I'd need help to configure Terratec Aureon 5.1 MK2 USB card to downmix 5.1 to 4.0. I have tried this time to time on linux but never got it working. All the other variations shows up correctly (4.1, 5.0 and 5.1) but 4.0 is not even listed e.g. on pavucontrol GUI. I have created a new udev rule to ensure the same configuration is always used. Udev calls profile "terratec-aureon-51.conf". Currently there exists only two mappings: 4.0 and 4.1. And only 4.1 shows up correctly.. ---clip--- udevadm info -qall -p /sys/class/sound/card1 P: /devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2:1.0/sound/card1 E: DEVPATH=/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2:1.0/sound/card1 E: ID_BUS=usb E: ID_FOR_SEAT=sound-pci-0000_00_1d_1-usb-0_2_1_0 E: ID_ID=usb-0ccd_USB_Audio-00-Aureon51MkII E: ID_MODEL=USB_Audio E: ID_MODEL_ENC=USB\x20Audio E: ID_MODEL_FROM_DATABASE=Aureon 5.1 MkII E: ID_MODEL_ID=0028 E: ID_PATH=pci-0000:00:1d.1-usb-0:2:1.0 E: ID_PATH_TAG=pci-0000_00_1d_1-usb-0_2_1_0 E: ID_PRODUCT_FROM_DATABASE=Aureon 5.1 MkII E: ID_REVISION=0100 E: ID_SERIAL=0ccd_USB_Audio E: ID_TYPE=audio E: ID_USB_DRIVER=snd-usb-audio E: ID_USB_INTERFACES=:010100:010200:030000: E: ID_USB_INTERFACE_NUM=00 E: ID_VENDOR=0ccd E: ID_VENDOR_ENC=0ccd E: ID_VENDOR_FROM_DATABASE=TerraTec Electronic GmbH E: ID_VENDOR_ID=0ccd E: PULSE_PROFILE_SET=terratec-aureon-51.conf E: SOUND_INITIALIZED=1 E: SUBSYSTEM=sound E: SYSTEMD_WANTS=sound.target E: TAGS=:seat:systemd: E: USEC_INITIALIZED=28795964 ---clip--- aplay -L null Discard all samples (playback) or generate zero samples (capture) pulse PulseAudio Sound Server default Default ALSA Output (currently PulseAudio Sound Server) sysdefault:CARD=ICH6 Intel ICH6, Intel ICH6 Default Audio Device front:CARD=ICH6,DEV=0 Intel ICH6, Intel ICH6 Front speakers surround40:CARD=ICH6,DEV=0 Intel ICH6, Intel ICH6 4.0 Surround output to Front and Rear speakers surround41:CARD=ICH6,DEV=0 Intel ICH6, Intel ICH6 4.1 Surround output to Front, Rear and Subwoofer speakers surround50:CARD=ICH6,DEV=0 Intel ICH6, Intel ICH6 5.0 Surround output to Front, Center and Rear speakers surround51:CARD=ICH6,DEV=0 Intel ICH6, Intel ICH6 5.1 Surround output to Front, Center, Rear and Subwoofer speakers iec958:CARD=ICH6,DEV=0 Intel ICH6, Intel ICH6 - IEC958 IEC958 (S/PDIF) Digital Audio Output sysdefault:CARD=Aureon51MkII Aureon5.1MkII, USB Audio Default Audio Device front:CARD=Aureon51MkII,DEV=0 Aureon5.1MkII, USB Audio Front speakers surround40:CARD=Aureon51MkII,DEV=0 Aureon5.1MkII, USB Audio 4.0 Surround output to Front and Rear speakers surround41:CARD=Aureon51MkII,DEV=0 Aureon5.1MkII, USB Audio 4.1 Surround output to Front, Rear and Subwoofer speakers surround50:CARD=Aureon51MkII,DEV=0 Aureon5.1MkII, USB Audio 5.0 Surround output to Front, Center and Rear speakers surround51:CARD=Aureon51MkII,DEV=0 Aureon5.1MkII, USB Audio 5.1 Surround output to Front, Center, Rear and Subwoofer speakers surround71:CARD=Aureon51MkII,DEV=0 Aureon5.1MkII, USB Audio 7.1 Surround output to Front, Center, Side, Rear and Woofer speakers iec958:CARD=Aureon51MkII,DEV=0 Aureon5.1MkII, USB Audio IEC958 (S/PDIF) Digital Audio Output ---clip--- cat /usr/share/pulseaudio/alsa-mixer/profile-sets/terratec-aureon-51.conf [General] auto-profiles = yes [Mapping analog-surround-40] device-strings = surround40:%f channel-map = front-left,front-right,rear-left,rear-right paths-output = analog-output analog-output-speaker analog-output-desktop-speaker analog-output-lfe-on-mono priority = 6 direction = output [Mapping analog-surround-41] device-strings = surround41:%f channel-map = front-left,front-right,rear-left,rear-right,lfe paths-output = analog-output analog-output-speaker analog-output-desktop-speaker analog-output-lfe-on-mono priority = 7 direction = output ---clip--- BR, -- Wille OH5LEP