Windows 10: Line-in doesn't playback in selected Playback device

Here are my "relevant" system specs:
CPU: 5960X
Motherboard: ASUS Rampage V Extreme

This seemed to have worked fine under Windows 7, but it stopped working awhile ago, I "think" about the time I upgraded to Windows 10. My Line-in will not playback any audio through my headset, I'm looking at my Recording Devices and I notice that the microphone on my headset is receiving sound when I talk into it (the volume bars increase/decrease depending on how loud I talk), but after plugging my monitor into my Line-in and also trying my phone, I cannot seem to get more than 1 bar of sound. I tried two different cables, same results. I know for a fact that Realtek HD is detecting when I plug something into the port, as SupremeFX appears and wants me to confirm which port I plugged something into.

Can someone help me on the issue?

:)

 

How do I set up my bluetooth speaker?

That is what I have been trying to tell you...When I right click the volume button and select Playback Devices. The Bluetooth speaker doesn't appear, although it says it's connected in settings and in the action center. It does not appear in Playback
Devices.

 

Output audio to multiple devices in Windows 10

I am running a MacBook Pro 15" (late 2011) which has BootCamp enabling Windows 10 Evaluation Copy 16232.rs_prerelease.170624-1334 (Windows 10 Pro Insider Preview).

I do not see the ability to select any of your suggested recording devices ("Wave Out Mix" ... "Stereo Mix") when selecting any of the "Speakers" from the Playback tab as you suggest. My list of Playback devices shows the MacBook (internal speakers), my
Display's audio, the Line Out as well as my Wireless Headset.

It would be nice to simply select playback to more than one device (and control its total output) directly from the Volume Control box provided by a right click of the Taskbar icon.