Surround : Surround Panning and Mixing : Divergence and Center Percentage : Divergence Editing Mode

Divergence Editing Mode
In Divergence Editing mode, you can adjust the divergence boundaries by dragging directly in the Divergence Grid.
To adjust divergence graphically:
1 Click on the Panning Mode button until the Divergence Editing icon is displayed.
 
2 Drag in the Grid to resize the divergence boundaries.