Techniques for mixing multiple input channel signals into multiple output channel signals are provided. A graphical user interface (GUI), which includes multiple indicators, is displayed. The input channel signals are mixed to produce multiple output channel signals. The mixing is performed based on the distance between the indicators' positions in the GUI. According to one embodiment of the invention, the mixing is also performed based on the angle formed between the indicators. Thus, the extent to which an input channel signal is carried by an output channel signal is, in one embodiment of the invention, a function of both the distance between the indicators and an angle formed by the indicators in the GUI.