Exporting to MP3 ruins project

The WAV file looks like this and sounds fine:
wav.png
The extracted MP3 looks like this and sounds almost humorously bad:
mp3.png
Bit rate is “preset”, Quality is set to 320kbps (I also tried 220-60), and variable speed is set to “standard” (I also tried “fast”). My OS is Windows 10, my version of Audacity is 2.1.2, and I’m using LAME v3.99.3. I’ve tried re-downloading LAME to no avail.

What’s going on?? How can I fix this?? Thanks!

Nothing leaps out at me. Is the show music? Where did it come from? iTunes paid music? YouTube Captures? Ripped CDs? Live Captures at Church or Concert? Studio Recordings?

As a temporary experiment: Select the existing good track by clicking just above MUTE. Tracks > Stereo Track to Mono. What happens? Do you just get a slightly flat sounding mono version of the show, or does it turn to weird, low-level trash?

Edit > UNDO.

Koz

And just to be clear… You exported to WAV and MP3, and this is what you get when you re-open both files in Audacity?

I bet Lame doesn’t like out of phase music very much.

Koz

LAME does fine with out-of-phase music…

I just did a quick experiment by inverting one channel of a dual-mono file (so a mono mix gives you silence). I tried regular stereo and joint stereo and they both worked.

In the Stereo mode, LAME encodes the left & right channels independently.

With Joint Stereo LAME automatically switches between M/S and L/R for maximum efficiency. In this case the M channel would be silent (taking almost no space in the compressed MP3 file), and the whole file would be encoded in the S channel. (And of course during decoding, the file is converted back to L/R.)

Cool. So what’s the original problem?
Koz

@Mautlan
You stumped the band.

There’s no reason for a Lame export to do that.

Have you tried a hard Win10 reset?

Koz

Try exporting a short section (about 6 seconds) of that file in WAV format.
Then close and restart Audacity and import that WAV file into a new project.

Does that work correctly?

If it does, try exporting from the new project in MP3 format.

Do you still have the original problem?

If you do, please post both the 6 second WAV file and the 6 second MP3 file to the forum.