Pulseaudio Setup

Set audio levels with Pavucontrol

To configure the softrock server with your soundcard for IQ processing use:

pavucontrol

In order to install it, submit the following command:

sudo apt-get install pavucontrol

Choose your Soundcard for IQ processing. If you are running the SDR-Widget your settings should look like in the following two pictures.

TX audio levels on the softrock server

RX audio levels on the softrock server

Make shure not to set the RX Audio level in the Recording Tab of pavucontrol to 100%. Otherwise you could have audio feedthrough from RX to TX and a distorted TX Audio. A level from 22% - 80% would be ok, but may vary on each system.

Enable network mode

You also need to run pulse in network mode. Use:

paprefs

In order to install it, submit the following command:

sudo apt-get install paprefs

to set up network access by checking the various option boxes.

If you are using Ubuntu 11.10 there i a bug [1] that can be worked around by running this command:

sudo ln -s /usr/lib/pulse-1.0 /usr/lib/pulse-1.0.0

Pulseaudio Setup independant on a X-Server installation

Add Username to /etc/group

Make sure you add your username to the following system groups:

• pulse
• pulse-access
• audio

Use the following commands: ($USER stands for current logged in user)

sudo adduser $USER pulse
sudo adduser $USER pulse-access
sudo adduser $USER audio

Example, for the user dl6kbg the grup file must contain:

grep dl6kbg /etc/group
...
audio:x:29:pulse,dl6kbg
pulse:x:119:dl6kbg
pulse-access:x:120:dl6kbg
...

Enable Pulseaudio Daemon to run in system wide mode

sudo nano /etc/default/pulseaudio

change settings to:

PULSEAUDIO_SYSTEM_START=1
DISALLOW_MODULE_LOADING=0

Enable network mode

sudo nano /etc/pulse/system.pa

and add:

load-module module-native-protocol-tcp auth-anonymous=1

Restart pulseaudio:

sudo /etc/init.d/pulseaudio restart

or restart the system and fire up the softrock server. Pulseaudio runs now in systemwide mode and your softrock server should be able to establish a connection to your following dspserver.

Configure Pulseaudio Daemon

In order to use 96000 or 192000, you will need to configure pulse audio by editing:

/etc/pulse/daemon.conf

Uncomment these settings and change it for your needs.

Example:

default-sample-format = s24le
default-sample-rate = 192000

Tweak System for realtime performance

For realtime audio add the following to:

/etc/security/limits.conf

@audio - rtprio 99
@audio - memlock unlimited

and reboot and enjoy your system.