This worked for me after the Windows 10 Creators Update hosed my audio and no other fixes above worked. (Windows 10 Home, Version 1803, OS build 17134.48, Dell XPS 8700, 64-bit).
1. Open the Realtek HD Audio control panel. If you can’t find it, try going to C:\Program Files\Realtek\Audio\HDA and double-click on one of the .exe files. The one that worked for me was RtkNGUI64.exe, which brings up the Dell Audio manager on my system.
2. Click on Advanced.
3. Click on Jack Information.
4. Click on the Font Panel radio button.
5. Click on Front Speaker Out.
6. Click OK.
7. Adjust system volume if necessary by clicking on the Volume Control icon (speaker) at bottom left of your desktop. Right-click to bring up the Volume Mixer to adjust volume levels for individual apps.
Hope this helps.