I still remember the first CD I ever heard: a copy of Pink Floyd's The Wall a cousin of mine owned. Specifically, I remember being thrilled by the incredible sound quality. Granted, I had been a cassette devotee, so it was easy to hear the night-and-day difference in sound quality between the two. Like many, I was able to hear aspects of songs I'd never noticed before. To my relatively untrained ears at the time, it sounded like nothing could top the CD, especially not vinyl.
In the years since, thanks in large part to discussions with many an audiophile, I've come to re-embrace the virtues of vinyl. While CDs certainly sound "clean," nothing tops the warmth of a record. This has everything to do with recording techniques. A vinyl LP is recorded in analog, which captures every single sound of the original source, including ambient noises in the room. CDs are recorded digitally, which means the recording equipment breaks down the original source into a series of ones and zeroes, compresses this series by "squeezing out" some of those ones and zeroes, then burns them onto disc. CDs capture all the notes of a piece of music. Records capture these, plus the conditions of the recording.
It's a wonderful thing, then, that DVD-Audio came along.
What is DVD-Audio?
In short, the designers of DVD-Audio took CD recording technology and improved it dramatically. The key improvement is in the "sampling rate." As I mentioned above, when original (analog) source material is converted to a digital format, the recording equipment breaks the music down into bits of information (in the form of ones and zeroes). Sampling rate refers to the number of bits per second that are taken from a continuous source signal. This basically translates into the amount of information that appears on a disc. When this information is burned onto a CD, the elements of the original source that weren't sampled are left out. These are always "extraneous" bits, such as ambient studio noise and resonant frequencies. What's left is clean and sounds great, but something is missing.
A CD records its source material at a sampling rate of 44 kilohertz (kHz) per second. By contrast, a DVD-Audio disc records its source material at a much higher sampling rate: usually 96 or 192 kHz per second. This means exactly what it implies: a DVD-Audio disc reproduces more of the original recording, by quite a significant factor (up to 100 times more). This results in music that's richer and more nuanced. It's not so much that one can hear more music, but more specific details. The dynamics between individual instruments are more easily discerned, and the tone of each instrument is more distinct in relation to the other instruments in the recording. In spatial terms, I'd call DVD-Audio three dimensional, whereas CDs are only two. In the end, DVD-Audio manages to combine the cleanness of a CD with the warmth and depth of vinyl — without all the cracks and pops, of course.
Is this like DVD-Video?
DVD-Audio discs shouldn't be confused with DVD-Video discs. Some DVD-Audio discs might contain video and graphic features, but on the whole, they're used to create compelling audio presentations. Most DVD-Audio discs can deliver discrete 6-channel playback (also known as 5.1 surround sound); this means that 6 speakers, two front, two rear, a center channel, and a subwoofer, receive individual pieces of musical information, independently of each other. Many performers are beginning to find surround sound a desirable format, and its popularity is increasing. But the DVD-Audio format works just as well for stereo recordings.
What about Super Audio CDs?
SACDs offer similar sound quality to DVD-Audio. Different recording techniques are used to create them, but the fundamental principle is the same: thanks to higher sampling rates, SACDs feature more information than standard CDs. There is little agreement as to whether DVD-Audio or SACD provides better sound; it's largely a matter of individual listener preference.
To read more about the differences, read our guide to high-resolution music.
