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Post by audiobill on Oct 12, 2015 4:29:07 GMT -5
Since digital recordings began in the early '80's, and not much worth listening to (with the exception of Dire Straits) has been recorded since the early '70's, no problem!!!
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KeithL
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Post by KeithL on Oct 12, 2015 10:32:47 GMT -5
I don't disagree with any of your technical comments - but I do still consider there to be a significant amount of personal preference involved - as well as variations based on specific situations. (Where we seem to disagree is that I consider "accuracy" to be a technical absolute - and something separate from "audibility" - and "a goal for its own sake" - at least when practical. While masking "usually works as stated, for most people, under most circumstances", at another level, masking is usually not absolute; in fact, it depends on all sorts of factors... and many of the generalizations on which psychoacoustics is based simply aren't always 100% true. (I haven't read the particular textbook you mentioned, but I'll still bet that you'll find the text peppered with phrases like "usually" and "most people" and "under most circumstances"). I picked window glass for my analogy for a very specific reason. If you look at a typical piece of windows glass, it looks "clear". However, if you place several different pieces of "clear" glass next to each other, you will usually find that there are subtle distinctions of color between them - which are only visible when you look at them next to each other. This is because of an optical version of masking (where our eyes and brain adjust to see things that are more or less clear as "clear" and things that are more or less white as "white"). In some situations, like the "whiteness" of a white surface, the masking depends on what's nearby (you'll see an off-white wall as white until and unless you have something to compare it to); in other situations, it is in fact a matter of mental focus (you don't notice a smudge on the windshield until your attention is drawn to it, at which point it continues to be a distraction until you clean it). I generally find that a high quality MP3 or AAC file sounds quite like the original - and I might not notice whether I was listening to a WAV file or a 320k MP3. However, if I specifically start looking for recordings that sound different between them, and further start concentrating on individual sounds that don't sound the same on both, I find that that the perceptual masking sometimes "breaks down" (just as I notice flaws in glass if I hold a piece of graph paper up behind it), and I would have little difficulty in creating a specific test signal that made the flaws obvious. Once common example is combinations of pure tones, which seem to be less susceptible to masking, and which do occur in modern electronic music quite often. (And, of course, from a purist point of view, if I can find a single example of a test signal where the masking isn't 100.0% perfect, then "it doesn't work all the time".) Likewise, I find that the differences between different DAC filters are audible on certain sounds - and usually only if I'm listening for them. However, now that I'm aware of this, I DO listen for that telltale difference. In the case of DACs, while - as a generalization - pre-ringing is more audible than post-ringing (because it isn't fully masked), there does still seem to be a significant amount of personal preference involved. The reality is that, while it's quite possible that both are equally audible to anyone listening for them, some people seem to find pre-ringing to be especially annoying, while others, while they may be able to perceive it, don't seem to be bothered nearly so much. If you check discussion forums about "how different DACs sound", you will find many people who prefer certain non-oversampling DACs, and DACs with certain filters, whose measurements show that they have minimized pre-ringing, but at the expense of a significant high-frequency roll off. Likewise, other people find those DACs to sound "dull", and don't seem to notice which type of ringing, and how much, is present. And you will find yet other people who insist that they don't hear any difference at all. (I'm pretty sure that anyone could be trained to hear these differences - but, at least to begin with, many do not.) Now, as for signal "correction", like using a filter to shift pre-ringing to post-ringing.... I'm usually in favor of that, and I doubt that too many recordings (or any) were deliberately mastered with a lot of pre-ringing as "an artistic choice". (However, since I've never listened to a copy of a file that was "fixed" with Dolby's filter next to the original, I'm also not totally certain that it won't change the sound otherwise. It would also be interesting to hear what happens when that filter is run on a file that already has minimal pre-ringing.) However, to jump back to my choice of glass as an analogy..... I think it was very apt. Glass is either clear or not. You can equivocate, and you can make claims that given flaws will or will not be visible, and we can discuss how many people will notice which flaw, or which flaw is worse, or who has proof that, under most circumstances, most humans won't notice one flaw as much as the other, but I hope we can agree that simply being totally transparent, and so having no flaws at all, would be "the ideal situation for a piece of glass". (In other words, just like I color calibrate my monitor before I start wondering which aberrations might or might not be visible, and I'm not going to deliberately buy a piece of glass that I know is flawed, I prefer to avoid any inaccuracies knowingly added by any sort