Hi there "mr.john711". Welcome!
I'm not sure if you might have already seen it, but there's a thread here on the forum in progress right now about treating a control room.
It's on-going, part of a studio I designed for the owner a couple of years ago, so stay tuned to that for additional posts as it proceeds.
Here's a link to another room, a really high end studio, that was completed last year:
However, the techniques you see in both of those might not be applicable to your room: All rooms are different.
There's a process to setting up and treating a control room - a set of steps you can follow:
First comes layout: Orienting the room correctly, and setting out the major furniture roughly. Your room is set up backwards!
IT will never work the way you have it right now. Turn it 180° so that it is facing the 5' foot wall at the bottom of your diagram. There is no other feasible orientation in that shape space.
Next, get rid of all the clutter at the front: Anything that is not strictly involved in the actual mix process must be BEHIND you, not in front of you or to the sides. Or it can be in front of you, provided that it is below desk surface height. So in front of you, is only your desk and the speakers (and computer screen).
Now get the speakers off the desk. That's a major problem, in several ways. Having the speakers on the desk causes major comb filtering artifacts, as well as transmitting sound into the desk itself, and possibly also causing "early-early" sound to arrive at your ears before the direct sound from the speaker does (yes, it is possible). So put your speakers on stands in front of the desk. Massively heavy stands. Some people stack up bricks or concrete blocks, others use hollow steel stands filled with sand. The point is that they must be very heavy. The stands must be of the correct height: The ACOUSTIC AXIS of each speaker must end up at about 47 1/2 inches above the floor, or a bit higher (depends on speaker). That's the "standard" height for studio monitors. Note that this is the acoustic axis of the speaker that we are talking about: not the top or bottom of the cabinet, nor the middle of the tweeter, or the woofer: the actual acoustic axis. Check with the manufacturer of yours to find out where that is.
Another big problem: You have your speakers laying down on their sides! Bad idea. Flip them to stand up vertically, tweeter above woofer. That's the orientation you want, and that's where you set up your acoustic axis.
Now comes geometry: getting your speakers and mix position set up correctly. Your room is not big enough to have the speakers moved away form the wall, so the only option is to push them tight up against the front wall, except for a 4" gap which you will fill with a 4" thick panel of OC703. With 11.6' width to play with, they will have to be set up about 36" from the side walls (once again, that's the location of the acoustic axis, not the sides of the cabinet). That means they will be 66" apart. This is not 100% ideal, but it should be reasonably decent, and about the best you can hope for in that space.
Set up your chair on the room center-line such that your ears will be roughly 70" from the front wall when you are seated for mixing. Not ideal at all, but the shape and size of your room don't allow much else! Set up the desk in front of that chair position, centered side to side, in a comfortable position for mixing.
Now set up a mic stand vertically, on the room center-line, about 16" behind your chair (in other words, 86" from the front wall), and carefully rotate each speaker (without upsetting the above positioning!) such that the acoustic axis is pointing directly at that mic stand. I normally use a laser pointer for this, taped to the top of the speaker, directly above the acoustic axis, and exactly perpendicular to the front panel of the speaker. If you now sit in the chair, you will notice that the acoustic axis of each speaker is pointing roughly at your ear, or a little further outwards from your ear. It is NOT pointing at your eye, in the classic but incorrect "equilateral triangle" setup.
That's the theoretical optimum setup for your room. (Well, it's as close as you can reasonably get, given the size and shape!)
Do some critical listening tests like that, and try making very minor adjustments, to see if you can improve on the acoustic response. Try moving your chair forward and backwards a few inches in one-inch steps, rotating the speakers in each case to point at the new reference spot, 16" behind your chair. Also try moving the speakers an inch or two closer together and further apart (and rotating them to keep the aim point correct!). Don't stray too far from the initial setup, but you might find that there's a better spot with a bit of experimentation. You could even try raising the speakers by an inch or so, to see if there is less comb filtering from the desk like that, but don't go up beyond 51" (acoustic axis height, of course)
One more comment:
they will be replaced by set of Yamaha HS8's and a set of NS 10's
Forget the NS-10's The room is not big enough for two sets of speakers, and NS-10s won't be doing you any favors. And are you SURE you want to use HS8's, for Hip-Hop, R&B, and soul? At least in the first two there's substantial stuff going on down in the low end, and HS8s don't go very low... Only 47 Hz according to the manual. Not to encouraging for bass instruments... Have you considered speakers that have better low end extension? Or maybe HS8's with a sub?
OK, now that the room is set up the right way, we can get back to your original question: Treatment!
But before doing that, pull out EVERYTHING from the room except the speakers on their stands, the desk with your DAW on it, and the chair, and do a full set of REW acoustic tests with the room empty, so that you have a base-line measurement of how the room responds when empty. Here's how to do that:
http://www.johnlsayers.com/phpBB2/viewt ... =3&t=21122
With the results from that test, you can figure out what treatment you will need, and start placing it in the correct locations.
- Stuart -
Uncorrected typos: I originally thought you were referring to havnig your CR in the small booth at the bottom right, then I realized it was actually the larger room, but I had already written that part and forgot to go back and fix those. So yes, rotated 90°, and face the wall at the top of your diagram, marked 18', with the two windows in it. That has to be the front of the room.
It's your room, they are your mixes, so you can do whatever you feel like. I'm merely giving you the advice I though you were asking for, "how should I set up the room in terms o placing panels, bass traps, desk, speakers etc.": If you want to have a control room where you can track and mix optimally, then the above is how you should go about it. If you don't want that, then I probably can't help you much, because I'm not a big fan of telling people how to make there rooms sound sort of mediocre, maybe a bit OK, somewhat acceptable... I AM a big fan of helping people make their rooms great! 
