null
    Discard all samples (playback) or generate zero samples (capture)
pulse
    PulseAudio Sound Server
default
    Default ALSA Output (currently PulseAudio Sound Server)
sysdefault:CARD=ST
    Xonar ST, Multichannel
    Default Audio Device
front:CARD=ST,DEV=0
    Xonar ST, Multichannel
    Front speakers
surround21:CARD=ST,DEV=0
    Xonar ST, Multichannel
    2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=ST,DEV=0
    Xonar ST, Multichannel
    4.0 Surround output to Front and Rear speakers
surround41:CARD=ST,DEV=0
    Xonar ST, Multichannel
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=ST,DEV=0
    Xonar ST, Multichannel
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=ST,DEV=0
    Xonar ST, Multichannel
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=ST,DEV=0
    Xonar ST, Multichannel
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=ST,DEV=0
    Xonar ST, Multichannel
    IEC958 (S/PDIF) Digital Audio Output