How to mute ground noise/hissing?

[AwArEnEsS]

I am connecting my Pc to powered speakers using a 3.5mm to 2 rca + Y splitters. I notice some hissing noise which I expected. While I am listening to music or playing video, it's mostly not noticable.

While I am playing older games, not a problem but if I start playing a resource-hungry game, psu draws more power and the noise starts to irritate.

Should I buy a Dac, a ground isolator or a ci box to eliminate hissing completely? Which would be less expensive but still make the job done?

There are a few other things to consider. I want to be able to connect my powered speakers to Tv via tv's optical output and speakers' rca output. I bought a dac for it but it seems corrupt.

Also I want to be able to connect my powered subwoofer to Pc and if possible to Tv too, should I buy a multi channel (5.1) dac for it? If I just buy a stereo Dac, connect my speakers to it and then connect my subwoofer's rca line-ins to powered speaker's Xlr output using a Xlr to rca +Y spitter, will my subwoofer work?(without having to buy a 5.1channel dac)

So I want to be able to do all of the things which I mentioned, if possible I just want to buy just one device and accomplish all of these. What should I buy, which type of device?

[theSven]

I am connecting my Pc to powered speakers using a 3.5mm to 2 rca + Y splitters. I notice some hissing noise which I expected. While I am listening to music or playing video, it's mostly not noticable.

While I am playing older games, not a problem but if I start playing a resource-hungry game, psu draws more power and the noise starts to irritate.

Should I buy a Dac, a ground isolator or a ci box to eliminate hissing completely? Which would be less expensive but still make the job done?

There are a few other things to consider. I want to be able to connect my powered speakers to Tv via tv's optical output and speakers' rca output. I bought a dac for it but it seems corrupt.

Also I want to be able to connect my powered subwoofer to Pc and if possible to Tv too, should I buy a multi channel (5.1) dac for it? If I just buy a stereo Dac, connect my speakers to it and then connect my subwoofer's rca line-ins to powered speaker's Xlr output using a Xlr to rca +Y spitter, will my subwoofer work?(without having to buy a 5.1channel dac)

So I want to be able to do all of the things which I mentioned, if possible I just want to buy just one device and accomplish all of these. What should I buy, which type of device?

When I ran into this I switched to shielded cables and a ground isolator. This happened at a flat I use to rent 14 years ago. When I got a house I ran dedicated circuits for the listening room. On my current Soekris DAC I use RCA out to XLR when I want to use a sub for more bass for a 2.1 setup. The XLR out on the DAC go to the Front L/F.

[AwArEnEsS]

Thanks for your answer.

On my current Soekris DAC I use RCA out to XLR when I want to use a sub for more bass for a 2.1 setup. The XLR out on the DAC go to the Front L/F.

Actually I wonder if I connect my powered speakers to the stereo dac's L/r outputs and then connect my powered subwoofer directly into my powered speaker's subwoofer output, would subwoofer work. The dac I have (which seems corrupt) and the dac which I have ordered don't have Xlr output, they just have L/R rca outputs and the other one has a 3.5mm output additionally.