Home made absorption panels.....

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.

Tvad - Thanks for an excellent, cost effective idea.

Glitch, a couple months ago I took down my wall mounted bookcases so my friend could paint the walls for me while I was at work. I was shocked how much echo there was without them on the walls.

I did the exact thing Tvad suggested and covered the panels with a natural white needled cotton fabric at Wallmart, works good and looks good also.