Equal power panning balances two channels. By panning from left (pos=-1) to right (pos=1) you are decrementing the level of the left channel from 1 to 0 taking the square root of the linear scaling factor, while at the same time incrementing the level of the right channel from 0 to 1 using the same curve. In the center position (pos=0) this results in a level for both channels of 0.5.sqrt (~=0.707 or -3dB). The output of Balance2 remains a stereo signal.
channel 1 of input stereo signal
channel 2 of input stereo signal
pan position, -1 is left, +1 is right
a control rate level input.