the major problem is how pulseaudio know when the headphone or speaker share the same volume control if the driver create "Bass Speaker Volume"
in your case the subwoofer is connected to the mono pin which downmix stereo to mono the driver just copy front channel to both DAC instead of using 4 channels output some asus notebook can also connect to sonic master external subwoofer https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1040873 according to the user comment. the subwoofer seem only use right channels of the stereo complex in this case they need pulseaudio to mix left and right to provide signal to the external subwoofer http://lists.freedesktop.org/archives/pulseaudio-discuss/2013-December/019654.html e.g. a desktop with 3 audio jack at rear panel and 6 channels codec (e.g. alc662) the rear line out and front panel headphone have to share the "Front Playback Volume" control since multi channel to support 5.1 is more important than the "headphone playback volume" but a desktop with 6 audio jacks at rear panel and 10 channels codec rear line out jack use Front Playback Volume" exclusively because there are enough volume controls for each output jacks and headphone use "headphone playback volume" there are different case for a 4 channels codec e.g. those thinkpad with dock station are also have three output ( headphone, dock headphone and internal speaker) -- 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/1274401 Title: Internal sub-woofer on Asus G75VW laptop doesn't work. Status in “alsa-driver” package in Ubuntu: Incomplete Bug description: The internal sub-woofer does not work on the Asus G75VW series laptop. It has no usable controls in the Sound Settings window and sound does not come from the internal sub-woofer when testing it with Rhythmbox, youtube.com video and audio, or Audacious. Ubuntu Version: Ubuntu 12.04.4 LTS - Linux Version - linux: Installed: (none) Candidate: 3.2.0.58.69 Version table: 3.2.0.58.69 0 500 http://us.archive.ubuntu.com/ubuntu/ precise-updates/main amd64 Packages 500 http://security.ubuntu.com/ubuntu/ precise-security/main amd64 Packages 3.2.0.23.25 0 500 http://us.archive.ubuntu.com/ubuntu/ precise/main amd64 Packages ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: linux-image-3.2.0-58-generic 3.2.0-58.88 ProcVersionSignature: Ubuntu 3.2.0-58.88-generic 3.2.53 Uname: Linux 3.2.0-58-generic x86_64 NonfreeKernelModules: nvidia AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24. ApportVersion: 2.0.1-0ubuntu17.6 Architecture: amd64 ArecordDevices: **** List of CAPTURE Hardware Devices **** card 0: PCH [HDA Intel PCH], device 0: VT1802 Analog [VT1802 Analog] Subdevices: 2/2 Subdevice #0: subdevice #0 Subdevice #1: subdevice #1 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: crosswalk 2018 F.... pulseaudio /dev/snd/controlC0: crosswalk 2018 F.... pulseaudio Card0.Amixer.info: Card hw:0 'PCH'/'HDA Intel PCH at 0xf7310000 irq 44' Mixer name : 'VIA VT1802' Components : 'HDA:11068446,10431487,00100000' Controls : 31 Simple ctrls : 18 Card1.Amixer.info: Card hw:1 'NVidia'/'HDA NVidia at 0xf7080000 irq 17' Mixer name : 'Nvidia GPU 42 HDMI/DP' Components : 'HDA:10de0042,10432119,00100100' Controls : 12 Simple ctrls : 2 Date: Thu Jan 30 02:12:06 2014 HibernationDevice: RESUME=UUID=9e120375-84ba-4393-a169-35f243c10efa InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120823.1) MachineType: ASUSTeK COMPUTER INC. G75VW MarkForUpload: True ProcEnviron: TERM=xterm PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 EFI VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-58-generic root=UUID=eb4a342d-0d1e-421f-a355-5fb8eb65bb15 ro quiet splash vt.handoff=7 PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: Daemon not responding. RelatedPackageVersions: linux-restricted-modules-3.2.0-58-generic N/A linux-backports-modules-3.2.0-58-generic N/A linux-firmware 1.79.9 SourcePackage: linux StagingDrivers: mei UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 08/21/2012 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: G75VW.218 dmi.board.asset.tag: ATN12345678901234567 dmi.board.name: G75VW dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: 1.0 dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: ASUSTeK COMPUTER INC. dmi.chassis.version: 1.0 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrG75VW.218:bd08/21/2012:svnASUSTeKCOMPUTERINC.:pnG75VW:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnG75VW:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0: dmi.product.name: G75VW dmi.product.version: 1.0 dmi.sys.vendor: ASUSTeK COMPUTER INC. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1274401/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
