When you preview tracks in Soundtrack Pro using Match EQ in the Waveform Editor, the audio can sometimes sound distorted.
This issue occurs if you activate the Learn button (under Template) or the Learn button (under Current Material) before you load a template or audio file from which Match EQ can learn the audio spectrum.
Note: The Learn button (under Template) is red when enabled and the Learn button (under Current Material) is green when active. Both buttons are black when disabled.
The best way to avoid this is to always load a settings file or audio file from the Learn button (under Template) before attempting to preview (Control-click on the button for options). If you do get distorted audio from previewing prior to loading a template, disable the Learn button (under Template) button by clicking it once (it should turn from red to black) and the audio will play normally.