title: sox multiple pad while mixing
body: <p>here is a solution to pad a track while mixing with another track.</p>
  
  <p><a href="https://stackoverflow.com/questions/5587135/sox-merge-two-audio-files-with-a-pad">Sox : merge two audio files with a pad</a></p>
  
  <pre><code>$ sox short.ogg -p pad 6 0 | sox - -m long.ogg output.ogg
  </code></pre>
  
  <p>How to use this command mixing multiple tracks?</p>
  
  <p>For example</p>
  
  <p>audio1.wav (no pad)
  audio2.wav (2s pad)
  audio3.wav (2s pad)
  audio4.wav (3s pad)</p>