My current understanding is that you will *never* get the same soundstage when listening to speakers verses listening via headphones for one simple reason; with speakers your ears hear both sound sources (left and right) but with a delay from the opposite channel which helps position things. But with headphones your ears only hear one source - left or right channel per ear. That creates a totally different soundstage interpretation by your ears/brain. So I think that the soundstage (from the same recording) as a minimum will always be wider (pulled to the sides away from center) when using headphones due to the lack of time delay which one would heard from the other channel if listening to speakers which would move images potentially more into the center of the soundstage. At least that's my current understanding.