I am having trouble to activate 5.1 sound on Ubuntu. My motherboard have integrated sound card ( nForce chipset ) and under Win is working fine ( Realtek jack recognition software ). On Ubuntu, i can hear only 2 speakers ( front left & front right - which are connected on out port ). Other 4 speakers ( central + subwoofer are connected on mic port, and rear speakers are connected on line in port) are dead. I do not know how to force these 2 ports to work as output. All topics on Ubuntu forums didn't made result for me. ( manually config, alsa drivers, pulse audio drivers, nVidia volume control...) Can anyone help, please?