Problem with surround sound

[Calky]

I have the Logitech z-640 surround sound speakers and I get no sound out of the back two speakers, but the 2 front ones, central and sub woofer works fine. And when I connect it to my television for my xbox 360 it works fine only when connected to the computer it doesn't work. (in advanced audio properties I have it set to 5.1 surround sound speakers) can anyone help me. Oh and I have creative sound blaster live! 24-bit sound card.

 

[Rage_3K_Moiz]

Have u inserted the cables properly to the sound card? Are they in the appropriate inputs? Ur sound card should have a black-coloured input for the rear speakers.

 

[Calky]

The speakers have thee cables green, orange and black and they are all correctly inserted to the sound card, the sound card also has a blue input and I'm not sure what this is for. Anymore suggestions.

 

[Rage_3K_Moiz]

I guess then the sound-card is faulty then. Can u test the speakers in another PC to see if they're working?

 

[Calky]

I have another pc at home but it doesn't have a sound card that supports surround sound.

 

[Calky]

When you stick the black cable into the input the speakers do make a buzzing noise like it does with the other cables.

And I have another pc at home but it doesn't have a sound card that supports surround sound.