rp36.pdf
Over the course of the development of MIDI, different manufacturers have implemented their own responses to CC#10. In addition, various AMEI/MMA Specification (such as GM2 and DLS2) have recommended response curves that are not all the same. The different pan curves produce an equal power distribution between the left and right channels, but in some cases, a true center could not be achieved by following the recommended equation directly.

The formula in this RP does achieve a true center and uses an equal power distribution, which is desirable.