Question Need help setting up 5.1 surround system on laptop

[deadlyghost]

I have a Sony HT-RT40 5.1 surround system but it's been a pain to setup properly.
First off, there's a setting called 'Effect' which when disabled down-mixes the input to 2 channels and completely disables surround speakers. But when it is enabled, 5.1 surround works but the bass off the subwoofer is completely ripped off (i.e. no bass at all)
So far I've tried bluetooth connections but it's like I have to give up surround for bass, or bass for surround.

Here's the manual page of HT-RT40:
https://www.sony-mea.com/en/electro...und-bars-home-theater-systems/ht-rt40/manuals

Here's the specification page:
https://www.sony-mea.com/en/electro...s-home-theater-systems/ht-rt40/specifications

I use a laptop(Predator-15 G9-593) for everything and it's hooked up, via HDMI, to a monitor(Acer Nitro VG270P) that has 2 HDMI ports(non ARC) and 1 DisplayPort. The surround system has only HDMI out for ARC but that doesn't solve anything since I don't have a TV. Also, there's optical cable and analog 3.5mm for inputs. Since I'm aiming for 5.1, that rules out 3.5mm. But is it at all possible to get optical cable connected to my laptop through some external sound card or something?
I have an old ASUS Xonar that has optical out but I don't know how that would connect to my laptop cos I couldn't find PCIe to USB convertors.

I really don't want to give up on bass just to have the damn surround working.
Any suggestions are appreciated!

 

[popatim]

USB DAC?