The Mono/Stereo posting may benefit from further thought.
When a sound is heard, it is heard in stereo, by two ears. So all sound is stereo for a person with normal hearing.
Some sounds come from one point source, but very few. For example, a piano is a sort of single source, so it is played in mono in effect. So whatever the recording engineer does, the original piano sound is mono, but heard by stereo ears.
However, we need to define our terms. For example, a piano has many strings, so each string is a mono source. Far beyond two channels. Then we have to remember that sound isn't a straight line; it goes around corners, echoes, bounces of objects on its way from the mono string, to the stereo ears.
So let's not worry about mono versus stereo. Our ears make everything stereo.