Home made absorption panels.....

One problem that I have is that one ref. point will be on a sliding glass door covered with vertical venetion blinds. Maybe I can build something on a floor stand. Any ideas?

oops, I responded too early to these useful suggestions in my previous post. They`ve all been useful and will be concidered. Thanks for your input.

Tvad's suggestion is a good one, because you can tailor the look of the panels to your aesthetics and room decor.

Does the bookcase filled with books thing really work? If so, would it be better than, say Tvad's homemade panels? I have two bookcases full of books that I could use for this purpose but before I was thinking of draping a cloth over them so they'd be less distracting.