B&W 800D2 versus 802D2

I've changed my B&W 802 D2 for a B&W 800 D2 two months ago, let it playing continuosly to pass through the burn-in period (like I did with the 802 D2). My electronics, cables, listening room and speaker position are exactly the same. They are approximately 0.5 meters from the walls and around 3 meters apart each other, and 3 meters aways from the listening position (sopha). I just changed the speakers, nothing else. Bass is much better with the 800 D2, but midrange and high frequencies were better with the 802 D2. They were cleaner and softer. However, when I listen to the 800 D2 standing up, the midrange and treble get much better than when I'm seated, a similar sound quality than the 802 D2 (seated). So, what should I do to get a 800 D2 mid and treble quality similar to the 802 D2? Any thoughts?