I have downloaded a music video from YouTube and converted it to mp3 format, then transferred it into Audacity for editing before burning to CD. A considerable amount of clipping is being indicated on the playback monitor. Is it possible to use the Audacity editing tool to reduce this clipping? (ie. reduce the sound level of the YouTube download)
Many thanks.
Could you describe that in more detail.
If you just mean that there are a lot of red lines due to “Show Clipping” (see: Audacity Manual) then that may not be worth worrying about. The “Show Clipping” indicators are “warnings” that the waveform has “touched” 0 dB, but if the waveform has “only just touched”, then it may not actually be “damaged” (or not noticeably damaged).
Note that the sound on many YouTube videos is appallingly bad quality and it may not be possible to improve it. If the audio in the original video sounds audibly distorted even when you turn down the playback volume, then it is probably beyond repair.
Thanks for your reply. Yes, I was referring to numerous red lines due to “show clipping” being switched on. As you suggest, there is no noticeable distortion when I listen to it, so I will proceed anyway. I guess I’m a bit of a perfectionist!
Actually, an MP3 can go over 0dB without clipping. It often happens with MP3 encoding. Since MP3 is lossy and the wave shape changes, some peaks get higher and some peaks get lower. The majority of my MP3 collection (ripped from CD) shows clipping when I open it in Audacity.
If you run the Amplify effect and it defaults to a negative dB gain adjustment, that’s telling you how far over 0dB your peaks go.
If it goes over 0dB and you convert it to WAV (16 or 24-bit) it will clip. Your digital-to-analog converter will also clip if you feed it the full-volume (decoded) MP3 that goes over 0dB. But, I’ve never heard of a case where this slight clipping was audible. That is if you hear MP3 compression artifacts, reducing the volume by a couple of dB won’t make the artifacts go away.
I guess I’m a bit of a perfectionist!
You can reduce the level by one or two dB before MP3 encoding if you don’t want the MP3 going over 0dB.
And… YouTube (and almost all streamed audio/video) is lossy-compressed. If you save-as (export to) MP3, you are going through a 2nd generation of lossy compression. The quality loss isn’t always audible, but it’s something to be aware of… especially if you are a perfectionist! 
That is very helpful … Many thanks