Is it possible to output iscord from a dummy card?

I am trying to mix audio files with a dummy card using dmix and dsnoop:

aplay s1.wav &
aplay s2.wav &
arecord -f dat -t wav -d 3 result.wav

      

        
        
        
      

    

But is it possible?

I only have a dummy card:

modprobe snd-dummy

      

        
        
        
      

    

My ~ / .asoundrc file:

defaults.pcm.card 1 #dummy card

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

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

      

        
        
        
      

    

Performed:

CentOS6.5(x86_64)