I have a computer that's running some software developed in our company, that also plays some sounds. For some reason the volume of the sound made by the software isn't affected by the PCM setting in alsamixer, only Master and Speaker have an effect. And somehow playing audio in a browser (iceweasel) is affected by the PCM volume level and with PCM at 100% it's a lot louder than the sound played by the software. There's no pulseaudio used, also no gnome or anything else getting in the way. The application is using the sound device plughw, not "default".
Why does the PCM level affect the browser audio volume and not the application? Also, it seems to depend on the computer used, since on most computers PCM does work, but not on some Asus models.