I have a large wooden hutch between my speakers about a foot back. I do notice a difference when I place a thick blanket on it- really clears things up and provides a darker background for the sound (it's not so bright I find). The other day I took my DIY first reflection panels and put them in front of the cabinet- I found that there was more detail but I lost the breadth of the soundstage (by loosing the 1st reflection absorption). It was enough that I will make a set of panels for them later.
so I agree with Ethan (not that I would ever disagree with him

).... try a heavy, thick blanket and if it makes a difference then get some absorption panels.
and then let us know what you think
jim