http://georgegraham.com/compress.html
A plea from a recording engineer not to SQUASH your tracks!
This is just as relevant as we are well and truly within the MP3 age. There is no reason os over-compress your music.
Now, with the CD, we have more than 90 db of dynamic range to utilize, and no surface noise or risk of groove skip to worry about. So what has become of all that wonderful dynamic range? The loudness wars have come back. While most classical CDs still make use of the CD’s dynamic range potential, once again the fallacious belief that “louder is better” has permeated the record industry.
One would think with the ability of the CD to deliver an accurate representation of the master tape, that mastering engineers would become an endangered species. However the skills of mastering engineers can be invaluable in taking a master that might consist of different songs recorded in different studios putting them together into a sonically consistent continuum. Also, experienced mastering engineers can “tweak” masters tapes to improve the sound to play well in a variety of listening situations.
Where the current pressure is coming from is unclear, but several prominent mastering engineers have complained that they are being pushed to make the CDs they work on as loud as possible. The digital audio medium also has its maximum upper limit in level, in this case all digital “ones.” So to make the music sounder louder more of the time, that means adding compression, just like the bad old days of 45s.
My CD player has a digital level display, and I am also able to take the digital output of a CD and run it into a computer editing system allowing statistical study of audio levels, and I am constantly appalled at how many CDs spent most of their time in the top 3-4 db of the 90 db available, with absolute digital maximum level being reached very frequently — sometimes on every beat. Sophisticated digital compressors alleviate the all the horrible distortion that would normally happen from hitting the digital “brick wall,” but nuances and the “airy” quality of the recording are murdered.
In the audio business, there is something of a chasm between broadcast audio engineers and recording engineers. Folks from one camp don’t seem to know a lot about the practices and mindset of the other. I guess I’m lucky to work on both sides of the fence — making music recordings for broadcast and then hearing just how they sound on the air. Every broadcast station already uses compression on the air. There is a legal limit, as regulated and monitored by the FCC, to the loudness of sound on the air. So to keep a signal loud enough not to be lost in fading, and static, compression, which varies by station and format, is inevitably used.
The fallacy that seems to have become pervasive among many people in the pop music recording field, especially among record companies, is that if a CD is pushing the absolute digital max it will somehow be louder or better on the air and presumably win more airplay, and thus sell more copies to the public. This is not true at all. Compressing a CD will contribute to on-air loudness almost unnoticeably. Radio people have the brains to turn up a CD that’s recorded at a normal level, and broadcast stations’ existing compressors will even everything out anyway. The only thing that is accomplished is messing up the dynamic range for those who pay their good money for CDs, “squashing” the life out of any acoustic instruments in the mix, and increasing listener fatigue.
Computer amok graphic Lately, this has been made worse by the increasing availablity of “desktop audio,” which puts powerful compression tools in the realm of the home studio, by using a computer to perform the mastering function. Increasing numbers of CDs are being released that have come from home and “project” studios, with generally less-experienced people doing the mixing and mastering in these settings. So some serious damage is being done by people impressed by how much louder they can make their recording sound by crushing the dynamic range with relatively inexpensive software.
Further, there is the phenomenon of “cascaded compression.” When an already-compressed signal (e.g. a CD) is itself compressed (e.g. when played on a radio station), the compressors can actually “fight” each other, one bringing down the signal, followed by another one with different characteristics that might want to bring it back up at a slightly different rate. The result can border on distortion, and gives an especially annoying “pumping” sound, that ruins what is left of the dynamics of the music and can leave the artist and producer’s sonic intent in shambles. And this is exactly the situation when a compressed CD is run on a radio station with its own compression.
Twenty five years of recording music for broadcast has led me to what seems like a heretical opinion these days: relatively uncompressed music recordings sound better on the air, and no less loud.
The CDs I mix try to preserve as much dynamic range as their genre calls for. And experience has shown that they will stand up to anything else, in terms of loudness on the air.
So in my own small way, I’ll add my voice to those in the professional audio business who are starting to complain about this sonic cheapening of music. With 20-bit bit-mapping technologies and ultimately the 24-bit potential of the DVD medium, the future dynamic range potential of CD is very bright. Why then, is the record business throwing away 95% of the potential of even today’s 16-bit technology in the loudness fallacy?
So in the hope someone takes notice, I’ll continue to complain whenever good music on CD is degraded by excessive compression
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