You have experienced this during your own listening:
Music released today typically has a dynamic range only a fourth to an eighth as wide as that of the 1990s. That means if you play a newly released CD right after one that’s 15 years old, leaving the volume knob untouched, the new one is likely to sound four to eight times as loud.
As Ethan Smith has written, the problem is with us all over the place:
Over the years, rock and pop artists have increasingly sought to make their recordings sound louder to stand out on the radio, jukeboxes and, especially, iPods.
But audiophiles, recording professionals and some ordinary fans say the extra sonic wallop comes at a steep price. To make recorded music seem louder, engineers must reduce the “dynamic range,” minimizing the difference between the soft and loud parts and creating a tidal wave of aural blandness.
“When there’s no quiet, there can be no loud,” said Matt Mayfield, a Minnesota electronic-music teacher, in a YouTube video that sketched out the battle lines of the loudness war. A recording’s dynamic range can be measured by calculating the variation between its average sound level and its maximum, and can be visually expressed through wave forms. Louder recordings, with higher average sound levels, leave less room for such variation than quieter ones.
The problem even extends to vinyl releases, as Angry Metal Guy chronicles:
Labels are also looking to cash in on vinyl’s new found popularity, and so there’s plenty of lazily produced, poor sounding special edition reissues out there. And even with new vinyl, there’s never a guarantee of a dedicated, dynamic master, only the possibility. If the vinyl is sourced from the CD, it will sound every bit as bad.
In short, the problem here is that the ability to turn the music up to 11 should reside with the listener, not the mastering engineer:
There is a major difference between manipulating the recorded volume versus the playback one. When a mastering engineer artificially pushes the volume higher by applying massive amounts of DRC, he or she is changing the recorded volume by squashing the high and low ends of the frequency spectrum. This process has the nasty byproduct of causing transients and imaging to substantially degrade, making the music sound lifeless and dull.

The are many reasons why this huge problem persists today.
But one of the big myths (“metal should go to 11”) can be debunked quantitatively:
One of the most pervasive myths in metal production today is that because metal is supposed to be played loud, it has to be recorded loud. This could not be further from the truth. Some of the most popular metal albums in history are also some of the most dynamic. Master of Puppets: DR12. Rust In Peace: DR13. Painkiller: DR11. Reign In Blood: D14. Notice anything similar about these albums? They were all released prior to 1992, which is roughly the start of the Loudness War. From that year onward, the entire music industry began to engage in constant one-upmanship. Not only did every new album have to be louder than the one that preceded it, but louder than the other guy’s new album as well. By the late ‘90s everyone began to settle around DR6, which is where we are now. Why DR6? Because that’s as loud as you can possibly go while still attempting to hold on to some semblance of fidelity. DR6 is far from ideal, but for every point of dynamic range lost below that mark, you begin to do exponentially more damage to the sound.
A big problem with the industry today is that if you’re on a major label, chances are they won’t let you release an album with high levels of dynamics even if you wanted too. If you send them a fully dynamic master, they’ll think there’s something wrong with it and hire an engineer to smash it down to DR6 before sending it off to the CD pressing plant. …
The truth is that most bands simply have no idea that the DR5 and DR6 masters used on the vast majority of new CD releases are not something people actually want. I know that it’s going to be a long and uphill battle to change the minds of the executives at the major labels, but most bands on small labels generally have a fair amount of creative freedom in terms of what they can do with their masters. So if enough of you let them know that you want them to release albums with proper dynamics, they will listen.
Prog should definitely lead the way out of this morass. Why shouldn’t every self-respecting prog artist proudly and prominently place a DR number on the back of every CD they produce? It could be a way of self-identifying yourself as a serious prog artist committed to only the best sonic experience.
If not, maybe the DR Database needs to be in every reviewer’s toolkit. But keep in mind this caveat that the Dynamic Range number is just the beginning of a discussion about an artist’s musical release, and not the final word on its evaluation:
DR6 is now the industry average and already considered by most sane engineers as too compressed. The recommended level by most industry experts is DR8 or higher. A bit of a fair warning though, a higher number doesn’t necessarily mean its sounds better, but in the overwhelming majority of cases, it usually does. And applying DRC is not evil in itself either, provided it’s done judiciously. The fact is DRC is an invaluable tool that can make a good sounding record sound great. I highly encourage you to read some of our in-depth articles about dynamic range and why it’s not about the numbers, but about the sound.
So I’m sure you’re wondering though, why sacrifice the music’s fidelity just to make it sound artificially loud?
It stems from the fact that at least initially, our ears perceive louder as sounding better, and labels and artists try to leverage that fact in order to gain market share. The idea is simple, if a label’s roster sounds louder than its competitor, you, the listener, will tend to gravitate toward that label’s louder tracks than the other guy’s softer ones.
Perhaps the Priests of the Temples of Syrinx were objecting to the acoustic guitar because of its magnificent dynamic range.
Attention all planets of the Prog Federation: DR6 has assumed control…
