Why 24 bit audio and anything over 48k is not only worthless, but bad for music.

Discussion in 'Sound Science' started by keanex, Apr 30, 2014.
  1. KeithEmo
    Video is actually a rather more interesting subject than audio.

    As consumers we do NOT have access to uncompressed video.
    ALL video we have access to, including the video on Blu-Ray discs and 4k UHD discs, is significantly compressed.
    And, if you do have the opportunity to compare actual uncompressed video to a Blu-Ray or 4k disc, you will see that there ARE visible differences.

    Use your computer to generate a few seconds of true uncompressed video - especially containing sharp lines and fine print.
    Take a bunch of perfectly sharp still frames and combine them into a video.
    Compress it using any of the standard video compression profiles, and you will see that there are in fact significant visible differences, all of which relate to loss of detail or motion or color space compression.
    You may find that the losses aren't especially noticeable, and you may be able to trade objectionable artifacts for less objectionable ones, resulting in an "overall improvement".... but there will always be fidelity losses.

    Video encoders are notorious for omitting random noise like film grain that was present in the original.
    (They do this because true random noise is difficult to encode, and so uses up bandwidth that "could better be used for more important details".)
    However, some producers, and some fans, complain that the "film look" of the video is destroyed when the film grain is removed.
    (And, if your new digital audio recording omitted the tape noise that was present on the original master tape, would you describe it as an accurate reproduction or not?)

    (Incidentally, Darbee is not noise reduction..... it is a sort of dynamic color and detail enhancement process. And, no, I'm not fond of the look it delivers.)

     
  2. bigshot
    Generally accepted science is the Nyquist Theory, the principles of acoustics developed at Bell Labs in the 20s, and the established thresholds of human perception.

    Have you done any controlled listening tests yourself? If not, get to it. You’ll understand better what we’re talking about.

    When you talk about compression artifacting, there is absolutely no point generalizing unless you're going to specify the codec and bitrate you're talking about. There's blatantly obvious artifacting and there's completely imperceptible compression. Darbee is the same. It has a continuous scale from absolutely no difference to horrible over sharpening. But if used properly, it is a great tool.

    Absolutism gets you nowhere in digital audio and video. "Purity" theories were great in the analogue days where every layer of processing added noise and there was generation loss. It's a whole new world with digital. You can instantly see the effect of processing in a direct A/B comparison. You can process and compress and actually come out with something that looks and sounds better than the original. I love those tools and I know how to use them effectively. If I was afraid of them, I'd be stuck with what I'm handed. No thanks!
     
    Last edited: Nov 10, 2017
  3. pinnahertz
    Your FM stereo description is a bit wrong. The L-R channel is carried on a double-disband suppressed carrier channel centered at 38kHz, not 19kHz. If a 19kHz subcarriers were used modulation side bands would end up in the audio band. 38kHz was chosen because the lowest modulation sideband lands at 23kHz, above the audio band. Double sideband supressrd carrier modulation was chosen for efficiency, no bandwidth was burned up be a carrier as it is in basic AM. The 19kHz pilot, which is required to regenerate the suppressed 38kHz carrier for demodulation, is injected 20dB below 100% modulation, then taken down another 20dB by de-emphasis (yes in mono radios too). So the most 19kHz you'd get out of any FM radio would be 40dB below 100% modulation. The better stereo tuners would have included a pilot null circuit that could be aligned for another 30 to 50dB of pilot reduction. The chances of any audible 19 kHz coming out of the output is very minimal indeed, certainly far too low to be filled as "pressure". In fact, the only 19 kHz leakage problems I'm aware of have to do with it beating against the bias frequency of a tape recorder.

    In my youth, I was blessed with hearing up to 23kHz (which should partly address that issue in one of your other posts), verified by the use of a sine wave oscillator in electronics lab. Horizontal fly back frequency in television drove me nuts, and the ultrasonic burglar alarms used in retail stores of the time caused me actual pain ( they ran in the low 20 kHz range). However, I built a vacuum tube – based Heathkit stereo tuner with virtually no special handling of the pilot other than a null circuit, and I was never bothered by 19 kHz from that, other than the bias beat in my tape recorder.