of processing before I start wondering which ones may or may not be audible.) That is indeed true.... however, the important thing to remember is that upsampling in and of itself does NOT improve anything. What's happening is that, when you convert a digital audio signal back into analog, you MUST apply a filter to the resulting audio to remove all energy above the Nyquist frequency. With a DAC converting a 44k CD audio signal, with no oversampling, in order to avoid compromising the quality of the analog audio output, this would require a filter that was flat to 20 kHz, but had attenuation of around 80 dB at 24 kHz. As it turns out, a filter that meets those requirements is impractical to build and produce - and trying to do so always involves unacceptable compromises. What upsampling does is to use some mathematical trickery to increase the sample rate, and so the Nyquist frequency. What you very much need to understand is that oversampling does NOT improve audio quality; what it does is to alter the signal in a way that is "quality neutral", but which then makes it simpler to design a filter which DOESN'T degrade the signal quality. Oversampling for this purpose can be done explicitly, or it can occur as part of the conversion process itself. Virtually all modern DACs use some form of oversampling (including Sabre DACs, delta-sigma DACs, and the Schiit Yggdrasil); the exception being DACs specifically billed as "non-oversampling DACs". In this context, since the oversampling process is occurring inside the DAC, you can't differentiate what audible differences, if any, it introduces; it's simply part of what defines the sound character of the particular DAC. By upsampling the digital audio (in addition to what occurs inside the DAC) you are introducing another step where the sound quality may be altered - and so another opportunity to choose an option whose sound you prefer - but you need to remember that any change you hear can only be due to a loss of accuracy. (Of you're a purist, then you realize that, if the glass in a windows is clear, then you can't even see it; if you choose between different panes of glass because they look different, then you must accept that the choices aren't actually clear glass. Of course, if you're not a total purist, then it's one more place where you can introduce options and choices.) And, of course, since we're talking about upsampling a "standard res" file, none of this has anything whatsoever to do with the idea that a high-res file could contain extra detail that "won't fit" in a non-high-res file - assuming that there's information there to begin with and that we will be able to hear it. (In other words you need to differentiate between enabling accuracy - which is possible, and creating accuracy - which is not.) Only caveat, the human hearing system is non linear in a lot of ways. The part that's audible to us needs to be accurate, whereas the other part does not. It means that, first, we need to study human hearing. Only then can we start having a meaningful conversation about accuracy. Because if the measured magnitude of a certain type of error in a signal is large, then if this error is completely inaudible to humans, the only conclusion that can be logical is that under this specific set of circumstances it simply doesn't matter the fact the signal is highly inaccurate. Whereas, if another type of error in this same signal measures small, then if we can hear it despite the fact it's small, it *does* matter despite the fact it's small. So yeah, obviously you can *talk* about things like clear glass. But the actual reality is that humans don't *hear* sounds that way. It just isn't an accurate way of describing how the human hearing system works. I know, this is all very counter intuitive. However, once you have been reading a few chapters into the book titled "Psychoacoustics: Facts and Models" by Hugo Fastl and Eberhard Zwicker, that's when you will start to discover that our ears really don't treat accuracy the same way engineers are trained to. You see, pre-ringing has a very strong tendency to be much more *audible* than post-ringing. This is not the same thing as personal *preference* about sound, or about being a "purist". It's called masking, and electronic measurements lose their meaning, or value if you ignore the auditory neuroscience that is used to describe masking. So I have to firmly disagree with you regarding signal *quality* here. The accuracy, or quality of information that is reproduced, or reconstrued from digital data depends not only on the interpolation method used, the actual data itself, and that which the information describes, but on the goal that we need to achieve by using that information. The goal, which, if we can help it, isn't to let the time-smearing effect of pre-ringing artifacts muck up a percussion instrument's sharp transients. That's the good hypothesis. The good news is that some flaws in the ADC can be corrected by changing the data that came out of it. Pontification on whether this correction should happen before, after, or during transfer of the data to the DAC unit is quite sadly missing the point entirely. |
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KeithL
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Post by KeithL on Oct 12, 2015 12:04:35 GMT -5
Absolutely true...... But, when I listen to that distorted guitar, I want to hear that distortion exactly as the musician and the recording engineer recorded it. (I don't want it sounding worse - or even better - because my system is changing it.) Sometimes various distortions and nasty noises are the most difficult things of all to get right. (Try getting a recording that sounds exactly like a real piece of glass breaking...) I think it's fun to observe how many worry about .0000001% jitter or distortion specs while listening to distortion laden, compressed and overdriven recordings of rawk bands from decades ago. Just check the "What are you listening to now" thread here. A great point. The distortion introduced by a decent audio system pales besides that introduced (some deliberately, such as fuzz-tone guitars)) by electronically amplified instruments |
