 16, 2020 2:53 pm

VK3KYY wrote:
Thu Jan 16, 2020 10:47 am
Ok...

Changes to volume only affect DMR as the audio path is completely different to the FM audio
Okay, I only use the GD77 on DMR so I only quickly checked that FM was also still working with the latest firmware just to be on the safe side.
Ian

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