title: Playing sound in Matlab at +30dB
body: <p>As far as I know when I load wav files to matlab with command:</p>
  
  <p><code>song = wavread('file.wav');</code></p>
  
  <p>array song have elements with values from -1 to 1. This file (and hardware) is prepared to be played with 80dB. I need to add +30dB to achieve 110dB.
  I do +10dB by multiplying by sqrt(10), so to get +30dB I do:</p>
  
  <p><code>song = song*10*sqrt(10);</code> which is the same as</p>
  
  <p><code>song = song*sqrt(10)*sqrt(10)*sqrt(10);</code></p>
  
  <p>Now values of array song have much greater values than -1 to 1 and I hear distorted sound.
  Is it because of this values greater than &lt;-1,1> or quality of my speakers/headphones?</p>