I’m running Audacity 2.3.3 on Windows 10 Pro Version 1903.
When I import some MP3 song files into my project, Audacity shows volume levels with various clipping above 0 db. I know this because if I try to use the Amplify effect, I need to enter a negative value to prevent clipping. Before I claim that Audacity is boosting the levels to where some clipping occurs, how can I tell if my ripping software caused this? My ripping software is set to 100% for output volume. Yes, if I lower that, and re-rip then I don’t get the clipping in Audacity but I also can measure if Audacity increased the levels some. So, is there any possibility that Audacity is boosting the volume on import and can that be prevented? Or is there already clipping in many of my ripped MP3 tracks?
Thanks.
Yes but it’s the MP3 compression, not Audacity itself. As you probably know, MP3 is lossy compression which means he wave shape changes. Some peaks get a little higher and some get a little lower. This does not affect the “loudness” or the dynamics. But of course, if you reduce the level to prevent clipping the loudness is reduced.
Some people normalize to -1dB or so before making an MP3.
The file isn’t actually clipped. MP3 can go over 0dB without clipping so Audacity is showing potential clipping. If you play the MP3 at “full digital volume” you will clip your digital-to-analog converter. But as far as I know, that slight clipping is not audible. i.e. If you are hearing compression artifacts, reducing the levels to prevent clipping won’t remove the artifacts.
…Something similar happens with the vinyl cutting and playback process. The higher peaks and higher crest factor lead some people to believe the vinyl is more dynamic (less dynamically compressed) than the digital version. But again, this doesn’t affect the sound of the dynamics.