I would think that different speakers would make for different positioning. Due to the constraints of my living room, my speakers are along the long wall about 7'10" (center to center) apart and I sit a about 7' back and I get excellent sound. Even my speaker maker, who at first thought they were too far apart, thought the soundstage was great the way it was, after he heard it.
All of those formulae are great for starting points but there are too many variables to be absolute. Those kids are onto something. Trust their ears.
All of those formulae are great for starting points but there are too many variables to be absolute. Those kids are onto something. Trust their ears.