Magic Lantern is a custom firmware that adds a lot of functionality to Canon EOS / DSLR Cameras (7d / 5d / t2i / 60d / 600d / 550d). In this video I use the Manual Audio Function to set the internal and external mics as left and right channel, and disable the Auto Gain Control. Turning off AGC removed the hiss I was experiencing.
Vote for the left or right audio channel below!