Mark,

As far as I know, there isn't any software known as " Windows Sound Volume Mixer". What controls you have access to will be dependent on your sound card and any software that came with. Standard Windows volume control looks like this:



As you can see, no bass or treble controls. There's some more information here that might help:

http://media.virtuosi.fi/users/pdonner/winmixer.htm  

Dave

The advanced aspects of the mixer device may be activated from dedicated buttons which must be activated through a toggling menu command. That is, the user must have advanced knowledge of the application to be able to operate the mixer's advanced features. It is unfortunate, that some of the advanced features may still remain hidden from those end-users, who only rely on the system supplied mixer application. This is the case with the Front Rear Balance control of the SoundBlaster Live! example, which remains hidden in the Advanced controls dialog.

 this dialog was on top of the bass and treble picture. It states that you have to have advanced knowledge of the application to be able to operate the mixer's advanced features(bass and treble?). Whats the big secret?

mark

I wouldn't think theres any big "secret"  Have a fiddle with it and see what happens but if you're not sure about changing settings though, don't!