DVD-Audio vs. SACD vs. CD
As the format war continues we need to take a close look at not only the proâs and cons but what this new marketing push is really all about.
|
Metric |
SACD |
DVD / DVD-A |
CD |
|
Sampling Rate |
2.8224 MHz (64 x 44.1 kHz) |
Up to 192 kHz |
44.1 kHz |
|
Amount of Bits |
1 bit |
16 to 24 bits |
16 bits |
|
Dynamic Range (Maximum) |
104 to 108 dB |
104 to 108 dB |
96 to 98 dB |
|
Copy Protection |
Yes |
Yes |
No; at time of writing |
|
Multi Channel Capability |
Yes |
Yes |
Yes; but with very lossy compression |
|
Brick Wall Digital Filter |
No; analog filter |
Yes |
Yes |
|
Video / Multimedia |
No; audio only |
Yes |
Yes, but limited by storage capability |
Sampling Rates: One of the major arguments against the CD is that the sampling rate is too
low, and a higher sampling rate is needed to extend bandwidth and ease filter slopes.
There is evidence supporting this. How high is enough, however, is still hotly debated.
Amount of Bits: Adding more bits certainly gives more dynamic range and less distortion, but the best D/A converters can realistically only reproduce about 18 - 19 bits of resolution.
This is not about to change unless there is a major paradigm shift in the laws of physics.
Is 24 bits better than 20 bits? Not if all those other bits are lost in noise. SACD uses 1 bit at a very high sampling rate giving it an effective 120 db SNR in the audio band.
Copy Protection: At time of writing the CD has no copy protection, some have been adopted but withdrawn from the market due to major problems. New attempts appear to be made monthly. SACD and DVD-A both have copy protection schemes.