Most cost effective room treatment?

Try the site listed below for DIY treatments that work EXTREMELY effectively. These cost pennies on the dollar compared to most commercial pieces. If your handy with some very basic tools, you can literally save hundreds upon hundreds of dollars and build pieces that are "custom" sized for your specific installation and room. If your not DIY friendly, I would highly NOT recommend the RPG ProFoam pieces. These are the biggest rip-off / highest profit margin in audio that i have EVER seen. Sean > http://members.nbci.com/Jon_Risch/

Why don't you purchase a digital Tact RCS 2.0 roomcorrection unit??? In the end you will find that this is the cheapest perfect solution...

I made 4'x 2' panels consisting of a masonite backing board, framed with 2"x 1" poplar (like a picture frame, but assembled for depth, 3" would be better). Next take some spray adhesive (3M brand works well) and some R-12 insulation. Spray the inside face of the masonite, and stick the R-12 paper side down into the frame. Now, go to "Jo-Ann" fabrics and pick your favorite cloth. They have one that looks like old KLH or Advent speaker grill cloth. Stretch this over the face of the frame and staple or nail it around the backside. Now, hold this baby up infront of your face at arms length, and yell at it. You'll here some low midrange response (bass), but absolutely no high mid, sounds like you're talking through a pillow. Make a few of these, any size you want, and hang them behind you and to the side walls to dampen high freequency reflections. They really work quite well in my listening room at home.