Version:            (using KDE 4.1.3)
Installed from:    Unspecified

Maybe I will start by explaining why I do need such a strange feature :)

I've got a 6-channel sound card. Both my headphones, and regular stereo speakers (2.0) are connected to it all the time. Sometimes I want to use just headphones (to listen to the music while someone else is watching the TV the next room), and sometimes the speakers (when nobody is at home, or when I want to present new music to someone). And sometimes I do need to switch between those two devices. Usually, I just use some commandline mixer tool, and assign it to some keyboard shortcut - to mute headphones and unmute speakers with one combination, and do the opposite with other.

I think it would be nice to have some kind of GUI for similar things in kmix - I think the most universal would be the ability to define some kind of 'presets', which would apply to just selected lines and/or mute/unmute checbkoxes.