With the release of Windows Vista, some significant changes were made to the sound controls. The popular Stereo Mix feature is outdated and its use is no longer recommended. Let me remind you that this feature allows you to record sound coming from any application to the speakers. Now support for this feature depends on the hardware manufacturer. So how can we record streaming audio now? For this, Microsoft introduced a new standard feature - this is the "Speakers" input. What is the difference between them?
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.
In light of the above, the situation has changed for the better. Now you do not need to search for the right audio driver or change the sound card.