I am confused, because “export selected tracks” doesn’t create new audiofiles.
It copies (if this option is checked) the used audiofiles into a new Folder and the reference data is copied into an xml file.
These audiofiles are exact copies of the files that are/were in your pool.
It could however be that the project contains a bunck of files that are/were not located into the “audio” folder of your project. Upon exporting selected tracks, these files will also be copied.
Or your project is set to 32bit float, and the used files are all 16 bit or so …
I suggest you compare the files in the project audio folder with those in the exported media folder, so see whare the differences are to be found.
Fredo