[arm-allstar] cdm1250 transmit audio

[Doug Crompton]

Jed,

 Pre and de-emphasis are not meant to be used when they are applied to the
audio to/from the transceiver. Using them to make things sound more or less
bright when they have already been applied is not a good idea especially on
audio going out to the network. Pre-emphasis increases the high end at a
prescribed rate for audio FROM your node, what you hear. De-emphasis
decreases high end on audio TO your node, what others hear.  Most of us are
using radios that do this internally and leave these settings OFF. If you
were using a radio that did not apply one or the other or both you would
turn the appropriate one on. The bottom line is that they are not meant for
casual audio equalization but rather for a defined method every FM signal
uses.

It is in our plans and sometime in the future you will be able to apply
software equalization using an external program such as sox but for ow if
you must change equalization your best bet is feeding the analog audio out
of the FOB through a hardware equalizer.


*73 Doug*

*WA3DSP*

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


On Sun, Mar 1, 2020 at 5:00 PM "Jed Barton via ARM-allstar" <
arm-allstar at hamvoip.org> wrote:

> Hey guys,
>
> So i'm trying to do some audio adjustment on my cdm1250 to make it
> sound better.  I'm trying to figure out the pre-emphasis and
> deemphasis on the radio.  I wanna add a little more high end to the
> transmit audio.  Can i try this in simple USB, or where should i go?
>
> Cheers,
>
> Jed
> _______________________________________________
>
> ARM-allstar mailing list
> ARM-allstar at hamvoip.org
> http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
>
> Visit the BBB and RPi2/3/4 web page - http://hamvoip.org
>