Thank you for reporting this bug to Ubuntu. Ubuntu 12.04 (precise) reached end-of-life on April 28, 2017.
See this document for currently supported Ubuntu releases: https://wiki.ubuntu.com/Releases We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test. ** Changed in: pulseaudio (Ubuntu) Status: Confirmed => Incomplete -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to pulseaudio in Ubuntu. https://bugs.launchpad.net/bugs/994162 Title: cmi8738 very loud on surround Status in pulseaudio package in Ubuntu: Incomplete Bug description: Release ---------- Ubuntu 12.04 LTS Package Version --------------------- pulseaudio 1.1 Hardware ------------ Generic C-Media 8738 7.1 5.1 Speaker system pci:5 description: PCI bridge product: MCP67 PCI Bridge vendor: NVIDIA Corporation physical id: 8 bus info: pci@0000:00:08.0 version: a2 width: 32 bits clock: 66MHz capabilities: pci ht subtractive_decode bus_master cap_list resources: ioport:d000(size=4096) *-multimedia description: Multimedia audio controller product: CM8738 vendor: C-Media Electronics Inc physical id: 8 bus info: pci@0000:01:08.0 version: 10 width: 32 bits clock: 33MHz capabilities: pm bus_master cap_list configuration: driver=snd_cmipci latency=32 maxlatency=24 mingnt=2 resources: irq:19 ioport:d800(size=256) Configuration ----------------- "Sound Preferences -> Output" is set to use "Analog Surround 5.1 Output" for the CM8738 device Expected Result --------------------- The master volume should control both the front and the rear and the center/sub speakers Actual Result ----------------- The master volume control only controls the front speakers. The real speakers are set to FULL volume - very loud and can't be changed. Other ------- BTW: In 11.04 soundcard works great but after update to 11.10 and after that to 12.04 there is problem again. Additional info from recursice bug from 10.10: https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/632389 A bit of searching turned up the following text at http://alsa.opensrc.org/index.php/Cmipci#4.2F6_Multi-Channel_Playback "WARNING When "Four Channel Mode" switch is off, the output from rear speakers will be FULL VOLUME regardless of Master and PCM volumes. This might damage your audio equipment. Please disconnect speakers before your turn off this switch. " If I didn't have a separate master volume switch on the speakers themselves, this would have happened to me. Being as Sound Preferences itself doesn't seem to have the "4 channel mode" switch, I installed gnome-alsamixer. This does show the "Four Channel Mode" setting. However, when pulsedaemon is running, it is not possible to select the switch. If I kill pulsedaemon, the switch can be enabled and the speakers act as expected (I used speakertest to prove this). This problem has existed ever since the introduction of Pulse as the default. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/994162/+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
