I've tried every option there is on my TV for sound. changed "digital audio out" from "PCM" to "Dolby Digital". turned off the built in speakers on my TV. "Analong Audio Out" didn't seem to affect anything. Turning "SUS TSHD" on and off.
I tried VLC default settings to play a test surround sound file, but it didn't work. I only heard sound from my front left, front right and center speakers. I even messed with advanced settings and it didn't help.
You have to configure the sound system in Control Panel > Sound > Select the audio device and then click configure. If the problem still exist then reinstall the sound drivers and as you said your PC is new then you can also contact the dealer from where you buy your Computer because your Computer is in warranty.
I un-installed and re-installed the sound drivers. Then I went to Control Panel > Sound > AMD HDMI Output > Configure and I still only got an option for stereo.
I did a little research myself, try going to the Catalyst Control Center and selecting the TV as the output device. Can you modify the sound settings there? (sorry, no longer have CCC on any system so I can't walk you through it)
I'm not seeing any option for setting my TV as output device. I see an check box to "Add 1080p60 format to the Display Manager (NTSC)" but that's about it. And I don't want to click it because it says it could possibly damage my TV. Which, I'd rather not do.
edit: messed around with the control center some more. still can't find anything about audio. I was hoping to get this up before Christmas, so when I get some games I can play them in full surround .. But maybe not :/..