new user - editing MP3 files

[dfehrenbach]

I'm very new to Audacity. What I want to do is to "improve" some mp3 music files. The song as recorded ends very abruptly. I want to increase the length of the song with a few second of silence. How do I "add" time to the tracks?

[kozikowski]

The first thing you need to know is Audacity doesn't edit MP3. Audacity imports MP3 music and converts it to its own high-quality internal format. Then you can edit or apply filters as you need. The music doesn't get any better, it just makes filters more efficient.

The problem comes when you want to create an MP3 with the corrections. Audacity will make you Export As MP3 and create a whole new music file -- not an edit of the old one. MP3 damage adds up every time you make one and the corrected music will sound worse than the one you started with.

There are editors that will perform simple edits directly on MP3s without taking them apart. Those may be useful.

If you want to do it in Audacity, Open the song > End > Generate > Silence > Enter.

That will make too much silence, so you select and cut off the pieces you don't need. Export As MP3. You will also need the "lame" software package to do this job. Audacity will not Export an MP3 by itself.

http://audacityteam.org/help/faq?s=inst ... m=lame-mp3
http://audacityteam.org/download/
(Drill down past the Audacity download...)

Koz

[dfehrenbach]

Thanks very much for your help. The Generate...Silence command on the version I used allows you to enter the length of silence you want to generate, so I entered 3 seconds, exported to MP3 and I was done. Couldn't have been easier!
I also have a few mp3 files that were recorded at a very low volume and iTunes volume adjustment set to +100% on the Show Info/Options panel does not quite make it loud enough. I tried boosting the gain a bit in Audacity but found it added too much distortion. Is this something that could be corrected by one of the mp3 editors you mentioned. Do you have a suggestion as to which editor you found useful for a beginner?

[steve]

I tried boosting the gain a bit in Audacity but found it added too much distortion.

If you use the default settings in the Amplify effect it will amplify as much as possible without distorting, however there are two potential pitfalls:
1) If the original file already had distortion, by making the track louder the distortion may become more obvious.
2) When a file is encoded to MP3 format, peaks in the original that were at 0dB may become distorted during the encoding process.

You can't really do anything about the first problem if it occurs, but the second problem can be avoided by only amplifying to -1 dB (which is very nearly as loud as 0 dB, but it won't distort when encoded back to MP3.

There is a third issue that you are probably already aware of - MP3 is a "lossy" compression format - each time that the audio is compressed to MP3 the sound quality deteriorates a bit more.