Question Side Surround speakers playing at the same time

Nov 12, 2021

This is my first 5.1 setup and I'm having an issue where both of the side surround speakers play at the same time when testing them via Windows.
I've tested both via the Windows Sound control panel (Right click audio device > Configure speakers) and via a Dolby 5.1 channel test file with MPC.

When I click the left side channel, both left and right will play the sound, and vice-verse. Is this intended? If not any idea how I go about fixing this?

My setup:
  • Monoprice SB-600 5.1.2 Dolby Atmos Soundbar with Surround Sound
  • Connected to 4k TCL Smart TV via HDMI Arc
  • Connected to my Nvidia GTX 1070 via HDMI 1 in (I also tried a gaming laptop with the same results)
I tried configuring the Nvidia audio device with the Windows default 5.1 setup, and also downloaded the Dolby Atmos app but both give me the same results.
I'm wondering if it's a Windows/Nvidia issue and I suspect the TV HDMI Arc connection is probably fine but I have no way to test it / get the test file onto the TV. Netflix seems to have removed their surround test videos.

If this is intended and the side channels are supposed to both play at the same then apologies for my stupidity here. :)
If not intended then any help here is greatly appreciated!