How does the sound card detect what sound system its being plugged in

[darkmwar]

Hi, I am about to hook up a 4.1 sound with a 2.1 sound on to my sound card, making it a 5.1 ( with the 2.1 as center).
How would the sound card detect each system being a 2.1 or 4.1? How does it know which system is plugged in to which port?

 

[Emperus]

The sound card cannot detect that. It just offers the playback depending on the speaker profile you select in the windows sound device properties.