Things That Suck
Initial posting: 2006-10-15
Updated: 2009-07-19 (music clips)
Updated: 2017-09-03 (music clips, changed "CD" to "digital audio")
Updated: 2021-07-12 (wave and audio samples, simplified dynamics processing procedure)
For some unknown reason, CD mastering has become a competition to see how much louder music can be produced without compromising quality. Unfortunately, that threshold has already been reached, and it's rare to find a CD that doesn't have a throbbing component to it because of the way the audio waves are compressed.
Note that in this case, "compression" refers to an amplification process; not the file compression that occurs when you save music in a compressed file format like MP3 or AAC.
Let me show you what I'm talking about. Here is a visual representation and an audio sample of a piece of music produced in the early 1990s.
Sound sample 1: a short mix of Toto's "Rosanna".
Today, if this was "remastered" or re-released in a compilation album, chances are the wave would look and sound something like this:
Sound sample 2: a short mix of Toto's "Rosanna", dynamically compressed.
The problem with this procedure is that you lose valuable sound data as the wave forms are squished and chopped off at the top and bottom ranges. This is what is meant by "compression".
Radio stations have been using dynamic compression for years to make up for the varying levels between songs and advertisements. This is so you don't have to constantly turn the volume up and down.
So why is it acceptable for radio and not CDs? Because you always want to start with a clean audio source and then give the listener the option to process the sound in whatever way they wish. When a CD is dynamically compressed, there is no procedure for converting compressed audio back to its original wide dynamic range.
Here is how audio is compressed.
I started with the soft limit -24 dB preset in Adobe Audition.
Then I added a 24 dB Make-Up Gain to boost the amplitude.
It's as simple as that. The result is the Sound Sample 2.
Here we are in 2021 where talking about CDs doesn't make much sense because they are no longer mainstream. What is mainstream? Music streaming, of course.
Streaming music has its own drawback, but most people who listen to music or watch movies streaming are using portable devices with limited sound quality anyway, so it really doesn't matter anymore. Still, in those occasional where an audio CD is produced, it seems that the audio engineers still love keeping their finger on the wave hammer button.