Speaker distance

Every speaker manufacturer has a different design, Driver materials, toe in and raking requirements. One must consult the designer to really understand the strengths and the negatives of the particular model of speaker. Some things are simple fundamentals for all of us at Sunny's, they are that both speakers must have the same angle in raking. this insures that both left and right speakers have the drivers firing equally if it's a one box speaker. This is a good place to start. Then one must find the rooms zone of neutrality. Mark this zone. then start working carefully documenting the progress of what you hear. This allows you to go back and verify what you heard. this allows you to grade where your speaker sounds best in the said room with the exact gear you own. Figures , charts and numbers cannot be uniform as rooms are all different, flooring materials affect speakers too. Most of all make it fun, involve a group of friends and share your passion. It's all for the music. Keep listening.

@2channel8, unfortunately it is confusing. I learned the wall you are facing, the wall behind the speakers is the FRONT wall. The rear wall is the one behind you. 

Tom

+1 @smer319 

@tomcarr, I believe that is the most common convention in manufacturers' documentation; but it surly is counter-intuitive. ;^) 

The XLO CD will get you very close. Room treatments, A mirror, laser and effort will make the final difference.