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Post by geebo on Oct 12, 2015 12:40:41 GMT -5
Absolutely true...... But, when I listen to that distorted guitar, I want to hear that distortion exactly as the musician and the recording engineer recorded it. (I don't want it sounding worse - or even better - because my system is changing it.) Sometimes various distortions and nasty noises are the most difficult things of all to get right. (Try getting a recording that sounds exactly like a real piece of glass breaking...) A great point. The distortion introduced by a decent audio system pales besides that introduced (some deliberately, such as fuzz-tone guitars)) by electronically amplified instruments +1. I want undistorted distortion. |
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Post by monkumonku on Oct 12, 2015 12:54:07 GMT -5
Absolutely true...... But, when I listen to that distorted guitar, I want to hear that distortion exactly as the musician and the recording engineer recorded it. (I don't want it sounding worse - or even better - because my system is changing it.) Sometimes various distortions and nasty noises are the most difficult things of all to get right. (Try getting a recording that sounds exactly like a real piece of glass breaking...) A great point. The distortion introduced by a decent audio system pales besides that introduced (some deliberately, such as fuzz-tone guitars)) by electronically amplified instruments The sound of glass breaking is easily recognizable and people can tell quickly if it sounds realistic or not. That said, there still are differences in the sound depending on the size of the glass object, the surface on which it is broken, etc. so how would you really know how realistic it was? In the case of faithfully capturing guitar distortion, how would anyone know if it was being exactly reproduced as played and recorded? Unless you were able to compare the two side by side, there is no way to know what the original really sounded like. |
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KeithL
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Post by KeithL on Oct 12, 2015 13:44:55 GMT -5
This seems to be a bit of a sort of circular argument. The way I would like to know that it's accurate is by knowing that my equipment is accurate. I'm pretty sure that the guys on Avatar have bright blue skins - because I know that my TV renders colors more or less accurately; and I can tell for sure almost exactly what tint of blue they are on my computer monitor because I calibrate it. Since, unlike breaking glass and real human faces, I don't have any actual experience of what Avatar aliens should look like, my only recourse is to trust my equipment to be correct. (And, if I had to put a protective glass covering in front of my TV screen, I would much prefer to start with a truly measurably transparent sheet of glass than with one that, while it doesn't measure that way, is claimed to "not produce a visible change in the picture". I may not know for sure that those blue alien faces are the perfect right color, but the fact that all those colored squares from my calibrator measured dead on definitely gives me better odds that they are. The basic principle is simply to minimize unknowns whenever possible.) I most definitely wouldn't be happy if I heard a distorted guitar and wasn't quite sure whether the guitar was really distorted, or my stereo was overloaded. And I'm not at all sure I would personally recognize the difference between a Fender amp and a Marshal head, but I would still like some degree of certainty that I can base my thoughts on the subject on the first principle that what I'm hearing out of my speakers is pretty close to what was being picked up by the microphone (or, at least, what the recording engineer wanted it to sound like). In short, one way that you can know if it's right or not, within a reasonable degree of certainty, is by knowing that your equipment is capable of reproducing it correctly. (You can't know much about the accuracy of the recording chain up until the recording, unless they tell you, but you can do a lot towards ensuring that everything on "your side of the playback line" is accurate.) Absolutely true...... But, when I listen to that distorted guitar, I want to hear that distortion exactly as the musician and the recording engineer recorded it. (I don't want it sounding worse - or even better - because my system is changing it.) Sometimes various distortions and nasty noises are the most difficult things of all to get right. (Try getting a recording that sounds exactly like a real piece of glass breaking...) The sound of glass breaking is easily recognizable and people can tell quickly if it sounds realistic or not. That said, there still are differences in the sound depending on the size of the glass object, the surface on which it is broken, etc. so how would you really know how realistic it was? In the case of faithfully capturing guitar distortion, how would anyone know if it was being exactly reproduced as played and recorded? Unless you were able to compare the two side by side, there is no way to know what the original really sounded like. |
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Post by yves on Oct 12, 2015 14:20:07 GMT -5
see things that are more or less clear as "clear"  |
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Post by monkumonku on Oct 12, 2015 15:11:09 GMT -5
