Tus-Chan online 1,575 Posts. Joined 11/2011 Location: Mount Jitterflac What is the point of having different impedances and different gain settings at the same time? it's worked out great for me so far, since I have (for example) Grado Rs1. It is low impedance, but needs a good deal of power to sound it's best. They are there for you to set whatever setting best suits your headphone/iem.