How to convert a stereo MP3 to mono MP3



We had an MP3 created for a message greeting on our phone system. It is stereo MP3, not sure what the bit rate is, but is sampled at 44.1k.

Our sound system requires it to be in this format:

  • 16 bit
  • Mono
  • 44.100 kHz

I have Garageband and went out to find Peak but they are out of business. Any ideas on how I might be able to convert my file?

Thank you!

Swisher Sweet

Posted 2014-03-06T12:37:14.950

Reputation: 173

Related -

– AJ Henderson – 2014-03-06T14:21:42.323



  1. Download Audacity here. Also download the LAME MP3 library here
  2. Install Audacity on your system. Install the LAME MP3 library.
  3. Open Audacity
  4. Click on File > Open... and select the mp3 file in question
  5. Click on Track > Stereo track to Mono
  6. Click on File > Export. Choose "MP3 Files" as Format on the dropdown menu and click save.

    • Note 1: If you want to save in higher quality bitrate click on options and select the desired bitrate.
    • Note 2: As you click "Save" on the export menu it might ask you to locate the LAME MP3 Library. Just point it to wherever you have exported the file.



Posted 2014-03-06T12:37:14.950

Reputation: 96


On Linux systems like Ubuntu, you can use ffmpeg:

ffmpeg -i input.mp3 -c:a libmp3lame -q:a 2 -ac 1 output.mp3


  • -c:a libmp3lame: The audio codec to use
  • -q:a 2: The audio quality (bitrate), see LAME Bitrate Overview
  • -ac 1: One audio channel

Martin Thoma

Posted 2014-03-06T12:37:14.950

Reputation: 171

This is a far superior method to using Audacity, especially for those like me who have thousands of files to convert. – Phil Goetz – 2020-02-06T16:10:33.907


There are lots of tools. You can try Foobar2000 (which is a music player but can convert sounds too).


Posted 2014-03-06T12:37:14.950


While I do believe this could be used to accomplish the task, if you could provide a little more details as to how it could be done with that tool, this answer would be far more beneficial. – AJ Henderson – 2014-03-06T14:30:14.857