[arm-allstar] HAMVOIP Update 5-28-2018

[Tom Whiteside]

Thanks David - that answers my question!

73 Tom N5TW

-----Original Message-----
From: David McGough [mailto:kb4fxc at inttek.net] 
Sent: Monday, May 28, 2018 9:49 AM
To: "Tom Whiteside via arm-allstar" <arm-allstar at hamvoip.org>
Cc: Tom Whiteside <tomw at ecpi.com>
Subject: Re: [arm-allstar] HAMVOIP Update 5-28-2018


Tom,

The new low-pass filter is always enabled and assists in transcoding between
the 8KHz sample rate used by Asterisk/AllStar and the 48KHz sample rate used
by the CM1xy sound card. It is used for both 48KHz ---> 8KHz and for 8KHz
---> 48KHz.  It replaces the original FIR filter which was lower
performance.

The new DCS/PL High Pass filter is optionally enabled by setting the
parameter dcsfilter=yes in node stanza in /etc/asterisk/simpleusb.conf.  
This parameter is adjusted with option "Q" from simpleusb-tune-menu and can
be turned on/off in real-time, so you can hear what the filter is doing. For
getting rid of low-end noise, it is impressive!

73, David KB4FXC