The Channel Mixer will enable you to create new stereo mixes using the existing right and left channels as input sources. With different combinations, you can create some interesting stereo imagining effects like: Average, Invert, Swap Channels, Wide Stereo, Vocal Cut...
Gives you a good amount of control over left and right channels, useful for different stereo effects. Includes a few presets such as stereo swap, vocal cut, invert, etc.