Room Acoustics: Where to place the squares?

I got some sound squares. Where do they go? Behind the speakers? Ceilings?

Back walls?


No more info than you're giving might as well place the squares in the closet. 

@magister and @erik_squires

That site talks about room modes.
Are you two fellows also discussing room modes?

And what is OP looking for? Room modes?

 For a while, I worked for the local college repairing some of their abused machinery. Usually the ticket would read "broke" or "doesn't work". What we have here is a lack of communication. One of my favorite movie lines.