Constant white noise coming from speakers AND surround doesn't work correctly

[trose07]

So I got a surround sound speaker set (4 speakers, font and rear pairs, center and sub woofer) from a friend of mine. They sound fantastic, but there is always a constant white noise coming from them. It doesn't effect the audio at all but when it's quiet in the room it's loud and annoying. Also, when I try to set it up as a 5.1 surround sound setup the center and sub woofer don't make any noise when I test it (on Realtek HD audio manager and the windows sound manager thing), only the front and rear. This is my first time using a surround sound setup. Also, I have 3 audio jacks and only two plugins (3 with the mic) on the back of my computer, my friend gave me a jack spliter, But i'm not entirely sure how it works because I can only get the front speakers to work when I plug it in. Also, I don't think my PC itself is the problem because when I unplug it from my PC (So that there would be no noise at all) the white noise is still there. When I unplug the center speakers from the sub woofer the sound goes away completely even though the sound comes from all the speakers

I'm sorry for my lack of knowledge regarding this subject, I wish I could be more specific and informative. I'll try to answer and questions that I can if you need more information, but again, I don't know a lot.

 

[Suzuki@1473780084@1473780163]

Your motherboard needs to support 5.1, meaning you should see 6 3.5 jacks not 3. You want Green, Orange, Black for 5.1 to work.

 

[trose07]

Your motherboard needs to support 5.1, meaning you should see 6 3.5 jacks not 3. You want Green, Orange, Black for 5.1 to work.

Okay, I was beginning to suspect something like that after reading some stuff, so does that mean that the white noise coming from the speakers is from my motherboard not supporting 5.1 or is there another reason?