Sound Issue

Ok so ive got an m17x R2 and ive got 5.1 logitech speakers. All the cords and everything from the speakers lead back to the sub which is plugged in. there is a Main speaker which is the front right speakers, this one has three cables coming out of it which connect to the computer, green, black, and orange. Now for some This m17x didnt color code the jacks on the computer, they are all black. The two leftmost are labeled with a headphone symbol the next one to the right has like a circle thing with an arrow through it. So basically do i have it hooked up right, ive got green on the far left, then black, then orange.
Next question, what the hell does the orange one do? i unplug it and plug it in and the volume changes slightly, but thats all i can notice(im sure its doing more but what?), and my center speaker Never seems to do anything.

The reason im asking about all this is i was playing SC2 and for some reason i could not hear one of the characters. Specifically the A.I computer lady who tells me what challenges i am about to undertake. Now when i changed the audio settings to R.T.C everything worked fine. Then i went onto the internet and tried to listen to a song and had no sound. Why do i have two options for sound when they are plugged into the same place? how can i make sure i am getting 5.1? I need the game to work(which it does over the R.T.C thing but is that 5.1?) and i need everything else to work without changing settings or unplugging anything. Thanks for the help sorry for being disorganized.

 

OK so i downloaded a little test file and No matter what i only hear front left, and front right, when i should be hearing front left, center, front right, rear right, rear left, and then sub.

 

Not sure if you tried changing things in control panel > IDT Audio Control > Under Setup (left column) > Speaker Setup - You can change the system to 5.1 if it's on stereo (default on mine).
Then you also have to setup the audioplugs on the right side and set them to the corresponding jack.

Just a thought reading from this topic:
http://forum.notebookreview.com/alienware-m17x/418509-m17x-5-1-external-speaker-input.html

Sorry if i can't test it for real, can only play with the options in IDT Control, as i don't have any 5.1 system, but i would be curious if you even knew about that or where did you set R.T.C. (which stands for Real Time Communication and is normally used for headsets)?

Should look something like this, with all speakers showing up(if they don't check the output options on the right and make sure it's set to speakers and not headphone:

 

got it worked out, was a combination of all kinds of things, basically tho disabled the rtc thing reconfigured and switched around some cables while testing with the sound file. Either way it works now.