I'm transferring over from Premiere Pro to Vegas Pro 8, and can't understand how to apply a real time audio edit (such as a high frequency roll off) to just one clip, or as Vegas calls them, one event.  When I selcted the one audio event and hit the FX button, up comes an effects window, but I can't hear it having any impact on the sound.  After I adjust the controls, I see no Apply button for the window, so I've just been clicking on the Close icon.  Is this correct?