Why headphones don't fit the stereo.
If you listen to music using headphones, you will see that the sound can be seen as coming out of your head. And when the instrument plays only one direction, you get an unpleasant sensation that the instrument is playing near your ear.
In a loudspeaker game, the audio section is naturally assigned to the center of the loudspeaker. If you live in a comfortable area, loudspeakers are usually separated by 45-60 degrees in a standard stereo set.
The main difference between a speaker and a headset is that with speakers, the sound from one channel reaches both ears (as you can see in Figure 1a below). When we have a headphone, we usually send a left-hand channel to the left ear and then to the right-hand one for the simple reason that it has two audio channels and two ears. But you may need to think about it further.