I just got new speakers, and I can't get them to work properly. My sound card has a blue, green and pink port. The wires from my speakers are black and green. If I plug one or the other into my headphones jack either the front or back speakers will play. I can't get them both to play at the same time as the sound card seems to be doing nothing.
You need to configure your computer to enable both sound ports (front and back) if it is possible for your hardware. Sometimes it is possible to do so within the hardware page in your Control Panel in Windows (inside the sound devices page) or by entering the very driver application to your audio card.