Why?

As I write this, it is 2023. If you're just looking to play a popular song, Apple Music and Spotify do the job. But many recordings and masterings I return to often are not available through streaming services.

Notes on CDs

Quality

After about age 12, the human ear can hear sounds only up to 14 kHz at typical listening volumes. That threshold drops with age. CDs are sampled at 44,100 Hz and can reproduce frequencies up to 22.05 kHz. This covers more sound than most people can hear.

Vinyl records can capture more because they are analog, but the extra content is lost on the listener. No matter how much your friend with the $50,000 turntable insists otherwise, the physics of hearing set the limit.

SACDs

So why collect SACDs if quality beyond the CD standard is irrelevant? The answer is simple: it is fun. SACDs often include more than one layer, sometimes three. The first layer is the standard Red Book CD format. It plays in any CD player.

You might ask, Why spend $30 or more for what sounds like a normal CD? The reason is that SACDs are often remastered from the original tapes. A good engineer might remove unnecessary reverb, fix tape dropouts, or clean up the mix. One example is the power cut issue in Black Sabbath's original Writ recording. These adjustments are part of the remastering process.

Other layers might include a 5.1 surround mix, created from the original multi-track tapes. This setup can recreate the feel of a studio or theater, assuming you have the speakers to match. The stereo high-resolution layer offers the least practical benefit. If it uses the same mastering as the CD layer, it sounds the same. If it uses a different mastering, the change may be worth it. In many cases, only the 5.1 mix is new.

Before buying an SACD, check which layers are different. It can save you money and frustration.

Frequency Range

CDs can reproduce frequencies up to 22.05 kHz, but the rest of your equipment must match that range. This includes your amplifier, digital-to-analog converter (DAC), and speakers. Many speakers cut off at 20 kHz or lower. So why invest in media that can go beyond that? For most people, there is no reason.

Loudness

Music is commercial. Mixing is the art of making people enjoy what they hear in the place they hear it.

In the early days of CDs, players were expensive and lived in quiet homes. Engineers could master albums with full dynamic range. This did not last. Soon, people were listening in cars or on the move. Portability brought noise, and CDs began to skip during motion. Early players had limited memory buffers and often failed to keep up.

When you play a CD, it loads audio into memory and uses a DAC to convert it to sound. The DAC operates at its own internal rates and sometimes introduces distortion.

As cars became a popular listening space in the 1990s, engineers had to adjust. The car is a noisy environment. Music needed to be louder to cut through it. Fortunately, the ear likes volume. The result was a louder, more compressed sound. The range shrank, and the middle became thicker. This sounded good in the car, but it weakened clarity for the home listener.

Hardware

When you explore sound recording, you find that you are hearing someone else's judgment. A sound engineer, likely over 40, decided what to keep. The engineer filtered and shaped the recording before it became a digital file.

The product then passed through mastering, was sent to manufacturing plants with varying hardware and materials, and ended up on a disc. Your player adds its own noise, depending on the quality of its cables, tubes, DAC, and amplifier. Your speakers shape the rest. The final sound is close to the original, but not exact.

You will never reach perfection. Do not worship hardware. Listen to the music. That is where the value lies.