Audacity mp3's add length to saved files!

I made some short two bar loops of sounds, and saved the selected audio files as mp3’s. When I opened each saved loop in Audacity, I couldn’t help but see (and hear) that each file had additional space added on to it! It looks like the unedited file got saved, while the edited file didn’t get saved.

How is it that this happened? Anybody else experience this?

I did save the Project with the separate loop files, which DID open correctly with each file’s loop and edit info intact. But it’s the saving of the individual edited files as MP3’s that didn’t save as what I had edited.

Of course I would love it if Audacity saved loop info but I haven’t figured out if it can do that. (Can it?)

Thanks in advance!


There are two issues here:

  1. MP3 always has a bit of “padding” at the beginning.
    This is an unavoidable limitation of the MP3 format. This is one of the reasons that MP3s are rarely used for loops.
    WAV, AIFF, FLAC and OGG do not have this problem.

  2. You appear to be using an old version of Audacity.
    The current version (Audacity 2.4.2 Audacity ® | Download for Mac OS) is able to compensate for the “padding” in MP3s that are created in Audacity. (Audacity 2.4.2 now supports a special metadata tag that says how much padding has been added during encoding. On import, if that tag is present, Audacity will automatically trim off the padding.)

Thanks much Steve! Great answers! I downloaded 2.4.2 and was able to save the files as .wav, which worked just like you said.

Is there a way for Audacity to save loop info?

Thanks again!



Loop info is often proprietary and specific to one range of products. Probably the most widely supported loop format is Acid Pro (Now owned by Magix - price around $150)