Android class MediaPlayer's attachAuxEffect does not work
<p>I write the following code and apply them after the playback starts(mp.start()).</p>

<pre><code>  PresetReverb pr = new PresetReverb(100, 0);
  mp.attachAuxEffect(pr.getId());
  mp.setAuxEffectSendLevel((float)0.7);
</code></pre>

<p>And i could not hear any difference from when I don't apply the above code. Why? How to use this method?
I already add the permission MODIFY_AUDIO_SETTINGS by the way.</p>
