Bottom line regarding why they sound better where they're at is that the speakers are probably in a much better acoustical spot overall! If your speakers are coupling with the room (bass) better, and imaging better(in relation to room boundaries from where you are sitting/listening), it's because the location is better than it was, in relation!
Speaker/seating location, location, location!...nothings changed...
Speaker/seating location, location, location!...nothings changed...