wow huge sound system. lots of parts., did you read the manual first?
5630 is laptop M5630 is desktop. oddly.
the desktop is only 2 channel sound ,1 jack out. green.
the laptop 5630 , is 2channel also, and shows head phone ION
next to the 3.5mm jack hole.
the correct jack on a desktop is Green 3.5mm jack (line out/phones)
on a laptop they skip the rules of green and use words, or just ICON imbossed in the cheap plastic,
phones, or icon of ear phones is it, the other are mic and Line in, both useless here, ok>?
so you bought Porsche speakers for VW bug, seem so.!
to get full 5.1 sound requires a sound card or dongle with
6 outputs, 5.1 means that. 5 channel + sub woofer.
if not it will be weak sounding for sure.! for sure
what you failed to do is get a PC with 5.1 sound, or upgrade it.
here is your manual, see the red circle. that is 3 cables there.
for 5.1. front rear center and sub. if you PC is not 5.1 OPTED
the buy the USB sound dongle 5.1 and use that.
if a PC do same or buy any 5.1 sound card PCI-express
does this help?