Can I make a 5.1 surround sound mp3 in audacity?
Audacity can only play mono or stereo, but you can “Export” multi-channel audio files. To do so, you need to have a project with multiple tracks, and enable “Advanced Mixing Options” in Preferences. See:
https://manual.audacityteam.org/man/import_export_preferences.html
and
https://manual.audacityteam.org/man/advanced_mixing_options.html