Above are screenshots from a Measurement I took of my control room. I can't tell if I just don't know how to take measurements or if I just need help interpreting those measurements as reflected in particular in some waterfall graphs. The graphs above include one SPL measurement for context and then two sets of waterfall graphs (each set contains one screen shot of graph and then screen shot of graph showing the settings used for that graph). One screen shot is for the frequency range: 15hz-400hz and the other is 15hz-22,000khz.
Below is a description of how I configured REW, how I took the measurements and what my Control Room is like. I would like help understanding the waterfall graphs above so that I can determine whether my room needs more treatment, is as good as I can get it, or needs less treatment; and, depending on the answer, whether EQ would be appropriate at this time before getting on with mixing and mastering somewhat soft, though occasionally hard, pop/rock.
Firstly, my control room is roughly 15' x 12'. I am oriented parallel with the 12' walls; perpendicular to the 15' walls. I sit basically in the center of the room facing a wall that is mainly windows which are completely covered with several sound absorption blankets. I am a little off center about 20 closer to the wall to my left. My speakers are obviously closer to the wall I am facing. The speakers are roughly 3-5 feet from the back wall and I have two sets of near-field speakers. One set, NS-10s (Frequency range: 90hz-18,000khz) make a a 10 foot -sided triangle with me in my listening position, while my other set of near-field speakers sit inside of the NS-10s. They are JBL 4410s (Freq. Range - 30hz-20,000khz) and they make a 6'-sided triangle with me at one end. There is no subwoofer and I took my measurements with the correct setting, accordingly.
Where I sit is basically in the center of the room towards a wall which is made up mostly of windows that are covered with two large sound absorption blankets. I am a bit off-center from the walls to my sides - so that I am roughly two feet closer to the wall to my right. That wall is actually a slightly slanted wall, so the room is not a true rectangle. That wall meets the corner of the wall I am facing at about s 10-15 degree, so at that end of the room the angled wall is about 12' from the opposite wall. If you follow the wall to the other end, it is about 14' from the opposite wall where it meets the back wall behind me (if you can picture this; it's hard to describe, but too difficult to capture in a photo).
As to room treatment, the 12' wide wall I am facing, as I said, is made up mostly of windows and they are covered with sound absorption blankets. The side walls and areas of the ceiling are treated with quite a bit of Auralex 2" squares in shapes; some on the ceiling right above the speakers, some right above my head where I sit. Three of the four corners have two 4'x2' 4" thick bass traps which go from floor to ceiling (they are at an angle so the sides touch the walls and each side is at roughly a 90 degree angle to the wall? I made these traps using 4" corning fiberglass with the aluminum facing into the room and covered with a burlap-like fabric (I don't remember the exact type of fiberglass, but it is the one recommended on most DIY bass trap sites). I should also mention that I have set up against the back wall several different pieces of furniture, a large bookcase filled with books at the center of the wall and a small chest of wicker drawers next to it. There is one corner of the room I could not put bass traps, or really even treat because there is a door 1 foot from the corner against the two adjacent walls.
I took the measurement from which the above screen shots of the graph I generated using a Cross-Spectrum calibrated EMM-6 and the the calibration file loaded with a 90 degree narrow band file, with the microphone facing the ceiling. My soundcard, Lynx L22, cal file was also loaded and I calibrated the SPL with an analog Radio Shack SP meter set to 80 "C" and "Slow." When calibrating, I entered, I believe about 156 dbs to calibrate.
When taking the measurement, the microphone was facing the ceiling roughly where my right ear is in listening position with both JBL 4410 speakers playing the output of the right channel from my soundcard. The preamp showed the level of the speakers was just below 0 dbs. The measurement was a 512k, 11.9s, single sweep from 15hz to 22,000khz.
As you can see I have one screen shot showing the SPL from 15hz to 22,000khz for reference and then two pairs of waterfall screen shots (each pair shows one of the waterfall, and then the same waterfall with the "Limits" and "Control" box on the screen for reference. The first and more important waterfall is from 15hz to 400hz with 5db increments on the y-axis, the second is from 15hz to 22,000khz with, if I remember 10db increments on the y-axis.
One thing that confuses me is that with all my measurements, my SPL and the top of my waterfall graph shows up at about 160 dbs. Is that correct. Also, with the waterfall graph, there is no way to show both the top of the graph and the sound floor in 5 db increments, but I can see them at 10db increments because the top is around 160dbs, while the sound floor starts to appear between 45db and 65db. Also, the reading on the 15hz-400hz waterfall that concerns me is that from 15hz to I believe 60hz, or 90hz (see photo, I can't remember) the sound at that end is still going strong whether I select 400ms as in the graphs you see, or even if I select 1000ms. I know the JBLs don't really start to put out much sound until they really hit 40hz, so why is there so much sound below 40hz?
Can you tell from what you see and what I've said whether I'm taking measurements properly? If I am, can you tell me what I should deduce from the waterfall graph? Can I learn anything from the SPL graph. What other graphs should I generate based on what you see to help me focus on whatever problems you see?
Any help would be greatly appreciated as I am new to this and I have spent countless hours reading through Theater Shack forum threads, the REW manual, RealTraps Info, and anything else I could learn about the subject.
Thank you if you even read through this let alone provided any response or guidance. Thank you again!