    I disagree the 20 kHz plus is important at all for hi fidelity music reproduction in and of itself. I do believe that systems that are severely limited in high frequency response can suffer from nonlinearities causing intermodulation products that can become audible, but high frequencies themselves above 20 kHz are not audible. If good high frequency Linearity can be maintained such that Intermodulation products are kept very low, I see no need for greater than 20 kHz response.
     
  4. pinnahertz
    I trust you aren't addressing that comment to me. I hate generalizations without qualification.
    And as I addressed briefly in my previous post, you'd have been wise not to make that bet. The fact that a high level, high frequency test tone was audible to me up to 23kHz at one point in my life means nothing in terms of that frequency and above contributing in any way to music preproduction. You are probably aware that the high end of human hearing is highly variable and depends on many factors, the big ones being age and hearing damage. The range of 15kHz detection, for example, is over 90dB across a wide population segment. That's 90dB, not 9 or so. 90. And believe it or not, that's partially correctable! But that should tell you a bit about how human hearing averages out. Young undamaged ears may detect high levels of sustained test tones above 20kHz, but over 20 years of age, that's pretty much gone already.
    Please understand that hearing high frequencies is not a binary situation. It's not "hear it or you don't", it's a question of level vs frequency vs threshold of detection. Hearing response has quite a radical curve to it, even in ideal, young, undamaged ears. But the curve gets very, very steep above 20kHz where, in fact, the threshold of hearing at the threshold of pain intersect somewhere around 140dB SPL. Pretty much no point in designing for that condition, now is there?

    Perfect pitch is completely outside of this discussion. It can be developed, and then later lost. Some come by it more readily, some almost innately, others not as much. And trust me, it's not always a welcome gift. But it has nothing to do with this discussion.
     
  5. castleofargh Contributor
    indeed skepticism should apply to all including ourselves, and to everything including negative results. I believe we don't hang around negative results much because most of us already know how little they prove. I don't believe many aside from the new born objectivists take failure to notice as a huge conclusive result.
    there is a little conflict with that idea when my default stand is to expect no difference, but what else can I do? the open mind approach where we seriously consider and investigate everything ever claimed, leads straight to the 9th dimension of sound that no instrument can measure but some old dude in a chair claims to hear. the need to draw a line between reality and delusion is just too important in this hobby IMO. so I picked the position of the jerk who doesn't believe what people say and goes "vid or it didn't happen".

    to me(and only me for me in my life) the all high res idea is very clear and not mysterious at all. I see what I can get in measurements from increasing it and changing variables. I see how different DACs deal with redbook with various approaches and degrees of success in being transparent. I can test a bunch of situations for my own gears and my own hearing, and have done it many times over the years. I'm also clear on how money is more important to me than very small doubts. something unrelated to sound but very significant to me. just like some other guy will make himself sick with insecurity, and if using highres can relax him, then obviously he should go high res. and for the guy with the crappy NOS DAC that some fool made with no or very bad filter, it's very possible that high res(or at least upsampling) will really improve things. and whatever other situation is fine. whatever is significant in somebody's life for whatever reason, that's something worth dealing with for that person.

    what makes the highres issue complicated is like you suggest, how everybody seems to be asking different questions about different situations while being different people. what's worst is when after that they assume that any idea/conclusion they reach is applicable to the rest of the world and every other situations.
    even within the noticeable, people tend to have very different perspectives. someone will go "I noticed that hat on that guy when we passed in the subway full of people". and even if the next day I go looking for that guy with the hat and I end up finding him, the meaning of noticeable takes a special sense. I could have walked there for 10 years without noticing that hat. or I could have seen it and not care "oh a hat, so what?". or I could have seen it and from that day on, could never not see it when I passed there. at some point I could become so obsessed that I would think I see the hat everywhere even when it's not there. or I would see another hat and assume it's THE hat. all those situations encompass "noticeable" but are night and day different when it comes to personal experience and the significance of it. so even the correlation between noticeable and significant is a delicate thing. and with highres, we're often at a point where just noticeable is hard to demonstrate. so I don't find it excessive to assume that for most people, highres is a trivial event as far as the sound of musical content is concerned. because they might still be of that opinion if noticeable was clearly ascertained. that's how much mental headroom I have on this ^_^.
     
