Get the rockiest CD you can think of where the music thereon was recorded in, say, the 1970s, and play it. Then get just about any modern pop recording. Which is louder? The latter.
This is not for no reason. Apparently most music purchasers want their CDs to be loud. If they are listening to a set of CDs on a CD jukebox, when one that comes up that seems less loud than its predecessor, they are disappointed. Perceived loudness is a function of average playback level, not peak level.
PCM-based digital recording systems, such as the compact disc, have a hard upper limit to the recording level. You cannot go beyond 0dB. That’s all there is to it. So record producers use limiters and dynamic range compressors to bump up the average level without pushing the peaks into ‘red’ territory. Sure, it damages the fidelity of the music, but that’s the price you pay for popularity.
That’s the theory, anyway. But all too often they use hard limiters, which effectively clip the music just as though an amplifier were being overdriven. The picture here is a small part of the wave from of the song ‘Angels Brought Me Here’ from the debut single CD of the winner of Australian Idol, Guy Sebastian. Look at those waveforms! Chopped right off, top and bottom.
The CD mastering was performed by someone called Oscar Gaona at Studios 301, Sydney.
Pleasing everyone, including those who like their music pure, would be possible. Just can the compression and limiting. All the listener has to do if he or she wants it louder is advance the volume control. Is that too much to ask?