They seem best to me with a few feet of room
(Grabbing the tape measure now…)
It says 45” behind and 55” to the front.
But I sort of moved them around quickly and thought, that seems OK few months ago… So it was not exact by any stretch.
Firstly; I know that the Mrs says that they are always too far out into they room.
Secondly; she often says that the sound is coming from behind the front wall.
And thirdly; that the speakers make no sound, and that all the sound it is coming from between the speakers.
She is an intelligent woman, but the phantom image is outside of her bailiwick of understanding.
…in an 18’ 5" long room. I could stretch that to 13" which is 1/17 the room length…
1/7th of 14 feet is about 2 feet and 1/7th of 21 feet is ~3 foot.
So 1/7th of 18’ should be about 2-1/2 feet I think?
(That is about the minimum IME.)