I have been using older versions of Audacity for several years. I just do simple clean up on songs, to improve my collection, and prep songs for an CDs I might want to burn.

The last version of Audacity I had came with Linux Mint 17.3 Mate. The Version I have now is 2.1.2, with Linux Mint 18.3 Mate.

I have discovered a difference in the Dynamic Compression effect between the two that has me wondering what exactly is happening. In the older version, when I used Dynamic Compression, and exported the song, the song file decreased in size, as if compressed, from it’s imported version. That seemed logical to me. However, in the 2.1.2 version the songs are more than doubling in file size (original 2.3 mb, exported 6 mb). This has me confused, and wondering why it has changed so drastically from the earlier version. I thought I understood what compressing the file meant, but I may not understand what it does after all.

I realize that this is a newbie type problem, but can someone please explain what Dynamic Compression actually does, and why the two versions are some diverse?

I all other ways, 2.1.2 is far more stable than the version I ran on Mint 17.3.

what Dynamic Compression actually does,

The simple version is a program that affects quiet sections of the show different from loud ones.

That’s different from file size, however. Loudness doesn’t affect file size.

You can get that kind of file size difference if you edited a compressed, lesser-quality MP3 file but made a perfect quality WAV file when you were done. Two-to-one or three-to-one size differences are not unusual if you do that.

Dynamic compression is a college course. The original compressor (if that’s what you’re talking about) was restricted useful because it had a defined range. If your show was the wrong volume when you started, it was the wrong volume when you got done—and sometimes didn’t change at all. I had tools you had to run before you ever started to use Compressor.

I like Chris’s Compressor because you can shovel floor-sweepings into it and it will come out the right volume. It had no assumptions.

So you need to sort the file types you are using.


Well, admittedly, I usually start out with an mp3 file, as that is the most common found on-line when buying a particular song. I like to have all my music files in the ogg vorbis format, which is one of the things for which I use Audacity. I’m not a professional recording-mixing artist, I only use Audacity to tweek my music files. I try not to make changes that are too invasive of the original. It seemed to me with the older version I could Normalize an imported song, and then if it was fairly well balanced in treble and bass, I could use Compressor to bring the piece to about the same sound balance (at least by the graph), as I’ve noticed modern songs are from the start. Does that make any sense? I admit I have no formal training in the use of software like Audacity, but figured that since it’s an open source software that I might learn by experimentation.

Did you try Chris’s Compressor? Chris designed it so he could listen to wildly changing volume opera in a noisy car. I use it at a stiff correction setting for a favorite spoken word podcast that has no controls at all, but it may be perfect for you at its default setting.

Most of the volume setting tools start the day with the wrong assumption. They work on volume peaks and momentary loud events. That has only limited presentation usefulness, but it’s insanely easy to program. Much more difficult is perception and loudness. That’s not simple maths any more, now you have to model your ear.

That’s what Chris does.

You can also use the combination of RMS Normalize (a new tool from Steve) and Effect > Limiter. That’s 2/3 of the tools used to tame audiobook readings.

Used in this case at default -18dB and Limiter to -1dB or -2dB. Limiter -3.5dB is the audiobook standard which stiffer than you probably need.


Post back with your experiences with these tools. We use your comments to help other posters. It’s a Forum, not Help Desk.


Okay. Thanks.