pcm.!default {
    type plug
    slave.pcm mixloop
}

pcm.mixloop {
    type asym
    playback.pcm "outloop"
    capture.pcm "hw:0,0"
}

pcm.outloop {
    type multi
    slaves.a.pcm "hw:0,0"
    slaves.b.pcm "Loopback:0,0"
}