Sound issues with my TV, need logistical help!

This can get confusing to explain, so I'll try to lay it out as basic as possible.

The speakers on my TV are dying, and they sound awful. However, I just got new speakers for my computer that are amazing, so I decided to split it with the TV/computer. Here's what I did:

I bought a splitter for the cable. One standard 3.5mm is going into my computer, and the other is going into an adapter that turns it into an RCA (white/red) cable. I've plugged the RCA cable into the back of my TV under "audio out".

The problem is, nothing is exiting the speakers when the Xbox is on. My computer still puts out sound, so I know the splitter worked, but the Xbox refuses to play nice. I realize HDMI is designed to carry sound and video, but wouldn't the TV override that
with an "audio out" port being occupied? Does anyone have any idea what I'm talking about, or any ideas? Much appreciated!

:)

 

Can someone help me

I recently send my console to microsoft for repairs because my games weren't being load and played. It was repaired and now I'm having issues with my HDMI output and their is no sound coming from my console during game play. I know is not my tv because I
heard sound when I'm watching live tv..... Can someone help me!!!!

 

Sound issues

My sound works fine on my tv at home, but on my tv at my Aunt’s house nothing, we’ve tried everything help! It’s an RCA tv ...sound works fine with the Roku and worked fine before. What are we missing?