Dont know if you figured it out yet but it is fairly simple. Plug an interconnect to your line out of the x3ii on the other side of your head phone plug. No setting necessary. Plug other end to your C5. Line in. Plug headphone into your C5,headphone out. Power on and enjoy. i use a single band on the center part of the X3ii against the C5. It becomes a bigger brick but is a good way to have that power on the go.