Ubuntu 18.04 5.1 front speakers not working

I have recently installed Ubuntu 18.04 on a new machine and plugged my 5.1 surround sound speakers into it and have changed the audio profile:

However when I test my speakers all but the front left and right are producing sound and I am not sure what I should look into in order to resolve this?

1 Answer

Looks like your system tries to play in 3.1 surround mode.

Try to install PulseAudio control panel:

sudo apt install pavucontrol

It gives you more options. Maybe there is an option to choose 5.1 surround.