The perception that older CDs are louder than newer ones is primarily due to changes in audio mastering techniques rather than any inherent difference in the format itself.
In the early days of CD production, the loudness war was prevalent. The loudness war refers to a trend in the music industry where recordings are mastered to be as loud as possible, sacrificing dynamic range and causing compression. This was done to make songs stand out and sound more impactful on the radio or in comparison to other tracks.
As a result, older CDs from the late 1980s to the early 2000s often have a higher average volume level throughout the entire duration of the album. However, this excessive loudness came at the expense of the natural dynamics and nuances of the music, leading to a loss of detail and potentially causing listener fatigue.
In recent years, there has been a shift towards more balanced and dynamic mastering techniques. Music producers and engineers now aim for a more open and natural sound, allowing the music to breathe and preserving the original dynamics of the recordings. This change has been driven by a growing awareness of the negative effects of excessive loudness and a desire to improve the overall listening experience.
As a result, newer CDs often exhibit more dynamic range and a more natural sound compared to older CDs. This can give the impression that older CDs are louder because they have a higher average volume level, whereas newer CDs might have quieter sections and more pronounced differences between soft and loud passages.
It's worth noting that the loudness difference between older and newer CDs is not necessarily a characteristic of the CD format itself but rather a consequence of the way the audio is mastered and produced for each release.