[url=http://meincmagazine.com/civis/viewtopic.php?p=29523047#p29523047:9awvhu23 said:
redleader[/url]":9awvhu23]
I don't think language is the main issue there, since he talks about time correction, which would only make sense in the temporal sense of jitter, not the offset kind (AFAIK, I'm no expert on CD audio, so correct me if I'm wrong). He also linked an article that is clearly referring to temporal jitter. He may also be combining other types of jitter here, but I don't think thats the main problem, and that kind of points to a more fundamental lack of understanding more so than anything.
I'm not an expert by any means, but my understanding is CD audio is nonindexed data stream, basically a 70 minute long series of bits.
If the rotation speed is faster than those bits are needed, the cache eventually fills and there's no place to toss the bits as they are read. So you stop reading until there is space in the cache, but there's no good way to tell where in the bitstream you ended, since the bits aren't indexed. The drive would sometimes miss, and start reading a little before or a little after where you left off, giving you a tiny jump forward in time or a tiny juamp back.
Jitter correction in CD audio means the drive intentionally resumes earlier in disc time, giving some redundant data that it can use to find where the data stream actually picks up. But it comes at a performance hit, since you're reading the extra data and doing extra processing.
Obviously, as you note, this isn't the jitter described in his linked document.
[url=http://meincmagazine.com/civis/viewtopic.php?p=29522109#p29522109:9awvhu23 said:
Paltivar[/url]":9awvhu23]
Is he wrong on Nyquist? Looks like, AFAICT. But I don't have some special version of what he meant instead of what he said, and language differences will obscure the difference between topics that are very hard even for native speakers.
Yes he is wrong about Nyquist, in at least 5 or 6 different ways, but forget all that theory and complexity. You don't need to understand sampling to know that CD audio does just fine above 10 kHz. Just listen to CD audio! You can hear with your own ears even if you speak Swahili and every text ever written is in Danish! Hell I knew that long before I ever picked up a textbook from playing with my parents stereo's EQ knobs when I was like 10. The 14 kHz band sounded fine. Anyone who has ever done room correction or EQed headphones will know this. There is nothing necessarily theoretical about this, simple experience will teach you just as well.
Anyway, I also dislike the implication that you need to speak the Queen's English to know about audio. I've worked with Chinese audio designers who didn't speak a word of English, but still designed perfectly competent products. The vast majority of the niche stuff sold to HeadFi readers these days is designed by people who don't speak English. I don't hear them complaining.
Why do you assume he's an designer, as opposed to a user? He said he was in music production, he almost certainly doesn't have the signal processing engineering background. But thats as valid of place from which to form a viewpoint as a designer.
There was never an implication that you needed English to be competent, if anything I've been arguing for the opposite. What you do need English for is to explain your viewpoint on nuanced issues to an English speaking audience in an English language web forum.
I'm not going to defend his views on Nyquist or jitter, so you don't need to reiterate why you think he's wrong to me. I'm personally not clear enough on what he's trying to say for me say he understands the issue, and the charitable position for me to take is to attribute that to communications rather than incompetence.