I have a older Cambridge Soundworks speaker system and never understood the best way to connect it to my system. The system also has the AS501 sound bar under the monitor.

The Cambridge Soundworks system is a four point surround sound system. The system has two speaker plugs, front and back.

What is the best way to connect my speakers to Dell E520 computer. I have tried different combinations and found that once I plug anything into the sourround connection (black) this disables the side (gray) and center (orange) connections. I can get sound from the gray and orange connections once the black connection is unplugged. Only one of these connections can be active.Is this typical of these three connections?

I have plugged in the AS501 into the line-in (green) and the cambridge system into the black using a reverse splitter (two female inputs to one male plug).

Thanks for any advice...

John