Audio compression, loss of quality importing mp3 and exporting to mp3

[Mess]

Hi,

 

I have a basic question which I am asking due to a disagreement I had recently, if I have 2 audio files at 320 mp3 (2 parts of a show) and I import these 2 audio files into a logic project, join them and export to a 320 mp3 file, would those original 2 files suffer any loss in audio quality as they have been exported again? I'm wondering would there be further compression just because they are being exported again even though the bitrate is the same each time.

 

Thanks

[triplets]

The fact of using mp3s is already a loss of quality.

Try to get the original PCM (wav or aiff) file of the show if possible.

If not, nothing you can do since Logic will convert them to PCM when you import them.

[David Nahmani]

if I have 2 audio files at 320 mp3 (2 parts of a show) and I import these 2 audio files into a logic project, join them and export to a 320 mp3 file, would those original 2 files suffer any loss in audio quality as they have been exported again?

Yes. This type of audio degradation, due to the mp3 decoding and mp3 re-encoding, is called generation loss:

 

[Mess]

Hi thanks for the replies, I understand he mp3 is lower, the end file has to be an mp3 (or similar quality), but I was interested in the 'generation loss' as you say, which I assumed would happen but had wondered how noticeable it was, thanks for the vid which answers the question.

[David Nahmani]

You're welcome!

[stardustmedia]

Depending where the media is played back, importing from proper 320kbps MP3 then exporting again to high quality 320kbps is still good enough. I wouldn't press audio CDs with it, or high definition audio. 

 

The lower the bit rate the more obvious the quality loss.