Fixing EVO4 surround issues on Bazzite
After moving to Bazzite my Audient EVO4 showed up as Analog Surround 4.0 despite being only stereo. In games that meant that I wouldn’t hear anything behind me, which was highly annoying.
The fix is a custom ALSA Card Profile that remaps all four channels to the two real outputs. As a disclaimer: this solution was created by Claude, but it works on my machine ;)
1. Create the profile
sudo mkdir -p /etc/alsa-card-profile/profile-sets
Create /etc/alsa-card-profile/profile-sets/audient-evo4.conf:
[General]
auto-profiles = yes
[Mapping mic-input]
description = Mic
device-strings = hw:%f
channel-map = mono,mono,aux1,aux1
paths-input = analog-input-mic
direction = input
priority = 1
[Mapping multichannel-input]
description = Multichannel
device-strings = hw:%f
channel-map = front-left,front-right,front-center,lfe
paths-input = multichannel-input
direction = input
priority = 2
[Mapping analog-surround-40]
description = Analog Surround 4.0
device-strings = front:%f
channel-map = front-left,front-right,front-left,front-right
paths-output = analog-output
direction = output
priority = 1
[Profile output:analog-surround-40+input:mic-input]
description = Analog Surround 4.0 Output + Mic Input
output-mappings = analog-surround-40
input-mappings = mic-input
priority = 100
skip-probe = yes
[Profile output:analog-surround-40+input:multichannel-input]
description = Analog Surround 4.0 Output + Multichannel Input
output-mappings = analog-surround-40
input-mappings = multichannel-input
priority = 60
skip-probe = yes
The key line is channel-map = front-left,front-right,front-left,front-right — it folds all four channels into stereo.
2. Create a udev rule
Create /etc/udev/rules.d/91-audient-evo4-acp.rules:
SUBSYSTEM=="sound", SUBSYSTEMS=="usb", ACTION=="change", KERNEL=="card*",
ENV{ID_VENDOR}=="Audient", ENV{ID_MODEL}=="EVO4",
ENV{ACP_PROFILE_SET}="audient-evo4.conf"
3. Reload
sudo udevadm control --reload
sudo udevadm trigger --subsystem-match=sound
systemctl --user restart pipewire pipewire-pulse wireplumber
Log out and back in if needed.
Test it
pw-play /usr/share/sounds/alsa/Front_Center.wav --target "alsa_output.usb-Audient_EVO4-00.analog-surround-40"
Centre audio should now come through your headphones. Set games to Stereo or Headphones — the EVO4 isn't a surround device.
Note: the udev vendor/model values and the pw-play target name are specific to my system. Yours may differ — run udevadm info /dev/snd/controlC* to check.
Reverting
Delete the two files and restart PipeWire:
/etc/alsa-card-profile/profile-sets/audient-evo4.conf
/etc/udev/rules.d/91-audient-evo4-acp.rules