>>I'm with you Mark. To me, the graph still has the same dips and peaks, everything has just been dampened.
I think that is what you would expect from good room treatments. You can't fundamentally change the peaks and dips except by (a) changing the dimensions of the room, (b) changing the speaker placement relative to the walls, or (c) sitting in a different place in the room relative to speakers and walls.
What bass traps can do is make the peaks smaller so you get a flatter frequency response -- when I look at that graph I see most of the peaks reduced by ~8 dB (which is a fair amount) and some reduced by 10-12 dB. I bet that room would sound MUCH better with the bass peaks taken down 8-12 dB.
Also, a frequency response graph only shows the most blatant changes. You need something with a time element, like a spectral decay graph, to show the reduction in echo at different frequencies, aka improved "tightness".
Having said that, the only "treatments" I have had time for in my new house are a borrowed rug and a pile of moving blankets in each corner (hey, I had to put them somewhere
).
