[App_rpt] irlp audio vs asterisk audio (channel drivers)

Ramesh Dhami (VA3UV) Ramesh at va3uv.com
Thu Oct 30 15:31:50 EDT 2008


James Nessen wrote:
> I recently setup a node for a buddy of mine and we moved him to the 
> channelized irlp and echolink installation.  He has recently received 
> poor audio reports from the IRLP side of his node and we did a A/B test 
> one night on his audio.
> 
>  
> 
> I found that his Asterisk audio is great, and is full of audio (our two 
> nodes connected via uLaw).  leaving the volume on my HT, I disconnect 
> from him via AllStar and then connect up to him via IRLP.  His audio on 
> the IRLP side is about 10% lower than his level when were chatting via 
> AllStar and also sounds muffled.  Has anyone else noticed this?  If so, 
> is there a fix for it?
> 
>  
<-- Hi Jim;  I have also noticed this on my chan_irlp node (2304).  I 
believe part (if not all) of the issue is due to the fact that app_rpt 
and irlp use different audio levels as the calibration standard (3.2kHz 
and 3.5kHz deviation respectively).  Of course then there is the ADPCM 
to ulaw conversion...

I have previously discussed this with Jim (WB6NIL); I know that he'll 
come up with a fix!

HTH,

Ramesh.

app_rpt node 2182



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