Suppose I have a FLAC music file and I convert it to let’s say 192 kbps mp3 and then I use this 192 kbps file as a base and create another conversion to 160 kbps.
Not supose I take the source Flac file again and convert directly to 160 kbps.
Do both 160 kbps files have the same quality?
No.
You can test this for yourself.
What you will get is a file that contains only the differences between these two MP3 files and nothing more. If there’s any difference you can either see it (check Spectrogram) or hear it. If the files are 100% identical this exported WAV file will be 100% empty.
Hope that made sense.