Processing : AudioSuite Processing : Using AudioSuite Plug-Ins : Selecting Tracks for Delay or Reverb Processing

Selecting Tracks for Delay or Reverb Processing
Because some AudioSuite effects such as delay and reverb add additional material to the end of the selected audio, it is important that you make a selection that is longer than the original source material so that the plug-in can write it to the audio file. If you select only the original material, without leaving additional space at the end, any reverb decay or delay that occurs after the end of the clip will be cut off.
To compensate for this, place the clip in a track and select the audio plus an amount of blank space at the end of the clip equal to the amount of delay or reverb decay that you have added in the plug-in. The plug-in will then have space at the end of the clip in which to write the final delay or decay. If you select more time than needed, you can trim it after applying AudioSuite processing.