Doing this right? import/export question

(using Windows 10 and Audacity 2.4.2)

I am finishing up making a commercial demo reel in which I am importing a mp3 music track to mix with my voice track. I think I read that importing a wav file is better, since the sound quality is affected the more times a mp3 file is imported/exported. However, most of the music, that I was wanting to use, is in mp3 format. Feedback about my process and the possible effect on sound quality is appreciated!

Here was my process:

  1. created a voice track (edited and mastered it, also exported as a wav file)
  2. imported a mp3 music track
  3. mixed the stereo music track down to a mono track
  4. mixed and rendered the voice track and music track (I actually think maybe I don’t need to do this step)
  5. export as a wav file (so that if I need to rework something I can import this file- maybe better to just import my voice wav file and start over)
  6. export as a mp3 to use as my demo

Does this process sound about right? I’m concerned that importing the music as a mp3 and then exporting, both as a wav and a mp3, after I mix it with my voice track is going to mess with the sound quality or distort the music. Is it okay to be using mp3 music files or should I only be importing wav music files?

Thanks, Sue

If you’re stuck with MP3 originals you’re stuck with MP3 originals. And if you need MP3 as your final format the best you can do is 2-generations of MP3.

Any intermediate or temporary files can be saved losslessly as WAV or as an Audacity project. But if you make an Audacity project, also back-up as WAV because a project has many small files and WAV files are more robust.

Damage does accumulate but you may not actually hear any quality loss after 2 generations. Make sure to export at bitrate at least as high as the original.

Thanks for the feedback! Glad to know that a 2nd gen mp3 doesn’t diminish much in sound quality… makes me feel better about importing that format, if that’s my only choice. Also, thanks for the tip about matching the bit rate.