I noticed that the number of channels muted at once may depend on the port chosen in pavucontrol's Output Devices tab. In my system, if I choose "Headphones (plugged in)", muting affects only to ALSA tracks called Master and Headphone. If I choose another port, muting affects to Master, Headphone and Speaker.
$ lsb_release -r Release: 14.04 $ lspci|grep Audio 00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 02) ** Summary changed: - Pulseaudio: incoherent muting of GStreamer channels (mutes master, headphone and speaker, but unmutes only master) + Pulseaudio: incoherent muting of ALSA channels (mutes master, headphone and speaker, but unmutes only master) ** Changed in: pulseaudio (Ubuntu) Status: Incomplete => Confirmed ** Changed in: pulseaudio Remote watch: freedesktop.org Bugzilla #70865 => freedesktop.org Bugzilla #79911 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to pulseaudio in Ubuntu. https://bugs.launchpad.net/bugs/1254884 Title: Pulseaudio: incoherent muting of ALSA channels (mutes master, headphone and speaker, but unmutes only master) Status in PulseAudio sound server: Unknown Status in pulseaudio package in Ubuntu: Confirmed Status in xfce4-volumed package in Ubuntu: Invalid Bug description: with certain audio hardware (those where alsamixer shows separate "headphone" and "speaker" channels) pressing of the mute button on laptop keyboards causes mute of all three channels: master, headphone and speaker. unfortunately, pressing the button again to unmute (or deselecting mute in the xfce audio mixer panel applet) unmutes only the master channel, leaving headphone and speaker muted. there is no other way than opening alsamixer in a terminal (or open mixer controls from the applet) and manually clicking the two remaining channels to unmute. ProblemType: Bug DistroRelease: Ubuntu 13.10 Package: xfce4-volumed 0.2.0-0ubuntu1 ProcVersionSignature: Ubuntu 3.11.0-13.20-generic 3.11.6 Uname: Linux 3.11.0-13-generic x86_64 NonfreeKernelModules: wl ApportVersion: 2.12.5-0ubuntu2.1 Architecture: amd64 Date: Mon Nov 25 22:33:06 2013 InstallationDate: Installed on 2013-11-07 (17 days ago) InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1) MarkForUpload: True SourcePackage: xfce4-volumed UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/pulseaudio/+bug/1254884/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp