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John Dyson

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About John Dyson

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  1. I don't think that most people argue that when (AS AN EXAMPLE): there is a recording that has signal at up to maybe 40kHz -- that the signal isn't there. It is more that there can be interpretations if the signal is useful... Sometimes a signal can be coherent from some other signal device, sometimes a signal can be an IMD splat from an NR system, sometimes the signal can actually be audio from a microphone. Secondarily, there are issues about the actual quality or useful signal level of the 40kHz signal, and most importantly -- can anyone detect that signal as directly being a part of 'music'. The discussions are more fine than a simple disagreement about specific facts. One problem with these discussions happens because it can be a little tricky to separate out the aspects of the discussion and not confuse them. Depending on agenda, the 'facts' can be somewhat convincingly interpreted in different ways. Organizing the facts in a discussion can be tricky, and there seem to be a lot of traps and pitfalls when there are so many different weightings of the importance of the facts, let alone judging whether or not that the facts are accurate. This problem associated with organizing the facts, understanding the ramifications, weighting the importance ALONG with the emotional aspects conceptually reminds me of 'herding cats'. John
  2. Your patent comment really hits home with me. The Sony DolbyA patent is a near perfect example of a CYA patent. I believe that it is possible that it is maintained simply to benefit from someone else's completion of the project. They patented a key part of an obvious DolbyA implementation (making the feedback straightforward parametric instead of the impossible-in-DSP-land audio feedback scheme as in DolbyA HW.) Even though their patent is worse than inadequate to implement a DolbyA (the most important characteristics of DolbyA are ignored), they thought that they could cause almost any good implementation to infringe, therefore benefit from someone else's work. Some of the 'facts' as stated in the patent are simply 100% wrong, yet enough is accurate that it is likely to convince a judge about the relevence of the patent. Patents like that suck -- I dont even think that it is possible to make a DolbyA decoder sound good even using the architecture in the patent -- but it sure *LOOKS* good. (US 5,907,623). The current expiration is 'fee related', but I'd suspect that they could resurrect it pretty quickly. Also, there are patents like US6807278, which are similar, but my project doesn't infringe that at all either!!! If starting with a technique similar to the way that the patents describe, a developer would be very susceptable to lock-in. Luckily, for my own sanity, I purposefully forgot the Sony patents, and implemented using a VERY foreign technque that supports greater flexibility. Patents aren't evil, but they can cause problems (and benefit holders of essentially garbage patents.) John
  3. Even trying to correct a easily technically provable error is sometimes not easy or helpful unless it is possible to relate to common sense and day-to-day usage. *I believe that pushing the facts about every little misunderstanding isn't a good thing... When there IS an ongoing discussion, an actual bit of technical accuracy CAN be helpful -- I hope 🙂. I wish more people with actual knowledge were more easily accessible. Better access to experts in specific fields could have been incredibly helpful for some of my recent misconceptions, but information is sometimes difficult to find. Some issues, like MQA, bother/worry me personally because I want to maintain my own access to good quality, unmolested, non-DRM music. I also worry about the rest of the world -- working effectively full time for years to learn enough about a specific field that will help 'OLD' (1960s through 1990s) music quality/availability in the future. There IS altruism in the world, and I know of maybe 2 or 3 people working very hard, and others contributing from time-to-time in the somewhat altruistic effort. (Common participants to this forum and some fairly well known professional names have helped the effort.) My own project is NOT limited to (for example) DolbyA at all, and requires resurrecting a lot of difficult to find long-lost common knowledge (and also some hidden know-how.) I have been a big-time victim of misconception -- much of it due to my own resolvable limitations. It has taken a LONG time to get some kinds of accurate information. Can you 'save' people from totally misguided ideas? My answer is -- maybe, if the idea is important enough, but otherwise it is best just to let-go of any kind of 'crusade' (no religious intent for the usage) to correct everything. This is a hobby for most people -- a little bit of misunderstanding is perfectly fine :-). Frankly, I wish MORE people who can contribute actual technical facts could find a way (and the time) to discuss things without being perceived as being know-it-alls or stir controversy. Gaining access to real information, beyond what is currently available, has been troublesome in my current project. Some actual experts DO demure. Maybe the most difficult problem for those of us who don' t know everything -- trying to find people who understand their own limitations, and who TRY to avoid passing on their own possible misconceptions. Audio/recording/etc can be very technical -- and there sometimes might be a tension between the artistic temperament and the kind of knowledge needed to truly understand what is going on. I guess - most important -- remember the goal. Participating in the hobby can required a very different mindset than the technical knowledge needed to implement the tools of the hobby. It is easy to wrongly assume that 'understanding the use' is the same as 'understanding the supporting technology'. They are NOT the same things. John
  4. I truly don't believe that there are fully reliable authorities in almost any field. All too often, there are financial interests, personal interests or opinon/feeling that overrides rationality (lock-in to erroneous technical opinion.) Sometimes, even if a person knows the actual facts, they end up demuring because of overly strong dissenting opinions -- often because of the error sources that I mentioned above. Even when I truly, 100% know a technical answer, I will sometimes demure (not in the right mood to deal with controversy.) Even in areas where I am truly an expert, I make errors, from time to time have erroneous opinions (because not having a current interest/forgetting details,etc.) Lock-in is a problem that all technical people tend to have. Even technical people can be led astray by other technical people. I think that the biggest problems are financial interest or personal bias coming from misguided technical reasoning. Here is an example: I worked with a guy who was a pioneer in a certain field, he was far senior to me -- but he kept advocating using a really error prone source for an electrical delay (synthesizing the RAS/CAS delay for first generation dynamic ram) -- he actually advocated using a series resistor, depending on input capacitance and threshold for CMOS gate -- this RAS/CAS delay had a rather precise timing requirement. I tried to come up with a reliable digital timing method (TTL wasn't fast enough), finally I 'gave up' and advocated using an analog delay line (we couldn't clock our circuits fast enough for proper digital resolution) -- but he advocated the R/C & threshold delay scheme, using a pot for a production tweak -- implementing the RAS/CAS delay that needed to work over the entire industrial temperature range. That expert (truly, he was a technical expert) lost his contract job because of that conceptual lock-in error. Using a tweak for the RAS/CAS timing over industrial temperature range (CMOS thresholds/characteristics/etc) - it would have been a production/maintenance/support disaster. (Early 1970s') I know that my little anecdote wasn't all that 'short', but I am trying to explain that it is very tricky to find someone who really does give an accurate technical opinion all of the time. Best that one can do -- listen to more than just a few experts with differing agendas, and then use common sense. No-one is immune to both sides of the problem. I do believe that 'technical experts' should try to strive for more integrity* (myself included), and also the user base shouldn't 'buy-in' so very quickly to snake-oil... How does one detect 'snake-oil?' I have no good answer for that. I wish I did. * When I speak of integrity, I don't just mean 'honesty', but I mean the entire package that includes knowing-ones-own-limits. John
  5. B+W photography has another (to me, interesting) facet... Picking the correct developer/process for the specific image. Developers had a HUGE impact on the image. Some developers/film combinations were really great for detail, some for texture, some could even do a subtle (or not-so-subtle) edge enhancement, and even compress the contrast to the extreme. There was a bit of a tone gradiation vs detail tension in film material, and the developers could tweak that tension (or totally blow it away.) There were even developers that could do an almost 'agc' on the exposure level -- almost compensating slightly for over/under exposure. When just doing 'pictures', I'd use something like 'Diafine' or mix my own equivalent. If the high contrast side of the developer (Usually hydroquinone or catechol) were dilute, then there would be an edge enhancement or 'agc' effect. Used properly, catechol (basically hydroquinone with an 'H' in a different place) would be very helpful for mitigating over-exposure. Pure phenidone in a moderately low pH solution could change a fine grain, super contrast film into a good, almost normal contrast range, high detail film. (Very seldom used D76 or a normal-contrast phenidone equivalent -- but it did have it's place.) (Vitamin-C even makes a moderately useful, non-toxic high contrast developer, would be used in combo with phenidone.) There was A LOT to B+W photography -- of course, color had it's own set of controls/variables... I loved it back then. John
  6. That is the kind of thing (maybe not 100% the same) as what I have been saying all along. The big difference is in the 'preparation' for distribution, not so much the medium. (Well, unless the vinyl is the grainy junk that they some used for '45s in the US way back when - must have left some of the metal in from the steel belted tires when creating the 'vinyl' back in the day. 🙂) All of the fine arguments about 'vinyl sounding better' aren't really addressing the issue. More accurately, the version of the recording that is on vinyl sounds better (in some cases.) If the best recording version is on vinyl (assuming minimal ticks/pops/surface noise), and digitize it onto at least CD resolution -- then best of both worlds until a digital version with the same 'preparation' (mastering) as the vinyl album. (Hopefully, without the HF limiting and LF rolloff sometimes used on vinyl 'preparation'.) John
  7. I don't even have a turntable, and not likely to get one. There are so many people that accept the rumble (and it is always there), distortion that comes from heating/stretching the vinyl (the needle) and other things like that -- I have to accept the fact that vinyl must be good enough for some people. Read the 'story' below as an additional reason why I am a bit more tolerant than the digital purist that I would normally be. Also, I have been *initially* fooled by ripped material from audiophile grade vinyl -- thought it was originally digital until I listened carefully to the lead-in rumble (very amazingly slight), the very minimal defects, and looking at the spectogram to confirm. When doing a direct A/B (unless on a bad spot) -- I was amazed. Additionally, the material was tada *DolbyA encoded* -- that was a crazy mix of situations that I still don''t understand how it happened. I still have the rips as a reminder about vinyl someitimes *almost* being good enough. The original recordings were done by a music group whose technical quality is *variable* so that is probably why I was more accepting in that instance -- but it was still *educational* and has blunted my absolutism on the subject. * An old friend gave me the material abt 10yrs ago, and I don't know the provenance... I don't normally keep that kind of stuff around, but it was unique enough to keep as a reminder. John
  8. Where did I claim that digital wasn't good enough? Did you read exactly what I wrote? The statement (paraphrased) that digital technically blows away vinyl should have been early in my statement... Did you read that? Did you read that I said that arguing about digital vs vinyl doesnt' really address the actual problem? If read carefully, I was critical of vinyl and made no serious negative comments about the digital technical quality. In fact, I can get audiophile vinyl (or better) quality from a lot of seemingly inferior digital material because of the digital copy's lack of proper preparation (again, trying to avoid the term 'mastering'.) I sometimes don't read very well when not totally awake... Maybe the same is true for you also? Nuances are difficult to communicate nowadays with the sound-bite type media nowadays. John
  9. IMO (probably more than a guess than actual opinion), the big thing that got the 'elite vinyl' thing started in the first place was very poor preparation and handling of the digitally distributed material. Digital nowadays, even at 44.1k/16bits can blow away any vinyl (except dbx encoded)... period, but the material being delivered by the digital medium has sometimes (often) been inferior to the material provided by the vinyl medium. Most often, which medium has not been the big difference (assuming not using the totally cr*p vinyl that had been used in the past and assuming proper digital technology.) We ALL never realized that we weren't getting the same 'stuff' on digital -- we blamed the poor quality on 'digital'. This started creating the meme that somehow vinyl was 'better' or more 'elite.' I guess it really helped some of those companies that produce the hyper fancy turntables, rigiht? :-). It *does* make sense to immediately archive audiophile quality vinyl onto digital -- get the advantage of probable better mastering, and longer lasting (digital doesn't wear.) There is the cartrige/needle/vinyl distortion and cartridge/preamp noise, freq response, transient response and distortion and vinyl noise -- but in reality, they don't detract all that much assuming good quality equipment and material. Just because I enumerate lots of defects, it doesn't mean that they totally detract from the enjoyment. Poorly prepared (they call it 'mastering' - but I don't want to blame the parties doing the work) material CAN seriously detract from the experience. The very regrettable thing -- a lot of the 'old' music being presented in a very inferior way. Nowadays, even vinyl is sometimes poorly mastered -- and it isn't the person doing the preparation (mastering) fault -- it is penny pinching and bad documentation. IMO -- by focusing on the distribution mechanism (other than stuff that decreases freedom or obscures the material for political, economic reasons), the real problems aren't always being addressed. Of course, nonsense that adds an aspect of DRM or some kind of access control -- those DO diminish from enjoyment. When I had/made lots of money, I'd pay true top-dollar for the best quality, but if they added some kind of DRM -- might as well buy a cheap 45 -- I'd enjoy that as much -- both DRM and bad vinyl grate on my nerves. My two cents -- I just don't believe in the idea that vinyl itself is all that beneficial, other than as access to properly handled/mastered material (and access to material that is only on vinyl.) Nothing wrong with vinyl -- and it is nice to have something that can be physically played given a planet of the apes scenario, but by itself, vinyl has ZERO technical advantages for ultimate quality. John
