Exported mp3 files twice as big

I have many mp3 files from a talk radio show I enjoy. Because the volume in each file varies a LOT (Some passages so loud as to be painful), I have compressed each file. I think this has solved the problem but introduced a new one.
I created a macro which simply compresses each file then exports it as a mp3 file. Each of the compressed files is almost exactly twice the size of the original (non compressed) file. Example: a 25,390 KB original compresses and exports to 50,776 KB.
I have checked and the bitrate, length (minutes), and mode (mono) are exactly the same in both versions. A visual comparison of both files looks identical (except for the compression of course).
I know I’m missing something simple but danged if I can figure it out !!!
Any help greatly appreciated.

I have checked and the bitrate,

Check the bitrate again, and maybe check it with [u]MediaInfoOnline[/u].

Bitrate is directly related to file size. kbps is kilo_bits_ per second. There are 8-bits in a byte so you can divide by 8 to get the file size in kilo_bytes_ per second.

(Embedded album artwork adds to file size separate from bitrate but that’s unlikely to apply here.)

Worth noting that if you start with, say, a 128kbps mp3, edit it, & and save it as 128kbps mp3,
the result will sound more like 64kbps mp3.

If you want to maintain the original sound quality, an MP3 editor is the way to go …

I think this has solved the problem but introduced a new one.

This isn’t fun. MP3 compression sound damage is permanent and the best you can do is keep it from getting too much worse.

I used to record “Car Talk” off-air and burn a CD for listening in the car. It was OK, but the FM noises and distortion were pretty annoying. I rejoiced when they offered it on-line. Perfect, crystal clear sound and no FM distortion. However. It turned out that Ray mumbled in his beer and Tommy had a nuclear laugh that could wipe out small cities. Sound familiar? The missing step was the transmitter compressor/limiters. I now had the raw studio feed.

Enter Chris’s Compressor. Chris designed it so he could listen to opera in the car. It is an active compressor that does second-by-second volume management and mimics reliably the broadcast compressors.

I change one value, Compress ratio: from the default 0.5 to a stiffer 0.77 and Car Talk sounds exactly like KPCC Radio but without the FM noise.


After you install it, Select the whole show and Effect > Compress dynamics.

There is one easy to work-around bug. Chris doesn’t like running off the end of the show, so I leave some unwanted trash at the end for Chris to “chew on” and then cut it off after Chris is done.

Burn a CD (perfect quality WAV format) and we’re done.

You have an extra step if you need to walk away with another MP3. There is no relationship between the MP3 going in and the one coming out. Audacity bumps the bit rate up to stupid-high rates internally and forces you to make a whole new MP3 when you get done (no, it doesn’t make the MP3 distortion go away).

When you make your new MP3, you can mess with the compression values…

Screen Shot 2022-01-17 at 1.27.06 AM.png
…to get the file size you want. It’s not going to be 192 as in the illustration. That’s the value for audiobook publication submission. Keep reducing that value until you get the file size you like. As you do that, listen for compression distortion. Honky, talking into a milk jug or wine glass. That will get worse as the file size goes down. You’re stuck with that. You can try reducing the show from stereo, two sound tracks (if that’s what you have), to mono, that will help a lot. You can also try messing with non-constant compression.

That’s the way it is. There is no good way to put the original quality back in an MP3. That’s the MP3 curse.


There is one caution. Pure MP3 editors (MP3 Direct Cut, etc.) typically don’t allow taking the show apart, applying effects, and then putting it back together again. They’re limited to global volume changes, cutting, and simple actions like that.

Read the instructions.

MP3 gets its small, efficient files by re-arranging pitch/tones in the show, and more importantly, leaving some of them out. You can’t reverse that process.


Oh, and Chris isn’t going to fix that bug. He reached end-of-life.