So to start off i have a Asus ROG strix z-390 e - gaming motherboard and i have a monoprice ssw-12 12" sub and my normal speakers are logitech z313 speaker/bass pair. So my main problem is that i cant get them to work at the same time. I dont know if i even can but i dont know how to go about trying to get them to work at the same time. I have the sub plugged into the c/sub port and the speakers into the green line out port. If someone has any idea how to get them to work it would be much appreciated!
You need to change your audio to 2.1 in the audio control panel of the PC.
Then connect the sub to the c/sub jack using a cable with a stereo mini plug at the PC end and two RCA plugs at the sub end. You will only use one of the RCA plugs (only one has bass) and you can plug it into either RCA input.
If the subwoofer has RCA inputs and outputs then you could connect the green audio output to both RCA inputs and connect the output to the input of the Z313 system.
Using the sat/sub + sub will work better the first way of connecting it since it will minimize the interaction of the two subwoofers.
The other method has both subwoofers working over the same range of sound and may not work as well.