What is normalizing?
Due to volume differences
between audio tracks, normalization allows you to set the volume consistent
between tracks during the encoding or burning process. The process usually
used to achieve this is peak normalization. In this process, the level
of each track is adjusted so that the loudest moment (technically the
largest sample value) is adjusted to peak at the largest allowed value
by turning up the gain the required amount. Unfortunately it does not
work well. But there is a solution to this problem, read on.
Can I normalize MP3 files
(make them play at a standard volume)?
Yes you can! However, most programs do NOT do this properly. Those
programs use peak normalization which is a bad indicator of the overall
volume of an mp3.
Also, what they generally do is decode the file back to WAV, normalize
the WAV, then re-encode it to mp3. And this results in a significant
loss of sound quality. Even if some software claim no loss of quality
when normalizing, they are just lying. Make no mistake, you're still
decoding and re-encoding when you do this, and you will lose some quality
each time to re-save a changed file in MP3 format, and hence re-encode
What is the best way to normalize
best way to normalize your mp3s is to use a free software
MP3Gain automatically adjusts mp3s so that they all have the same volume.
But MP3Gain does not decode and re-encode the mp3 to change its volume
(this is good). You can change the volume as many times as you want,
and the mp3 will sound just as good (or just as bad!) as it did before
you started. Mp3Gain uses a special algorithm to calculate how loud
the file actually sounds to a human's ears and writes a tag corresponding
to the decibel value in the mp3.
That tag will be read by any mp3 player that you play the file with.
Let Mp3Gain analyze your whole mp3 library and all your songs will sound
the same volume! But if for some reason, you want the volume back to
its original value, Mp3Gain can remove the tag for you and the volume
will be just as before.
Recommend decibel value to use is 89 decibels (default value).