[arm-allstar] How to adjust the audio characteristics for both TX and RX?

[Doug Crompton]

Irvin,

  Not sure what you  mean by "what script is called out" ?  The
pre/deemphasis routines are fixed and not available for the user to change.
There is no other way at this time to equalize within the Allstar code. You
either turn the pre/deemphasis on or off in simpleusb-tune-menu.

The in vs. out of Allstar should be flat assuming you have the emphasis set
correctly. If that is not the case then there is something wrong external
to Allstar. The Allstar codecs especially G726 and ulaw are very good
quality and probably better than any radio would be. I am not sure if that
answers your question but I am also not sure what you are trying to
accomplish.


*73 Doug*

*WA3DSP*

*http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*


On Thu, Nov 30, 2017 at 1:34 PM, "Irvin Fontanes via arm-allstar" <
arm-allstar at hamvoip.org> wrote:

> Doug,
>
> This is a private node. Just me as a user. It is used as follows:
>
> -Rpi 3 connected to an arcom rc-210 on port 2
> -icom fr-6000 on port 1 running idas 6.25 khz bw
>
> The setup is configured so that I talk into the fr6000 with an icom
> ic-f4261dt and it gets piped (in analog from the back of the db25) out to
> my other private node.
>
> I know that the audio quality takes a toll when digitized and there's
> nothing I can do about it; however; I'd like to experiment with whatever
> code/script is called out when preemphasis=yes or no and deemphasis=yes or
> no is selected since when the audio gets converted back to analog (out of
> the fr6000's db25) it is missing some of the"highs".
>
> So, could someone tell me which script is called out when preemphasis=yes
> or no and deemphasis=yes or no is selected? I would seriously like to
> experiment.
>
> Thanks,
> Irvin
>
> Irv,
>
>  Pre and de-emphasis is a fixed equalization designed around FM
> communications standards. You cannot nor should you change that. Also using
> pre or de-emphasis just to tailor audio is not a good idea. It should be
> set correctly for the radio you  are using. There is currently no
> equalization capability in Allstar within its self it is basically flat. In
> the future there may be a way to do equalization in the IOpipe channel
> driver. If you have a circuit, transceiver etc. that has poor audio
> characteristics it is best to try and fix that rather than trying to
> correct it with SW. The other issue is every radio would have different
> characteristics and if you have a node that has multiple users you would
> just be chasing your tail trying to get things right for each user or
> radio.
>
>
> *73 Doug*
>
> *WA3DSP*
>
> *http://www.crompton.com/hamradio <http://www.crompton.com/hamradio
> _______________________________________________
>
> arm-allstar mailing list
> arm-allstar at hamvoip.org
> http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
>
> Visit the BBB and RPi2/3 web page - http://hamvoip.org
>