Having an issue with sound at the moment. I am trying to configure my 5.1 surround sound but it will only work on the Front left and Front right speakers. On the back of my motherboard I have 3x3.5mm jacks which I have connected the speakers to although these are not the right ports.
I want to "assign" the three ports on the back to each output (Sub and centre, Left and right, and rear left and right) although I'm not sure how to do this. My audio is ALC889 from Realtek and am using Ubuntu 12.04 with all updates installed.
pavucontrol, run it, and see the settings in the "Configuration" tab. The commandline way is runningalsamixerin a terminal, select the right sound card and change the channel mode. Similar to most right mixer setting in this screenshot. – gertvdijk Nov 16 '12 at 21:13