[bpape]

Actually that's pretty typical and actually better than it really is because you smoothed it. Turn off the smoothing and that's what's really happening.

The material for reflection points on the side wall can be 1" or 2" rigid fiberglass or moderate density mineral wool. Normally, one would put up 2'x4' panels. Also, don't forget about corner trapping for bass frequencies. Lastly, some panels on the front wall help a lot in a multi-channel environment - not only to keep the surround reflections from coming at you from the front, but also to help smooth the bass response issues caused by the distance from speakers to the front wall.

The scale you're using is correct on the frequency axis. Try setting the level axis (vertical) to be more like 50-80db. Lastly, pretty much everything above 400Hz is meaningless in a graph like this. Set the graph to show 10-400Hz - that's where the real room issues are and we want to see as much detail as possible.

Bryan

Bran