The MP3 codec is often regarded as the spawn of Satan by audiophiles. For me it was always something that was a product of logic. It began out of necessity, to transfer audio over the web at a time when broadband was not yet prevalent. Then, it allowed music collections to fit on to the less than spacious drives of portable media players.
There is now a generation who have consumed music almost entirely in MP3 format
After viewing a talk by Bob Katz on modern mastering in which he played the detritus left over by the MP3 codec, I was curious enough to have a listen for myself on a number of sources. Using four examples, from Classical to Modern Pop, it becomes obvious how modern mastering process affects digital compression.
'Blue Danube' suffers little from the process, due to the gentle mastering that it would have received. It is preferred with Classical pieces such as this to leave the dynamics generally unaltered.
'Never Going Back Again' and 'Sunday Morning', both tracks from the pre-loudness war era, don't suffer too badly; but there is definite distortion and aliasing in the top end.
Finally, you can hear for yourself the trainwreck that is 'Telephone', crushed and brickwall limited to compete with the loudness levels of the charts.
**Audio has been deleted since**