Rbstehno
If you take Jpeg and convert it to compressed TIFF(G3) and uncompress it later you won't get jpeg anymore but much larger file. That's exactly what is happening with MP3.
In order to be compressed into APLL it has to be decompressed first and MP3 format is lost forever. APPL file size will be larger than original MP3 but smaller than one compressed from original recording since MP3 lost part of the data.
Airport Express have no way of knowing what was original format used to convert to APLL. Everything looks the same and only amount of detail is different.
Perhaps you meant that Airport Express decompressed file has amount of data (quality) equivalent to original MP3.
If you take Jpeg and convert it to compressed TIFF(G3) and uncompress it later you won't get jpeg anymore but much larger file. That's exactly what is happening with MP3.
In order to be compressed into APLL it has to be decompressed first and MP3 format is lost forever. APPL file size will be larger than original MP3 but smaller than one compressed from original recording since MP3 lost part of the data.
Airport Express have no way of knowing what was original format used to convert to APLL. Everything looks the same and only amount of detail is different.
Perhaps you meant that Airport Express decompressed file has amount of data (quality) equivalent to original MP3.