Edit: Unfortunately, the images originally included in this post are gone, because of hosting problems in late 2009. My apologies.
“So K.Mandla,” you say. “Those minimal setups are nifty, but where is the volume control?”
Ah, grasshopper. Watch closely.
Ubuntu installs alsa-base and alsa-utils by default (as part of ubuntu-minimal), and provided you didn’t rip them out when you built your minimal system, you still have a nifty ncurses application for modifying sound settings: alsamixer.
Start a terminal and type in alsamixer and you get this:
“Ech! It’s ugly!” you say. Yeah, I suppose so. But look closer. Is it really that much different from Gnome’s volume control panel? or XFCE’s volume control? All the same controls should be there. Navigation is with the cursor keys. Press M to mute a channel, or to unmute it. Settings take effect immediately. Press Escape to quit.
So for you Openbox fanboiz who, like me, don’t want to add a lot of bulk to your system, throw this into your ~/.config/openbox/menu.xml file anywhere you deem appropriate.
[item label="Alsa Mixer"]
urxvt -e 'alsamixer'
Swap out all the left brackets for less-than signs, and the right brackets for greater-than signs. Bingo: volume control.
Note that I use urxvt; your choice of terminal will vary and the flag to execute a command within the terminal might be different too. I know for xfce4-terminal, you’ll want the -x flag, instead of -e.
P.S.: Don’t forget that most audio and video applications, like XMMS and RealPlayer, adjust the PCM line when you change the volume. So if your PCM level seems to move around behind your back, it’s probably because you changed the volume while you were listening to The Very Best of Engelbert Humperdinck.