Acoustic panels

I'd suggest reading "Sound Studio Construction on a Budget" by F. Alton Everest. He covers domestic listening rooms too and this book came 10 years after his "Master Handbook of Acoustics", and has info on newer products--RPG, especially. You can learn all kinds of things about room acoustics from this book, and where to locate your four absorptive panels in particular. You'll probably want to do other things too.

i'm sure you'll wanna read something on the subject but i'd say, generally, (if your sound panel design works-i have doubts) you'll do best starting directly behind your speakers, assuming you've already removed EVERTHING from between your transducers. go toward the side walls as far as possible, covering the area in the very center first..

You want to treat all first refelction points. Usually, this will mean 2 panels on each side wall, two panels on the ceiling and, depending on hwere speakers ar eplaced, 2-3 panels on wall behind the speakers. For the final touch, one panel to diffuse sound behind the listening position. If you only have 4 panels, suggest you treat the side walls. To gifure out where to place them, have a friend move a mirror along the wall while you seat on the sweet spot. You want to treat the spot on the wall where you see the tweeter from each loudspeaker reflected. If the panels are large and the speakers close to one another, one panel may do the trick. If you must know more, the book by F. A. Everest is a good place to go. R. Harley also deals with this in his book.