Question Radio static noise when hooking up monitor to speakers

[ThomasKinsley]

TL;DR: I have a persistent static sound playing through my speakers when connected to my audio-out port on my monitor. In specific situations the static noise is affected by mouse movement, keyboard keypresses (keyboard is wired), and touch screen input.

Long version: I am using a Monoprice Crystal Pro 27'' 4k monitor and Logitech Z623 2.1 speakers. Here are the different scenarios in which they produce static:

1) Monitor > speaker (aux port) > PC, 2) Phone > monitor > speaker, 3) Monitor > phone > speaker (phone has a 3.5mm jack) and 4) Monitor > phone > 3.5mm adapter > RCA ports on the speaker's subwoofer.

Here are the situations in which I get no or minimal static:

1) Phone > speaker's aux port using the same 3.5mm cable 2) Laptop > speaker 3) Earbuds > monitor > PC 4) Earbuds > phone > monitor 5 PC > speaker

How can I get the monitor and the speakers to play nice together?

P.S. I don't know if this will help, but the speakers have always had an issue with "temporary" buzzy noise since the beginning. If I touch the power button it pops and crackles. Other times I need to give the cables a little twist and buzzing goes away, but that doesn't work at all with this issue with the monitor and is a different noise. Everything is connected to the same powerstrip. I tried connecting my speakers to a different outlet, but it produces the same results listed above. I'm guessing the problem is electrical interference with a possible ground loop issue.

 

[ThomasKinsley]

I know the connections are confusing, so here is a diagram for the situation. Red produces the noise, green does not.

 

[Unolocogringo]

So why are you connecting your speakers to the monitor instead of the computer.
The signal from there is now going through 2 amps. The one in the tv and then the one in the speakers.
Not a good setup.
The monitor out is for headphones not a line level out for amps.

 

[ThomasKinsley]

So why are you connecting your speakers to the monitor instead of the computer.
The signal from there is now going through 2 amps. The one in the tv and then the one in the speakers.
Not a good setup.
The monitor out is for headphones not a line level out for amps.

Great question. The speakers are also connected to the computer. My plan was to get my PC speakers to seamlessly switch between a desktop PC and a laptop/Android DeX setup with one USB-C cable charging the mobile device while displaying audio and video. I was hoping the monitor could pass the audio signal along, but that sadly appears to be a problem.