do the subwoofer need both left and right channel ? try hda-analyer to change the volume sliders of audio mixer which is connected to subwoofet (node 0x0d ?）
speaker-test -c2 -t wave -D hw:0,0 do it work with 2.1 mode ? https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1286021 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to alsa-driver in Ubuntu. https://bugs.launchpad.net/bugs/1302090 Title: Dell Alienware 14, Speaker sound output is mono until a headphone jack is plugged Status in “alsa-driver” package in Ubuntu: New Bug description: Here's the required release and package information: Description: Ubuntu Trusty Tahr (development branch) Release: 14.04 Package: linux-image-extra-3.13.0-19-generic Version: 3.13.0-19.40 When playing audio through speakers on my Alienware 14 2014, the sound output is in mono until I plug a headphone in any of the two available headphone jacks (obviously, the auto-mute option must be disabled). When I do so, the sound starts to play in stereo. I would love the sound output to be stereo by default and not be forced to plug anything to achieve that. Attached is the alsa-info.sh output for my machine. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1302090/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