This seems to be a bit of a sort of circular argument. The way I would like to know that it's accurate is by knowing that my equipment is accurate. I'm pretty sure that the guys on Avatar have bright blue skins - because I know that my TV renders colors more or less accurately; and I can tell for sure almost exactly what tint of blue they are on my computer monitor because I calibrate it. Since, unlike breaking glass and real human faces, I don't have any actual experience of what Avatar aliens should look like, my only recourse is to trust my equipment to be correct. (And, if I had to put a protective glass covering in front of my TV screen, I would much prefer to start with a truly measurably transparent sheet of glass than with one that, while it doesn't measure that way, is claimed to "not produce a visible change in the picture". I may not know for sure that those blue alien faces are the perfect right color, but the fact that all those colored squares from my calibrator measured dead on definitely gives me better odds that they are. The basic principle is simply to minimize unknowns whenever possible.) I most definitely wouldn't be happy if I heard a distorted guitar and wasn't quite sure whether the guitar was really distorted, or my stereo was overloaded. And I'm not at all sure I would personally recognize the difference between a Fender amp and a Marshal head, but I would still like some degree of certainty that I can base my thoughts on the subject on the first principle that what I'm hearing out of my speakers is pretty close to what was being picked up by the microphone (or, at least, what the recording engineer wanted it to sound like). In short, one way that you can know if it's right or not, within a reasonable degree of certainty, is by knowing that your equipment is capable of reproducing it correctly. (You can't know much about the accuracy of the recording chain up until the recording, unless they tell you, but you can do a lot towards ensuring that everything on "your side of the playback line" is accurate.) The sound of glass breaking is easily recognizable and people can tell quickly if it sounds realistic or not. That said, there still are differences in the sound depending on the size of the glass object, the surface on which it is broken, etc. so how would you really know how realistic it was? In the case of faithfully capturing guitar distortion, how would anyone know if it was being exactly reproduced as played and recorded? Unless you were able to compare the two side by side, there is no way to know what the original really sounded like. So then if it is accuracy you want, stay away from tubes and vinyl, then.  |
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Post by audiobill on Oct 12, 2015 15:26:13 GMT -5
But if i's great sound you want........
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Post by geebo on Oct 12, 2015 15:54:58 GMT -5
But if i's great sound you want........ ...then get some good digital recordings and a fast SS amp to play them...  |
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Post by audiobill on Oct 12, 2015 16:05:26 GMT -5
Yeeeeccchhhh, been there never again!!
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Post by geebo on Oct 12, 2015 16:42:13 GMT -5
Yeeeeccchhhh, been there never again!! Yep, I'll snap never go tick back to ssss vinyl again. So click glad to be pop done with it. It's so nice to have clean dynamic music. |
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klinemj
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Post by klinemj on Oct 13, 2015 15:40:16 GMT -5
I have a digital copy of a tree falling in the forest AND and analog copy on vinyl. Other than some pops/clicks on the vinyl, I can't hear the difference, but of course...since nobody was there to hear the original, each recording is perfectly silent.
Mark
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Post by geebo on Oct 13, 2015 15:57:34 GMT -5
I have a digital copy of a tree falling in the forest AND and analog copy on vinyl. Other than some pops/clicks on the vinyl, I can't hear the difference, but of course...since nobody was there to hear the original, each recording is perfectly silent. Mark Except for the clicks, ticks, hiss, snaps, crackles and pops, right? |
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Post by garbulky on Oct 13, 2015 17:32:26 GMT -5
Snap crackle pop. Ask novisnick about that on his fantastic rega turntable! |
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Post by yves on Oct 15, 2015 13:21:00 GMT -5
Yeeeeccchhhh, been there never again!! Yep, I'll snap never go tick back to ssss vinyl again. So click glad to be pop done with it. It's so nice to have clean dynamic music. The sound of vinyl records doesn't have noticeable clicks or pops if you 1. thoroughly clean the records by using the right cleaning method, and 2. manually post-process the remaining clicks and pops in iZotope RX 5. On top of that, on a good turntable setup the hiss is usually subliminal. EDIT: The latest album from Keith Richards sounds more dynamic on vinyl. |
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Post by geebo on Oct 15, 2015 13:29:27 GMT -5
Yep, I'll snap never go tick back to ssss vinyl again. So click glad to be pop done with it. It's so nice to have clean dynamic music. The sound of vinyl records doesn't have noticeable clicks or pops if you 1. thoroughly clean the records by using the right cleaning method, and 2. manually post-process the remaining clicks and pops in iZoptope RX 5. On top of that, on a good turntable setup the hiss is usually subliminal. EDIT: The latest album from Keith Richards sounds more dynamic on vinyl. I'm not new at this. Listening to vinyl is like having someone snap their fingers randomly in one ear and hiss in the other while you're trying to enjoy some music. And it gets worse as the album gets played more and more. No, I've listened to vinyl for a long time and I'm so glad to be past it now. |
