There are many options and it depends on your setup and your needs which one you use:
Here are four places where you can switch to Mono:
Make it Mono
the first step is to merge the 2-channel stereo signal into a mono signal
1 - Input Format
When you have stereo Audio Regions on a Track, you can set the Input Format (the circle buttons) on the Input Button to Mono. That merges the signal to mono. Using the File➤Export➤Region to Audio File will create a mono file.
2 - Audio FX Plugin (Mono) on Channel Strip
If option 1) is not possible because you have stereo Plugins on that Channel Strip that you want to keep, then you can add the Audio FX Plugin "Gain" at the last slot of the Channel Strip and set it to Mono. Now the Channel Strip has a two channel mono signal at its output. If you need that Gain Plugin on multiple Channel Strips, then keep in mind that you can with select all the Channel Strips and load a Plugin on Channel Strip and it will be loaded on all selected Channel Strips (Ad-hoc Group functionality). Or, you can load it on one Channel Strip, make the setting (switch to mono) and then option drag that Plgin to other Channel Strips.
3 - Audio FX Plugin (Mono) on Output Channel Strip
If you don't want to create individual Plugins on all the Channel Strips, You can also add the Gain Plugin on the Output Channel Strips and set ti to mono.
Export/Bounce
Once your signal is merged to mono, you have different options to export/bounce it to mono files.
A - Export Region
You can use the
File➤Export➤Region to Audio File command on individual Audio Region when you use option 1 and 2
B - Bounce Stereo Output Channel Strip
Use the "Split" option in the Bounce window and it will create two separate mono files for the left and right output channel, which are indentical at that point. Just use one of the files and toss the other redundant one.
C - Bounce Mono Output Channel Strip
With this procedure, you click on the Input Button of the Output Channel Strip. It toggles it between stereo (two circles) and one (one circle). Now you have two separate Output Channel Strips (one for the left output channel and one for the right output channel). the cool thing is that both Channel Strips have their own "Bounce" Button, when you use that button, you create a single one-channel audio file for the signal routed through that Output Channel Strip. I demonstrate that functionality in my new book "
Logic Pro X - Tips, Tricks, Secrets #1".
Here is a screenshot from that section