pcm.!default {
    @func refer
    name { @func concat
           strings [ "pcm."
                     { @func getenv
                       vars [ ALSA_DEFAULT_PCM ]
                       default "pulse"
                     }
           ]
         }
}

ctl.!default {
    @func refer
    name { @func concat
           strings [ "ctl."
                     { @func getenv
                       vars [ ALSA_DEFAULT_CTL
                              ALSA_DEFAULT_PCM
                       ]
                       default "pulse"
                     }
           ]
         }
}

pcm.duplex {
       type asym
       playback.pcm "dmix"
       capture.pcm "pulse"
}