Determining mono or stereo export audio

Hello

I’m using Audacity 2.1.2 on Windows 7.

I noticed that in exporting audio for different projects in a wave or MP3 format, sometimes I get an automatic proposal for one mono track, sometimes for a stereo track.

I checked export preferences, but I see no option to always have a stereo output for exports. Is this possible? Is there something wrong with my project when it only enables a mono export?

Thanks

Anne

The general rule is:
If all of the audio in the Audacity project is mono, then the exported file will be mono.
If any of the audio in the Audacity project is stereo, then the exported file will be stereo.

A “stereo” track in Audacity may be either:

This is what a typical stereo track looks like:

The exception to the rule is if you are exporting to a format that is mono only, such as “AMR (narrowband)”.
(In the next version of Audacity (2.1.3), there will be an option for MP3 export to force the file to mono regardless of whether the project is mono or stereo)