Problems Converting a MP3 or WAV file from 128 kbps to 64 kbps


I’m having problems converting an audio file (created as an MP3 then exported to WAV) through Audacity and saving it in 64 kbps format, Mono, 8000, U-Log format (for IVR).

For some reason the file retains it in 128 kbps and I can’t figure out out to override that - even though I check the options category and update the bit rate.

Online tutorials confirm that it appears I’m saving/exporting correctly - but so far, I’m unable to generate a workable audio file for the IVR.


  1. Set the “Project Rate” (lower left corner of the main Audacity window) to “8000”.
  2. “File menu > Export > Export Audio”.
  3. Select “Other uncompressed files” as the file type.
  4. Select “WAV (Microsoft)” as the “Header”.
  5. Select “U-Law” as the “Encoding”.
  6. Enter a name for the file, ending in “.wav”, and select the location where you want to save it.
  7. Click the “Save” button.
  8. If the “Metadata Editor” opens, click the “OK” button to complete the export.

The exported file will be “ADPCM, u-law, 8000 Hz sample rate”.
If the track was mono, the exported file will have a bit rate of 64 kbps. If the track was stereo, it will have a bit rate of 128 kbps.

If you need to convert a stereo track to mono, then before you export, use “Tracks menu > Mix > Mix Stereo down to Mono”.

I’d recommend that before exporting, you change it to 64kbps or whatever you’d like.

You’ve clearly not tried that yourself. That will not work. Please check that your advice works before posting so as to avoid misleading other users.

There is one other problem with this idea. When you make an MP3, you get two things: the original show plus compression damage.

When you make a second file, the software is working on the show plus the damage, making it worse. Typically this process doesn’t survive three passes. You may have a sound file at the right bits-per-second, but the show sound quality is likely to be rubbish.

There was a recent show on why Music On Hold (your call is important to us) sounds as bad as it does. Behold, three-passes.

Never do production in MP3.


Thank you all for your recommendations. We will give this a shot!

I thought it meant changing the sample rate… I was thinking of the hz. Sorry