Why can I still hear music when the PCM volume is MUTED?

[Rodd Clarkson]

Hey All!

I'm using Rhythmbox to play OGGs with a Intel ICH6 (Alsa Mixer) sound
card and when I mute the PCM volume control (either in the panel, or in
the Volume Control applet), I can still hear music.

What gives?  There doesn't seem to be any option to choose what channel
Rhythmbox uses and the PCM volume certainly seems to control the volume
of Rhthymbox.

Setting the volume to zilch in Rhythmbox 'mutes' playback of music, but
no the PCM volume control.

Also, on a related note, is it possible to 'tie' together the Master and
Master Mono volumes.  On my laptop (which has a sub woofer) the Master
Mono volume controls the volume of the sub woofer, so it makes the use
of the volume up / volume down / mute buttons useless as they only turn
up and down (or mute) the master channel, and not Master Mono.

On thought: These buttons are assigned using gnome (System > Preferences
> Keyboard Shortcuts) so maybe gnome should be adjusting both volumes if

they exist?

Rodd