Hi there Matt, and welcome!
(I think I might have already welcomed you in another thread, but I'm not sure if that was the same "Matt"... if so, then you are doubly welcome!)
The room is almost a perfect square
Not good...
It's on a second story,
Also not good...
Current plans:
- Remove carpet, install laminate flooring
- Add super chunk bass traps (using Roxul)
- Add clouds above monitors
- Make cinder block speaker stands
Yes, Yes, Yes, and Yes! Perfect, on all counts.
You will also need treatment at your first reflection points and on the rear wall.
Room Dimensions:
L 10'1"
W 9'10"
H 7'11"
Closet Dimensions
L 2'5"
W 6'11"
H 7' 11"
Where exactly is the closet? Is it at the back of the room? In other words, does it add 2'5" of length to the room?
Should I scratch the superchunks and follow the modular design like in the drawings John provided?
For that room, I would go with superchunks. Big ones. Deep ones. In as many corners as you can hit.
2. I originally wanted to mount my speakers, but I don't know how to compensate for the increased mid range that will be an issue with the Twin 6's.
You won't have an increase in the mid range: you will have a boost in the bass. The soffit acts something like a shelving EQ at the low end, increasing the bass level by 6 dB, starting at a frequency that is given by the size of the actual speaker boxes themselves before you mount them in the soffit. This is called the "baffle step response". Basically, the soffit eliminates the need for the internal baffle step compensation that is built into the speaker, which is why most studio monitors have "room correction" or "bass roll off" or "bass tilt" controls on the rear: It turns off the circuit that was compensating for that, since you no longer need it. The issue is that a small speaker cabinet means that all of the energy in the the high frequencies radiate into half space (focused forwards), while only half of the energy in the low frequencies goes forwards: the rest "wraps around" to behind the speaker. So there is a difference of 6 dB between the high end and the low end. This is called "power imbalance" for obvious reasons, so the manufacturer artificially boosts the lows by 6 dB. But if you put the speaker in a soffit, you no longer have any power imbalance! Now ALL of the energy is going forwards. So you don't need that artificial boost any more.
I tried looking into barefoot's DIY filter, but I have no experience in soldering and wouldn't trust myself to pull it off. Is there any other options?
Your Focal 6be's have controls on the back for exactly this reason. There is a control called "Bass Contour" that allows you to cut the lows by 6 dB. That's all you need to do: turn that to -6dB, and you are done!
3. The problem areas I see are behind the door and the entire closet. I was thinking to install the large box with insulation as seen here:
That's a panel trap. It is a tuned device, set to absorb a specific frequency or range of frequencies. I don't think you'd need that. Here's what I would do:
Set up your room geometry correctly, and without any treatment at all in the room, run a test with REW. Now add the standard basic treatment devices, one by one, and do another REW test after each is in place. When you have all those in, we'll take a look at your REW data, to see what is working, what isn't, and what still needs to be be done. Then you can decide which devices you need to add, or maybe modify.
Room modes (not including closet space) for a 10'x10' room (I believe) are 56.5, 113, 169.5, 226, 282.5, 339, etc.
Not necessarily: you'd need to know the height as well, not just the length and width. Plus, your room is not 10' x 10' ...
I have the REW software and a mic to measure the room. Not sure if it's really worth to post it until I rip the carpet out.
Definitely! It wold be very interesting to see how a room changes when carpet is removed! So please do a test with the carpet still in, then another test once you have it out. Make sure the speakers and mic are in the exact same location for both of those tests, otherwise we cannot compare them validly.
Which design would work best?
Start by getting your geometry correct: First, get your speakers off that desk!!!! And get them onto stands BEHIND the desk, up against the front wall. The stands must be very solid, massive, rigid, heavy, and must place your speakers acoustic axis at 1.2m above the floor. Set the speakers so the rear edge is touching the absorption panels that you have there on the front wall, with each speaker 33" from the side wall. That means your speakers will be 52" apart. (all of this is with reference to the acoustic axis of the speaker!)
Set your chair so that your head will be 46" from the front wall. Aim the speakers so that the are both pointing at a spot about 18" behind your head.
Do your initial tests like that, take out the carpet and do another test. Then take out the treatment you already have in there, and do another test with a totally bare room. Then start putting in your new treatment, one piece at a time, with a REW test after each so you can see what it is doing.
Which design would work best?
I would go with your "green" plan for the basic treatment, but modifying it to put 6" of absorption on the rear wall, above the sofa. You could angle that: start out with 2" above the sofa, and increase it to 6" or even 8" up at the ceiling. I would also go with pure absorption on the front and side walls to start with, then only if necessary make the side ones into slot walls. With a very small room like that, I would not have tuned devices so close to your ears.
- Stuart -
(Actually, you'd be in second place, after the brand new multi-million dollar, ultra-silent anechoic facility that Microsoft just got certified....)
The math and science of Acoustics works well! 