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KeithL
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Post by KeithL on Oct 15, 2015 13:59:24 GMT -5
I'm inclined to agree with Geebo on this one... I'm one of those people who, back when I owned and played vinyl, would flinch every time there was a tick or pop (usually followed by stopping the record, giving it a good cleaning, then crossing my fingers that the pop wasn't really a permanent scratch). I would also usually buy a second copy of any album I really liked - just as a backup in case my first copy got damaged. I also used to worry about records getting worn, and the possibility that two different pressings of the same album might be slightly different because one was from the beginning of a pressing run and the other was from the end (masters and mothers also wear as they're used, and so change slightly). To me, the biggest single benefit of digital audio is verifiable consistency and reliability. I can make a backup copy of any digital audio file I own; and I can store a checksum and later use that checksum to confirm with 100% certainty that the file hasn't changed or become damaged. In fact, with a few mouse clicks, I can have my computer verify that every single digital audio file on my entire music server is still perfect. (When I RIP a CD, I can even confirm, with an online database, that my RIP is absolutely positively perfect... so I never have to wonder.) Even beyond that, no playback system is perfect, so even a great digital playback system may have the rare tick or dropout... but, unlike with vinyl, I don't have to worry that my original has been damaged. (Since digital files rarely become corrupted, and are easy to verify, and I have a backup copy anyway, I can relax knowing that it was just a transient occurrence and not a scratch or other permanent damage that will be there every time I play that song.) Once thing to remember, though, is that, because of the limitations of vinyl production, there will always necessarily be at least slight differences between vinyl pressings and digital files made from the same master (at the very least, high level high frequencies will have to be limited to protect the cutting lathe). It's not just a matter of feeding exactly the same signal into a different type of recording device. And there's also the possibility that more deliberate changes will be made to make sure that the vinyl version sounds different (perhaps because the artist believes that "vinyl should be a different experience" or because the mastering engineer or producer believes that customers have slightly different expectations). As such, it's not at all surprising that the vinyl version might sound different - for better or worse. However, notwithstanding "artistic choices", a 24 bit digital file is capable of much flatter frequency response, lower THD, and wider dynamic range than vinyl - if the mastering engineer chooses to take advantage of them. The sound of vinyl records doesn't have noticeable clicks or pops if you 1. thoroughly clean the records by using the right cleaning method, and 2. manually post-process the remaining clicks and pops in iZoptope RX 5. On top of that, on a good turntable setup the hiss is usually subliminal. EDIT: The latest album from Keith Richards sounds more dynamic on vinyl. I'm not new at this. Listening to vinyl is like having someone snap their fingers randomly in one ear and hiss in the other while you're trying to enjoy some music. And it gets worse as the album gets played more and more. No, I've listened to vinyl for a long time and I'm so glad to be past it now. |
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Post by drtrey3 on Oct 15, 2015 14:00:47 GMT -5
Listening to my Chicago II record that I have had since 1972 sounds like that.
Listening to my Chicago II record that I bought in 1985, after I knew how to take care of records, sounds nothing like that.
Trey
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KeithL
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Post by KeithL on Oct 15, 2015 14:10:09 GMT -5
I'm sorry, but I just have to call you on this one..... So, we're going to start with vinyl, presumably because we believe that a digital file would somehow not sound as good.... Then we're going to turn that analog audio into a digital file or a digital audio stream so we can process it with Izotope RX.... That sure sounds to me like we're going to be adding together all of the flaws of vinyl and the flaws of digital - rather than avoiding either.... (Then, of course, doing our best to fix any we notice - digitally.) If we're going to go through an ADC, and then do digital processing to repair some flaws anyway, wouldn't it make more sense to save the output after we fix it with Izotope RX, and simply play that digital file directly next time? In fact, assuming that what we're listening to was mastered digitally, then wouldn't it just make sense to get a copy straight from there - and so avoid introducing flaws that we then must fix? I'm just sayin..... Yep, I'll snap never go tick back to ssss vinyl again. So click glad to be pop done with it. It's so nice to have clean dynamic music. The sound of vinyl records doesn't have noticeable clicks or pops if you 1. thoroughly clean the records by using the right cleaning method, and 2. manually post-process the remaining clicks and pops in iZotope RX 5. On top of that, on a good turntable setup the hiss is usually subliminal. EDIT: The latest album from Keith Richards sounds more dynamic on vinyl. |
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