Like most houses, the room was mostly just hard (acoustically speaking) surfaces of painted wall board. The first task was to take care of first reflections. Essentially, figure out where the first sound reflection point for each speaker is (as it relates to each listener) and treat that with some absorption.
You can find these reflection points using the mirror method or by geometry (equal angles and all that) or use a CAD program. Here is one page that shows some methods. I used a free CAD program from Google called Sketch Up.
The floor was taken care of with carpet. I added three acoustic panels on the ceiling and then placed two panels directly behind the main listening area. I then added panels on the left side wall and Lisa bought and mounted a heavy duty home theater curtain which she smartly purchased at Fred Meyer.
Next was diffusion. Because the seating area is against one wall, the wall needed some diffusion to add depth, acoustically speaking. That was easy to just add a couple of bookcases. The differing dimensions of the books scatter the sound adding remarkable depth to the sound.
The net result is this:
Next post I will tell how I made the panels.
