mixxx2

   pcm.!default {
        type plug
        slave.pcm "mixxx"
    }


    pcm.mixxx  {
        type dmix
        ipc_key 1024
        slave {
            pcm "hw:0,0"
            period_time 0
            period_size 1024
            buffer_size 4096
            rate 44100
            channels 7
        }
        bindings {
            0 0
            1 1
        }
    }

    ctl.mixxx {
        type hw
        card 0
    }