How to create dual mono in a multicam clip from an external mono audio track?

Hi.  Long time reader.  First time question.I have a FCPX Multicam Clip audio question.I often film multiple angles on a single speaker for interviews, and find multicam clip editing very useful.  In these cases I use an external audio recorder to record a single mono track.  So I end up with an audio track not connected to any video tracks, and so use the Multicam to sync and then edit.Does anyone know a way to make the mono audio track into dual mono in the Multicam clip, so the audio in my finished video isn't mono and only heard on one side of headphones?  I know that the type of question has been solved by people for mono audio attached to a video file, by changing the audio on the video file from  stereo to dual mono BEFORE creating a multicam clip.  However I cannot find a solution for creating dual mono from a mono external audio recording.There are two other strange things about this mono in multicam clip question.1. I'm pretty sure I have done this exact process for a number of years with no problem, but have only come up against the mono only audio issue, so maybe there has been a change in a software update - ie FCPX somehow used to automatically create dual mono at some point?2. In my Project Timeline, when editing a multicam clip with the mono only audio problem, the audio meters show two channels of identical audio!  But then the exported file only has mono audio!Thanks for any help,Dan

A single mono track should play back through both speakers in a stereo setup.

Dual mono means that you have two, separate mono channels/tracks. For example, when recording dialogue, you might have a mono source (microphone) that you record to two channels/tracks, each at a different level (the lower level often used as a "safety" for very loud passages where the recordist isn't able to adjust overall levels).

There could be a configuration issue (look at the audio inspector). Do you have an external audio device that feeds your speakers?

You seldom, if ever, use two copies of a mono channel/track, especially if they are from a different source. Phase issues can cause havoc as a result.

[In future posts, it would be helpful if you break up your text into separate paragraphs. It makes it easier to follow. Thanks.]