Room acoustics

How about a thread on room acoustics and ways to improve the in-room performance of your system and its speakers? Subjects covered could be the physics of room response, measurement of response in your own room, and how to deal with imperfections, above and below the Schroeder frequency, like damping, bass traps, speaker positioning, (multiple) subwoofers, and dsp equalization. Other subjects could be how to create a room with lower background noise for greater dynamic range, building construction, or what to do in small rooms.
I am a bit busy just now, but as soon as I have time I will try to kick off with some posts and links.
@toddverrone much better, now you can see more of what's going on. Here are a few targets for you to hit with your tuning from the excellent Acoustic Frounteers guide.

Resonances from 35Hz­300Hz should not extend beyond 350ms before decaying into the noise floor or reaching a level of ­40dB.

Below 35Hz this standard is relaxed to 450ms.

Try to plot RT60 time for various frequencies.

In the bass you should aim for less than 1 and around 0.4 over the rest. Also adjacent RT60 times should be similar - so your reverberation needs to be even to sound right and natural. A larger space can handle more reverb. A small space needs more treatment. There are rules of thumb for RT60 depending on genre and venue space.

See this system thread

See how I presenrt the 3D waterfall plot in a meanngful way. Your plot is diffcult to interprete.

I'm not sure why mine is difficult to interpret and yours is easier.. I'm new to all this. I just really learned last month what a waterfall plot shows and am just now figuring out how to read it with regards to looking for problems. 

I'll try to make sense of what you just said.. I know rt60 is classified as a measure of clarity in REW, other than that, I'm in the dark. I have lots of reading to do it seems.. I'm certainly not expecting any of you to explain it to me, so I appreciate all comments. The give me things to learn and figure out.