Using Audacity to decrease the volume on an MP3

Mac OS Mohave 10.14.2
Audacity 2.3.0

I have a playlist in iTunes that, when I play it, necessitates adjusting the volume up and down as it moves track to track. Some of the MP3 files were seemingly recorded at such a louder volume that they blast me when they play, and I have to rush to turn down the volume.

Can I decrease the general volume level of these tracks using Audacity?

I tried using the Normalize effect, but even going to -3 dB and then re-exporting to MP3 and importing this into iTunes produced no noticeable difference.

What I tried was selecting both tracks (the file is in stereo) and then going to Effects > Normalize > Normalize peak amplitude to…
I didn’t save this project, I simply went directly to File > Export > Export as MP3.

Am I doing something wrong in the process or can Normalize not achieve what I am looking for?

Further research has led me to several possible options:

  • Simply using the Gain slider. I think this is meant more for making one track louder or softer than the other, but I think selecting both tracks before using it would enable me to increase or decrease the volume of the whole file.


  • Using Effect > Amplify and inputting a negative number.


  • Using Effect > Equalization perhaps.


  • And finally, using a different program altogether. This 2013 forum post https://forum.audacityteam.org/t/how-to-decrease-volume-of-a-music-file/28979/1 mentions a program called MP3Gain, which might make it easier to make the volume of all tracks in a playlist similar. MP3Gain does have a Mac version http://projects.sappharad.com/mp3gain/. It would be wonderful just to do this at the push of a button without importing or exporting, although I do worry a bit about downloading programs I’m not familiar with.

Yes you could do that. As in your second post, you can use the Amplify effect with a negative amplification amount to make the loud tracks quieter.

Alternatively, (and probably the best way), you could use a feature in iTunes that automatically adjusts the playback level. The feature is called “Sound Check”. See: iTunes - Official Apple Support

(Sound Check is Apple’s version of ReplayGain, which is what MP3Gain uses.)

Thank you. I had no idea iTunes had such a feature, and none of my internet searches led me to that! I will give it a try.

A follow-up:

iTunes Sound Check didn’t resolve my problem, unfortunately. Apple’s help page on it isn’t super-clear (https://support.apple.com/en-gb/HT201724), but I think it only adjusts tracks upward in volume, not downward, which in my case decreased its effectiveness. It only adjusts up a certain amount, using “the built-in limiter in iTunes to protect against clipping”.

I still found the difference in volume between tracks overwhelming. Whatever adjustment it did didn’t make much of a difference.

Playing around, I found another solution:

  • In iTunes, navigate to the playlist where the tracks are found.

  • Make sure you are in your Library > All Playlists, not in the playlist section of any connected devices. Easiest to disconnect devices first, so that you won’t get confused.

  • Click on the three dots next to each individual track you want to adjust the volume on and select Song Info.


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  • Go to the Options tab and play with the volume adjust slider until you achieve the effect you want.


    2019-02-21_17-37-20.png

  • Click OK, plug in your device, and then sync it.

I had to take the volume of the louder tracks down three notches to make them equal to the volume of the quieter tracks, but it worked.

(I realize this is not an Apple forum, but I just in case someone else tries to do this in the future.)