Trying to Split tracks-stereo to mono

How can I set up to record just in mono tracks? Can I save an audio file that was originally stereo and mix those two tracks to one mono file? Can’t find any tutorials in the manual or the FAQs about this procedure.

Why does ACX prefer us to record audiobooks in mono files? What if one has music and sound effects with a project? Can all that really be melted down into one audio file, and how is that a better listening experience than a stereo production?

Set the “number of channels” to “1 (mono)” in the device toolbar
Note that if you are using a 2 channel sound card / audio device, the “mono” input is usually the “Left” channel (may be marked as “Channel 1”).

Yes you can do that.
There are two approaches:

Method 1
Split the track into two mono tracks, then delete the track that you don’t want.
This is the method that you should use when the “stereo” track was recorded from a mono input source (such as from a single microphone).

Method 2
Mix the stereo track to mono.
This is the method that you should use when it is a “true stereo” recording (when some sounds are more to the left and other sounds are more to the right).

MP3 encoding always loses some amount of sound quality. The more data “bits” that are available, then the less the quality degradation. For a given number of “bits per second” (or “kilobits per second” kbps), mono gives better sound quality. If there is only one audio channel (mono), then the encoding can use all of those data bits for that one channel. If there are two channels (stereo) then the encoding has to share the available bits between the two channels, so there are less bits available per channel.

If stereo music is important, then use stereo and distribute through a service that supports stereo (not ACX).