Digital Panning Effect
To get a panning effect I know that there is a need for a Circular Matrix. The angle is can be set as a default or I can let the user to select the angle.


How do you know this? Can you cite a source? Audio Panning is typically done with one input and two outputs. It's either done with constant energy or constant amplitude pan. Constant energy is similar to what the second column of your matrix would do if the angle goes from 0 to 90 degree with 45 degrees being "centered"