  10. Oh man -- you are right about the 'replay side' being hyper problematical. That IS the bad side of NR systems -- the record (encoding) side on the Dolby A/SR systems is actually a bit more 'pure'. I keep on doing a successive improvement -- just did one on the DHNRDS yesterday (will probably not be in the first actual release), where I made a slight mistake in an improvement -- already still blowing away the HW version. Bottom line: I agree with your sentiments -- but also have to say -- we (the public in general -- not audiophiles per se) have been accepting quite a bit of distortion in our listening material. It has been 'hidden' by the fact that such distortion isn't measured by simple test tones -- and the NR systems can appear to be pretty clean with those kinds of tests. It is kind of like the 'TIM' of the olden days. I have been listening to better decoded material -- so beautiful -- but makes me really feel bad that the normally available copies are either decoded with distortion or feral DolbyA. The ONLY reason why I can hear the more clean version (DHNRDS IS NOT PERFECT) is that I have some software that really digs into the signal. I have some 'Olivia Newton John' recordings that are -- oh so clean and beautiful. Basically, I have NEVER heard some of the songs sound so very clean. (For the curious, a few examples can be provided -- I do a mass decode based on the latest experimental decoder every night.) The compander with complex interactions (like A and SR) doesn't make accurate decoding very easy. DBX is easy to decode, but has other defects. Doesn't seem like there were any perfect answers!!! John
  11. Yes -- that is the main thing. Distortion is the big bugaboo... Excess bandwidth opens up to more IMD reaching back into the audible range. Almost all normal recordings (not ALL, but allmost all) into the 1990s' have been touched by analog noise reduction systems. Such systems are a nice, very effective source of distortion. Such distortion is usually not very measurable by simple (even multiple) test tones. The war that audio perfectionists should be fighting (if they are true perfectionists) is DISTORTION and good frequency response up to about 20kHz (plus or minus.) This also includes good transient response. Distortions are what makes the difference when there is an excess frequency response and material 'up there'. Of course -- we who know -- a lot of the 'material' above 20kHz in actual, distributed recordings is indeed NR distortion (that is, for the material into the 1990s.) Whatever 'audio' there is above 20kHz just adds to the distortion in the audible range given real-world analog hardware. PS: part of my reason for extreme sensitivity against distortion is that I have heard/seen how much damage is done by at least some of the old NR systems. It is amazing how bad. If the distortion could be measured as easily as normal HD or NORMAL IMD -- it would never have been tolerated. John
  12. There are also DEFINITELY nonlinear mechanisms that can even be used to ultrasonically direct vocal messages to individuals from a long distance -- however, we aren't typically talking about such levels when listening to music from normal transducers. Normal level ultrasonics aren't enough to make this situation happen -- it requires relatively high levels to drive the hearing system into deep nonlinearity. Also, such mechanisms would not have exceptionally linear transfer functions.
  13. I had a root account on ihnp4 :-). (explanation -- ihnp4 was one of the more common servers on the bang path -- routing was mostly not automatic -- but some servers had a little more inteligence.) ihnp4 was very common bang path constituent for UUCP networks also. Nowadays, everyone can route to anyone. John
  14. Are you claiming that all senses of vibration are encompassed in what is heard? That kind of 40kHz audibllity might not be through hearing, but another sense of vibration. I can detect some kinds of vibration from senses other than hearing. Even if the 'ears' detect that vibration, people weren't saying that they 'heard' the vibration, but rather they became 'restless'. Okay, some kinds of so-called music makes me restless, but obviously not the same mechanism as the 40kHz vibration does. John
  15. I never argue about what people prefer, I argue about what can be heard. John
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