Sennheiser GSX 1000 Under Linux Take Two

Fri, Dec 21, 2018

As a continuation of my previously posted Sennheiser GSX 1000 setup this is the followup which comes from a better understanding of pulseaudio and the device itself. First of all, the GSX 1000 exports three hardware devices. hw:1,0 and hw:1,1 as outputs as well as hw:1,0 as a microphone input. Regarding the outputs, hw:1,0 is actually the mono chat output that is mixed into the main 7.1 channel output by the GSX 1000. The offset from the main volume can be controlled with the small knob on the right side of the device. This makes it especially interesting for use with voice applications like mumble or teamspeak. Your friends are too loud or too low? Twist the knob and adjust on the fly. hw:1,1 is the main 7.1 channel output which - at the moment - does not get detected by pulseaudio as a 7.1 channel device which is why I wrote about the workaround in the previous post.

This new and updated solution should ease usability and possibly make this a copy and paste effort not depending on your system config. This new approach leverages udev in order to catch you plugging in your device and a special udev rule then sets an environmental variable to tell pulseaudio to use a different configuration file for the card. Also it sets a unique id so it is easier to reference the card in case you have more than one soundcard connected.

First of all you need to create a file 91-pulseaudio-gsx1000.rules in the directory /lib/udev/rules.d/ or wherever your udev stores its rules. In this file you put the following:

SUBSYSTEM!="sound", GOTO="pulseaudio_end"
ACTION!="change", GOTO="pulseaudio_end"
KERNEL!="card*", GOTO="pulseaudio_end"

ATTRS{idVendor}=="1395", ATTRS{idProduct}=="005e", ENV{PULSE_PROFILE_SET}="sennheiser-gsx-1000.conf", ATTR{id}="GSX1000"


1395 is the id for the vendor Sennheiser and 005e is the GSX 1000. After that we set the environment variable for pulseaudio and the id attribute of the soundcard. Now you need to create a second (and last, I promise!) file name sennheiser-gsx-1000.conf in your pulseaudio profile sets directory. For me this goes into /usr/share/pulseaudio/alsa-mixer/profile-sets/sennheiser-gsx-1000.conf:
auto-profiles = no

[Mapping analog-output-surround71]
description = main output
device-strings = hw:CARD=GSX1000,DEV=1
#device-strings = hw:%f,1
channel-map = front-left,front-right,rear-left,rear-right,front-center,lfe,side-left,side-right
paths-output = analog-output analog-output-lineout analog-output-speaker
priority = 2

[Mapping analog-output-chat]
description = chat output
device-strings = hw:CARD=GSX1000,DEV=0
#device-strings = hw:%f,0
channel-map = mono
paths-output = analog-output-headphones analog-output-headphones-2 analog-output-mono
priority = 1

[Mapping analog-input]
description = microphone input
device-strings = hw:CARD=GSX1000,DEV=0
#device-strings = hw:%f,0
channel-map = mono
paths-input = analog-input-front-mic analog-input-rear-mic analog-input-internal-mic analog-input-dock-mic analog-input analog-input-mic analog-input-linein analog-input-aux analog-input-video analog-input-tvtuner analog-input-fm analog-input-mic-line analog-input-headset-mic
priority = 2

# Combined output profile
[Profile output:analog-output-surround71+output:analog-output-chat+input:analog-input]
description = 7.1 Surround
output-mappings = analog-output-surround71 analog-output-chat
input-mappings = analog-input
priority = 88
skip-probe = yes

Now, all that is left is to reload udev, trigger the new ruleset and restart pulseaudio.

$> sudo udevadm control -R
$> sudo udevadm trigger
$> pulseaudio -k

After a couple of seconds pulseaudio should have restarted and you should have a nice and functional GSX 1000. Now, if someone has found a way to get software volume control working and how to keep the GSX from going Volume-Down all the time please tell me. :) Until then the temporary workaround for that problem remains unchanged and you can find it in the old article.