I have a run of the mill Realtec sound system and it's control center offers, Stereo, Quadro, 2.1 .... etc. Speakers are 2 + 1, ie. it's connected only to Front speakers out on the computer so only Stereo settings are driving everything and it's set to stereo. With 2.1 setting I loose Bass because it has it's own jack on the MB.
I have a 2.1 speaker system on my PC. It is ONLY connected to the GREEN speaker jack on rear motherboard I/O panel. The speaker type is set to "Stereo". This is the usual setting and what is available for RealTek systems.
If you have a 5.1 system, for example, then there are three connections to the audio I/O panel.
Yes, that setting will give you all available sound to one (Green) jack. If your speakers/headphones don't have expected sound, it's their fault, can't do much about it.