title: Sox: concatenate multiple audio files without a gap in between
body: <p>I am concatenating multiple (max 25) audio files using <a href="http://sox.sourceforge.net/" rel="noreferrer">SoX</a> with</p>
  
  <pre><code>sox first.mp3 second.mp3 third.mp3 result.mp3
  </code></pre>
  
  <p>which does what it is supposed to; concatenates given files into one file. But unfortunately there is a small time-gap between those files in result.mp3. Is there a way to remove this gap?</p>
  
  <p>I am creating first.mp3, second.mp3 and so on before concatenating them by merging multiple audios(same length/format/rate):   </p>
  
  <pre><code>sox -m drums.mp3 bass.mp3 guitar.mp3 first.mp3
  </code></pre>
  
  <p>How can I check and assure that there is no time-gap added on all those files? (merged and concatenated) </p>
  
  <p>I need to achieve a seamless playback of all the concatenated files (<em>when playing them in browser one after another it works ok</em>).</p>
  
  <p>Thank you for any help.</p>
  
  <p><strong>EDIT:</strong> </p>
  
  <p>The exact example (without real file-names) of a command I am running is now:</p>
  
  <pre><code>sox "|sox -m file1.mp3 file2.mp3 file3.mp3 file4.mp3 -p" "|sox -m file1.mp3 file6.mp3 file7.mp3 -p" "|sox -m file5.mp3 file6.mp3 file4.mp3 -p" "|sox -m file0.mp3 file2.mp3 file9.mp3 -p" "|sox -m file1.mp3 file15.mp3 file4.mp3 -p" result.mp3
  </code></pre>
  
  <p>This merges files and pipes them directly into concatenation command. The resulting mp3 (result.mp3) has an ever so slight delay between concatenated files. Any ideas really appreciated.</p>