Windows Vista has made some significant changes to the audio controls. The popular "Stereo Mix" feature becomes obsolete, so how can we record streaming audio? The new feature introduced by Microsoft is the "Speakers" input. What's the difference?
Stereo Mix is a feature of sound card driver. It mixes together audio streams at the hardware level.
Speakers is a feature of Windows. It mixes audio streams at the software level before they reach the sound card.