Taller than 4'. I just don't know if the curtain rod is solid enough to support hanging the panels, but I like that idea as it would be quick and simple.
Thanks for the offer on the road trip and I certainly would like to take you up on that offer sometime. Actually, I just did a little trip out to Oregon to visit with my buddy mchuckp and his room was what got me thinking about more room treatments again. Just sounded fantastic. He's got quite a bit of open space behind the LP and the rear wall is treated with 2 244 panels. Made me think I should attempt to do something similar if I could.