The crossfader allows you to fade back and forth between two documents. To show or hide the crossfader control bar, select Crossfader from the View menu, or press X. The crossfader's controls include two list boxes (Source A and Source B) and a slider. The list boxes select which two documents will be crossfaded, and the slider does the crossfading. Note that the slider supports automation, which means you can program a crossfade to execute by itself, while you do other tasks. This is useful for making very slow crossfades.

When the slider is in the leftmost position, Source A is at full volume, and Source B is off. When the slider is in the rightmost position, this situation is reversed. What happens in between depends on the crossfade type, which is selected using the pushbutton located to the right of Source B. The crossfade types are explained below:

LinearOutWhen the crossfader is in the middle, each source is at half volume. Most people experience this type of crossfader as having a quiet spot, or "dip", in the middle.
DiplessInWhen the crossfader is in the middle, each source is at full volume. As the crossfader is moved away from the middle, one source is attenuated, while the other remains at full volume. This is the type of crossfader typically used in DJ mixers.

To disconnect a document from the crossfader, select a different document in the appropriate source listbox, or select "none". Be careful when doing this however. If the document was being silenced by the crossfader, it will suddenly become audible again, possibly causing a drastic volume change. To avoid this situation, set the document's volume to zero (using the Volume control bar) before disconnecting it from the crossfader. Another solution is to close the document, which safely disconnects it from the crossfader.