I have an Alienware MX17R3. It contains the following soundcard built in:
Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 05)
It is not correctly detected by default in the conf files. I have also tried manz options that I have found on the net without any success. Anybody could help me to make it work with my 5.1 external speakers?
Now, it works as mono and uses subwoofer to give mono sound (front-left channel) only.
