energyXT comes with built-in time-stretching and pitch-shifting, using the high-quality algorithm from http://www.zplane.de
This means you can beat- and tempo-match recorded audio tracks with the tempo of your current project.
Here's an example of an audio file playing too slow. As you can see the length of the clip doesn't match the 130 bpm.
Next, select Show object-bar from the Options menu. Or just press th 'o' key to open with shortcut.
Now, make sure your audio file is highlighted (click to select), and then select Stretch from the Resample menu.
Now that the audio file is in stretch mode, you can resize it to snap to the current tempo. Click and drag the end of the audio file to do this.
Thats it. The file now plays in perfect sync even if you change the tempo of the project.