On supported motherboards and having the Realtek Driver installed, the Realtek Audio Control should be pre-installed (on my case it has the MSI branding).
Just set the settings as seen from the screenshot below:
![Realtek Audio Control Settings](/combine-front-and-rear-output-jacks-realtek/realtek-audio-control-setting.png)
Realtek Audio Control Settings
Now hopefully you can hear the same audio from two devices, otherwise check your device output settings.