So I connected the laptop to the Sony device via audio port from laptop and even though I select 5.1 output option in the laptop, when I test the speakers and I choose, for example, Front Left speaker, the sound comes out from all the speakers and happens the same to all 5 of them. On subuffer I get no sound at all.
Can someone give me an advice on what I do wrong?
If you are connecting your laptop with the analog/headphone output that will only do 2.0 stereo (no digital surround sound). You can try the different surround modes that your HTS has to find the one that sounds best to you with this stereo source.
If you had the option of using HDMI to the HTS then you could get digital surround sound.
The thing is my laptop has 3 jack holes and in every one of them, when I connect the HTS, I get a popup in which is asking me if I want to choose Headphones or Front Speakers. Second one it's Microphone or Rear speakers and last one is Mic In or Central/buffer speaker. So tehnicaly, when I connect the HTS and choose the option for "Front Speakers" - for example - I should get sound only for front speakers, but instead I get sound in pairs: left front + rear speaker (for testing left speaker), right front + rear (for right) and central speaker gets sounds for both left or right.
As Audio in in HTS I have 2 jacks version with Red and White, that's it