Adjust PCM volume?

The default sounds levels of master volume 100%, application/stream 100%, are too loud through my headphones.

I can adjust applications or the master volume down, but if a new application makes a sound it is deafening. Also The master volume has reset to 200% before when fiddling with the equalizer - so I'm kind of scared of relying on that now

At the moment I adjust the master, but I have it close to 25% meaning a slight increase will usually make it too loud.

Previously when using ALSA, I could have the PCM volume set to 25% then adjust the master volume from 0-100%. However now in pulse audio if I set the PCM volume and then change master volume the PCM will be reset to 100%.

Any suggestions? I've pretty much stopped listening to music because I'm (some what irrationally) scared of it now

From Ubuntu 9.10 the GNOME mixer behaviour changed thus making sound mixing done by Pulse Audio inconsistent. Depending on the distribution version you run you may also suffer from this. According to bug #322909 #30 it may help to ignore PCM volume settings rather than mergin them by editing /usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf.common as root and changing the entry

[Element PCM]
volume = merge

to

[Element PCM]
volume = ignore

After that a system reboot is needed for changes to take effect.

There may be other options in this file (that controls ALSA/Pulseaudio) you could try out if the above does not help. There are some explanatory notes on possible settings.

Don't forget to backup the original file before you apply changes.

In Ubuntu 16.04, I edited the file /usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf.common.

In line 128 I changed volume = merge to volume = ignore and it worked perfectly.