Pulseaudio volumes are not even close to be in sync with the alsamixer levels. After experimenting for a while I managed to max out the pulseaudio master channel (internal audio analog stereo) in kmix while alsamixer's master (on HDA Intel, not the pulseaudio device) was only at 10/100. Another strange thing is that when I move an application-specific slider, the master level changes as well. There is some connection between the levels (when I move a slider in kmix/"pulse", some alsa levels change) however I have no idea about the nature of that connection. Version-Release number of selected component (if applicable): pulseaudio-0.9.21-6.fc13.i686 KDE 4.4.3 HW is Realtek ALC882 HD audio. PS: volume levels were strange on Gnome as well (especialy when trying to adjust 5.1 levels separately), but not to this extent.
Yes, PA unifies the dB scale across all sound cards. This is a feature, not a bug: http://pulseaudio.org/wiki/PulseAudioStoleMyVolumes http://pulseaudio.org/wiki/WritingVolumeControlUIs
I was talking about KMix's controls and KDE integration, not PA itself. Having KMix's "PA Master" (and all other controls of KMix) maxed out while there is almost no sound, is _imho_ not a feature but a bug. Feel free to disagree, however.