03-Feb-2016, 18:14
(03-Feb-2016, 17:17)f1eng Wrote: USB and Ethernet have protocols to make sure the data is sent correctly.
...
Unfortunately for us "the data" that is sent correctly is designed for a machine to use and as you point out we're far from machines (or I could fix my computer with a placebo) so the data we hear can differ. The error correction helps computers receive the data sent, but we're still learning a lot about how to send sound digitally so that the human hearing the sound perceives the sound we're trying to transmit.
When the telephone was invented voice data was transmitted, but it took decades of research to learn how to transmit the right data in the right way to make what came out of the telephone sound like the human on the other end. Then we switched to digital, wireless, and our research hasn't caught up so the sound quality has suffered. We're transmitting more exact "data" now but it sounds far worse because we're paying more attention to the computer communications than the human perception.
Digital music is taking a similar path. When music went digital they promised "perfect sound forever". Whoops. It turns out that digitizing music certainly made it error-free from a computer data perspective, which is very useful when manipulating it but many people found that CDs sounded worse than vinyl. CD players improved, and now DACs are making rapid progress. The improvements aren't to the perfect transmission of bits but rather to other things that affect the sound we hear when those bits are transmitted. It turns out that the digital reconstruction filters are critical as is the control of noise even outside the audio band. All cables act as a filter to some degree. Let me assure you that we'd love to have made a perfect optical fiber but while we've made amazing stuff even optical transmission is imperfect. Those darn analog effects keep our digital data from being perfectly transmitted. Our imperfect understanding of what data needs to be transmitted in what ways keeps the sound from being perfect even if we could transmit the bits perfectly.
We keep improving the data transmission technology (Ethernet Cat 5, 5e, 6, 7, etc.) and one can easily build a robust data network now with ethernet, but that doesn't mean that we understand everything about digital music or making what comes through ethernet sound good. USB has even more technical issues with noise and other detractions from perfect transmission of music data. Luckily we're one our way to understanding them, and if you're interested then modern DAC design makes fascinating reading.
