arecord -L
null
    Discard all samples (playback) or generate zero samples (capture)
front:CARD=XFi,DEV=0
    Creative X-Fi, Front/WaveIn
    Front speakers
surround40:CARD=XFi,DEV=0
    Creative X-Fi, Front/WaveIn
    4.0 Surround output to Front and Rear speakers
surround41:CARD=XFi,DEV=0
    Creative X-Fi, Front/WaveIn
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=XFi,DEV=0
    Creative X-Fi, Front/WaveIn
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=XFi,DEV=0
    Creative X-Fi, Front/WaveIn
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=XFi,DEV=0
    Creative X-Fi, Front/WaveIn
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
front:CARD=NVidia,DEV=0
    HDA NVidia, AD198x Analog
    Front speakers
surround40:CARD=NVidia,DEV=0
    HDA NVidia, AD198x Analog
    4.0 Surround output to Front and Rear speakers
surround41:CARD=NVidia,DEV=0
    HDA NVidia, AD198x Analog
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=NVidia,DEV=0
    HDA NVidia, AD198x Analog
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=NVidia,DEV=0
    HDA NVidia, AD198x Analog
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=NVidia,DEV=0
    HDA NVidia, AD198x Analog
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers