Z-906 3d surround sound messing with music on computer

[Sensuibe]

Hey guys,
Long time lurker here at tom's hardware, but first post. Hope i'm in the right area.

So i just went out and treated myself to the Lgitech z-906 5.1 surround system, and since i didn't feel speakers of this caliber should be used with my motherboard's integrated sound card, i picked up the creative x-fi fatal1ty sound card.

Installed everything but for some reason when i have it in 3d surround sound mode some of my song's vocals and sometimes instruments are VERYY quiet. When i use the control console to change the stereo mode to default (5.1) it sounds perfectly fine, I'd really like to get 3d surround working as the songs sound much better aside from the quiet vocals.
is this normal? suggestions?
I'm using 3.5mm to connect pc to subwoofer.

Let me know what you think and thanks in advance!

Sensui

 

[soundguruman]

Well if you have the music playing in surround sound, all the speakers have to be connected, and the volume of each speaker has to be adjusted with the audio controls.
The quiet vocals are the result of no center channel speaker?