So, I did a little more research and I am pretty convinced about buying a relatively simple entry level audio interface, I guess it will serve all my purposes and still give me a decent sound quality and with balanced outputs.
I was thinking about buying behringer UMC204HD, and then connect it through USB to my notebook, and then make the connections like this:
interface left TRS out ---> sub left TRS in
+
interface right TRS out ---> sub right TRS in
///
sub left XLR out ---> monitor left XLR in
+
sub right XLR out ---> monitor right XLR in
It would look like this illustration from JBL's manual, but with the interface instead of the mixer, and the interface connected to the PC:
What do you guys think about it??
Thank you all for the help and tips, appreciate it!