<div dir="ltr"> > > ><a href="http://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/Developer/Clients/WritingVolumeControlUIs/" target="_blank"> http://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/Developer/Clients/WritingVolumeControlUIs/</a> > > As I already wrote, the way it is today, if I set 100%/0dB either with > the GNOME volume control, "alsamixer -D pulse", or "pactl > set-source-volume 2 100%", the result is 30dB Capture + 24dB Boost, > which is *not* maximum level. So the user is currently not correctly > informed about the "real 0dB", even if you factor in the boost. <a href="http://freedesktop.org/software/pulseaudio/doxygen/volume.html" target="_blank">http://freedesktop.org/software/pulseaudio/doxygen/volume.html</a> pulseaudio documentation/wiki on volume only mention sink > > > However, for line in, the jumpy behavior of the current input control > would be even worse than for the Mic. My guess would be that for line > in, Boost had better be set to 0dB all the time, and "real 0dB" would be > "30dB Capture + 0dB Boost". You just gave another argument for not > merging "Mic Boost" into the overall volume. How did you add Line in support ?1) use hint add_jack_modes = 12) retask mic in jack to line in jack by early patching <a href="https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/tree/Documentation/sound/alsa/HD-Audio.txt">https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/tree/Documentation/sound/alsa/HD-Audio.txt</a>- add_jack_modes (bool): add "xxx Jack Mode" enum controls to each I/O jack for allowing to change the headphone amp and mic bias VREF capabilities - line_in_auto_switch (bool): enable/disable the line-in auto-switch feature; default false For line in recording, user expect pavucontrol provide a point at the volume slider which set Capture Volume and Line Boost at 0dB and no pulseaudio software volume similar to spdif passthrough to prevent clipping occur <a href="https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/log/sound/pci/hda?qt=grep&q=mic+boost" target="_blank">https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/log/sound/pci/hda?qt=grep&q=mic+boost</a> HDA driver have quirks about limiting the internal mic boost, The base volume of pulseaudio source is not constant any more <a href="https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/hda?id=3e0d611b2045b230c3acfb05c3b5ce53b09f6cdd" target="_blank">https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/hda?id=3e0d611b2045b230c3acfb05c3b5ce53b09f6cdd</a> </div>