title: How to set default microphone on Raspberry Pi 3B with Raspbian Stretch?
body: <p>So far I have not found any guides on how to set the default USB microphone for Stretch and so I've followed all of the guides for Wheezy and Jessie and they do not work.</p>
  
  <p>Typing in the command <code>arecord sound.wav</code> does not record anything from the microphone. However, if I were to type in this command it would work <code>arecord -f cd -D hw:1,0 -d 10 sound.wav</code>.</p>
  
  <p>Here is what appears when I enter in arecord -l</p>
  
  <pre><code>**** List of CAPTURE Hardware Devices ****
  card 1: Headset [Plantronics Headset], device 0: USB Audio [USB Audio]
    Subdevices: 1/1
    Subdevice #0: subdevice #0
  </code></pre>
  
  <p>I've edited this file /usr/share/alsa/alsa.conf and set the values to this</p>
  
  <pre><code>defaults.ctl.card 1
  defaults.pcm.card 1
  </code></pre>
  
  <p>I've also edited the /etc/asoundrc file and changed it to this:</p>
  
  <pre><code>pcm.!default {
           type asym
           playback.pcm {
                   type plug
                   slave.pcm "hw:0,0"
           }
           capture.pcm {
                   type plug
                   slave.pcm "hw:1,0"
           } 
   }
  
   ctl.!default {
          type hw
          card 0
  }
  </code></pre>
  
  <p>and this:</p>
  
  <pre><code>pcm.!default {
          type hw
          card 1
  }
  
  ctl.!default {
          type hw
          card 1
  }
  </code></pre>
  
  <p>and it still does not work.</p>