Here are pictures of my proposed placement of my 9 existing acoustic panels.
Front of the room with proposed placement of acoustic panels, the outer two have 6 inches of fiberglass and the middle one is 4" thick. I think I may remove the existing shelves so the panels will fit in a single line and so I can get the speakers as wide as possible, since I am giving up at least a foot and a half of separation between left and right compared to my prior setup.
Right wall. Two 2" thick panels with a 2 inch air gap behind them. These will be wrapped in white fabric for better appearance. The boxes in front are my 2010 JTR Triple 8's. After carrying them down the stairs, I am happy that I didn't buy Triple 12's a couple of year ago. However, I am worried about trying to get the 190 lb Captivator S2 down the stairs without hurting it or the wood of the stairs.
Four acoustic panels with 4" of fiberglass with a 2 inch air gap. These will cover the window. The middle two are homemade and will be covered in white fabric for better appearance.
Do you guys have any suggestions for placement of my panels? Is this a reasonable use of what I have? All of the panels will, of course, be hung higher on the wall, placement on the floor is just for planning purposes.
Acoustically, what is the best thing to fill the built in bookshelves on the left of the room with? Are books any good at absorbing or diffusing?