xFXMixer is a free and very powerful application, intended for the audio professional, that lets you create custom mixers combining different lines and controls from all your sound cards into an easy to use integrated interface.
When you have multiple sound cards and sound cards that provide many lines and controls, xFXMixer will let combine those settings that you access the most into the interface.
With the mixer application included with Windows you will have to perform multiple clicks to set simple settings such as the recording source, control the bass or treble or mute some line... and this gets even more tedious when you have several sound cards.
xFXMixer will let you create your own set of custom mixers where you will be able to combine those controls that you use the most and access them with a single click!