asound.conf

   pcm.dmixed {
       ipc_key 1025
       type dmix
       slave.pcm "hw:0,0"
   }

   pcm.dsnooped {
       ipc_key 1027
       type dsnoop
       slave.pcm "hw:0,0"
   }

   pcm.asymed {
       type asym
       playback.pcm "dmixed"
       capture.pcm "dsnooped"
   }

   pcm.pasymed {
       type plug
       slave.pcm "asymed"
   }

   ctl.pasymed {
       type hw
       card 0
   }

   pcm.dsp0 {
       type plug
       slave.pcm "asymed"
   }

   ctl.mixer0 {
       type hw
       card 0
   }

ctl.equal {
        type equal;
}

pcm.plugequal {
    type equal;
        slave.pcm "plughw:0,0";
}

pcm.equal{
    type plug;
    slave.pcm plugequal;
}