[LAD] Mixing audio: Implementing pan and balance

[John Rigg]

Nobody has mentioned it yet but there is a good reason why it's
useful to have pan controls on each channel of a stereo bus: it
makes it easy to check for phase errors by panning both sides
to the middle to check in mono. I do this in Ardour 2 (and on hardware
mixing consoles) all the time. The end and middle detents on A2's
panners make this quick and easy.

John