I use 16 inch full rounds in the corners behind each speaker, and use Frescoes on the walls behind and beside the speakers for first reflection points. I also use two 18 inch X 6 foot Echobusters, and various RPG Profoam. You already know this R Suminsby, but for the rest of you, THE FIRST REFLECTION POINTS CHANGE relative to how many speakers there are. For surround sound, there are many more complex reflection points, and it can be tough to decide which ones have more effect, and which ones have less effect. I don't have a reference surround system, but if you've read ALL the literature, you know more than me already. The advantage with ASC's freestanding traps is that they can be moved around, which is perhaps what you are already doing when you go from 2 channel, to multichannel. In any case, I hope everyone else is use these essential devices.