The 13's seem to transcend the typical definition of in or out of head, stage.
I have been trying to figure it out. It is like you are transported. You do have the stage in your head, yet there are sound to the far right and left and deep. It is your head but not. It is, for me, very difficult to explain. The stage, world that exists, is now what you hear and it doesn't really matter if it is a head stage, it can not be defined by that, it is a stage, and it is music.