Mastering engineer Ian Shepherd, founder of the Production Advice blog, has put in a sterling effort over the last few weeks organising “Dynamic Range Day” to try raise the issues surrounding the “loudness wars”.

If you’re not familiar with the “loudness wars”, go compare a modern CD with one from the late 80s or early 90s. You’ll almost certainly notice that the earlier CDs are quieter. To get the two to play at similar levels you need to adjust the volume knob on your stereo. The problem actually stems back further than CDs to the vinyl era and was a result of bands wanting there songs to be the loudest on jukeboxes. But for various technical reasons the vinyl medium limited how loud you could push tracks, which kept things within reason. CDs too have a technical limit; 0dBFS, but there is no technical reason why you can’t stay at or very near to 0dBFS for the entire length of the CD.

To the layman it might seem that making a CD louder is a good thing, but what you need to understand is that even the early CDs frequently reached 0dBFS for short periods in a track. What has changed isn’t the loudest point on the CD, it’s the average volume across the whole CD, and the frequency at which the maximum volume is reached. To make a CD louder you don’t just record it louder - that would risk going above the 0dBFS level resulting in distortion, instead you compress the dynamic range by making the loud bits quieter (no really!). Because your loudest bits no longer reach the maximum physical limit you can now raise the overall level to make up for what you’ve lost. In effect you’re making the quiet bits louder.

This process is known as compression and it’s a trick engineers use all the time. We put compression on individual instruments in the mix, we put more compression across certain groups of instruments in the mix and then the mastering engineer frequently adds even more across the whole stereo mix. In moderation compression is a wonderful thing. But add too much and the sounds will begin to distort. Another problem is that the noise floor, which was nice and quiet originally also gets raised with the other quiet parts. The net result of this is that the final mastered recording sounds far worse than it should. However, not only does it suffer from these problems, the recording also lacks any emotional depth associated with dynamic release. It’s the equivalent of someone shouting at you all the time, it soon loses its meaning. Imagine being on a loud factory floor and having someone shout “boo” at you. You’d be so used to the noise-level that you’d probably not even flinch. Now imagine being on a quiet stroll through a country park and the same thing happening. The dynamic difference of someone shouting “boo” in peaceful surroundings will certainly catch your attention. A good musician knows this too, and will use it to instil the music with  passion.

There are hundreds of examples of albums that have been ruined by too much compression during mastering. Death Magnetic by Metallica is a famous example, and anything from Californication onwards by the Red Hot Chili Peppers. That said, it’s not happening all over the industry and many mastering engineers – the very people many hold responsible for the problem – are fighting back. They don’t want to ruin music, they want to make it as good as it can be, but they’re being pushed by managers, A&R men and other hangers-on who don’t care about the art. But the mastering engineers can’t fight alone. They have to earn a living giving the client what they want and if the client wants it loud that’s what they have to do. So they need your help. If you’re in a band be aware that loudness isn’t everything, give the music room to breathe and your loud bits will hit with more punch. And if you’re just a listener get involved in Dynamic Range Day tomorrow (March 20th); shout on Twitter, FaceBook, Google Buzz or down at the pub to bring awareness of the issue to more people. But most of all, keep buying good music, the economic argument is one that even the managers and A&R men will listen to.