What does mixer pcm command do?

[kriptomahsun]

I've just came accross these commands randomly. It was by default mixer pcm=0.45 but when I set something like mixer pcm=0.25 the sound is still the same, but sound sounds like cracking a little.
What does it do actually?

 

[SirDice]

You could try reading its man page of course, most commands have one.

mixer(8)

 

[LibreQuest]

My pcm vol on my laptop for some reason sets to .60 so I set it to 100. :/