Something

pcm.!default {
    type plug
    slave.pcm "dmix"

pcm.dmix {
    type dmix
    ipc_key 1024
    slave {
    pcm "hw:0,0"
        period_time 0
        period_size 1024
        buffer_size 4096
        rate 44100
        format S32_LE
    }
    bindings {
        0 0
        1 1
    }
}