Line Out (green) Audio does not seem to work

I am using Fedora 39 KDE Spin. I have a set of desk speakers, which includes a left and right speaker along with a sub-woofer. I have it plugged into the “Line Out” and in PulseAudio Volume Control, a device shows up under “USB Audio” as “Speakers”. I have been trying to get this functioning properly for about an hour and a half just today. I can pretty much use any other kind of speaker such as my USB headset, PS5 Controller, all my monitors, and even if I plug in the speakers to my headphone jack on the front of my pc tower (This device seems to also be under “USB Audio”).

I have my setup dual booted with Windows, and my line out works as expected.

Any suggestions?
Thanks

Edit:
Probably would be important to include this, but all three speakers (left, right, and subwoofer) all are connected through the one green Line In plug.

It’s a common problem with Linux – hardware is often designed to work with MS Windows (or another non-free OS) first and support for Linux (if any) is an afterthought.

Excerpt from kernel.org – More Notes on HD-Audio Driver:

One of the most frequent (and obvious) bugs with HD-audio is the silent output from either or both of a built-in speaker and a headphone jack. In general, you should try a headphone output at first. A speaker output often requires more additional controls like the external amplifier bits. Thus a headphone output has a slightly better chance.

See the above link for more information about the problem and some possible workarounds. Many people find it easier to purchase hardware that works with Linux than it is to make Linux work with all the hardware.

I have an identical setup I think. From my MoBo built in line out (Intel HD audio chip) to my (some unknown brand of amplified sub-woofer with two sat spkrs attached) and it works. Some apps have difficulty though, and not consistently for me, so it is hard to figure out why. Generally it works, but when it doesn’t I open Gnome Settings and Test the output of the line out device, it works after that. Another thing I have found is some apps are turned way down which appears as the output is not working.

I don’t think this is the right device.

Why are you using this? It’s not required with Pipewire and Wireplumber.

Although not required pavucontrol is very useful and in some cases can be used to solve audio issues.