  6. Whazzzup
    well thats that. :relieved:
     
  7. bigshot
    Unfortunately, there's ample evidence that high data rate audio doesn't totally deal with audiophilia nervosa. It just makes the doubt move on to a different area... Instead of sampling rate, they start worrying about jitter in their DAC or how clean the caps are in their amp. They just bounce from variable to variable, spending money and never finding total relief. The problem with insecurity is insecurity. It doesn't have anything really to do with what the person is feeling insecure about.
     
  8. frodeni
    In interpretive qualitative research, there is no usage of bias. Bias is related to positivist research, and is not used in the tradition of interpretive research. Actually, objecting to how bias is traditionally used in the nature sciences, rejecting it completely, is so comon, that there is a large number of papers dealing with it. For really good reasons. Well founded, and well argument ed reasoning.

    The notion that everything needs to be statistical significant is also a highly contested argument. Also, for very good reasons. There are plenty of papers, of highly regarded scientists, that argue against the need for being statistically significant.

    As for meaningless, well, what do you mean by "in fact completely meaningless"? When did meaning become a fact? How do you factually prove meaning?

    Same thing. How do you guys even know that anyone feel insecure? Care to prove how you arrived at that conclusion? How can you possibly know what other people feel? How do you know, what caused people to feel how they do?

    Just as a warning, answer with care. You also need to apply your epistemology, at the topic of this tread. Good luck with that, give the position you are pushing.
     
  9. bigshot
    I can do that very easily. I have a simple blind listening test that takes two very difficult passages of music to compress without artifacting and runs it though a variety of codecs and bit rates. It's a very easy way to determine where your own threshold of transparency lies. I can offer it to you to as a single lossless file containing ten different encodings, from lossless all the way down to MP3 192. All you have to do is listen to the samples and rank them from best to worst. Easy, right? If you'd like to take the test, all you have to do is tell me if you want FLAC or ALAC.

    OK. Now it's time for your response. Will you agree to take the test? That depends on whether you really *want* to know if you can hear a difference. If you take the test and determine that you can't hear the difference with a particular codec and bitrate, will you stop ripping to a lossless format and use compressed audio? If not, why? Because you would feel more secure knowing that it's "lossless" regardless of whether it sounds identical or not.

    My test doesn't just determine the level where compressed audio becomes audibly transparent. It also tests whether you will allow knowledge of the truth to override your insecurities about lossy codecs "throwing out something you might need". Most audiophiles just refuse to take the test because being wrong is preferable to them than knowing the truth. That shows that ego is the real force driving their decisions, not audio fidelity. I can test for transparency, insecurity and ego all with one simple test.
     
    Last edited: Nov 11, 2017
  10. frodeni
    Sure. If you dare to. Sure you want me to flaw your test? I am not scared of any testing, what so ever, rather I embrace it. I also embrace my current beliefs, assumptions, experience, and knowledge. Please, send me this test of yours, please explain it in detail, and the ethics of how you will use my results. Please describe the limits of usage, when the data will be destroyed, and the scheme you have to vet your usage of the data I supply to you? Also, describe what kind of research this is a part of, what tradition this is conducted within.

    Also, please note that I hardly can tell any difference on sound quality using certain USB ports on my laptop, differences between uncompressed and lossy compressed. I just don't. Guess what my results will tell you. Give some thought.

    As for you proving any insecurity, that is plain out false. You have not even established any correlation in any form with any insecurity. You simply have not even found any valid prove of any insecurity. None. It is all in your head. Which is kind of ironic.

    If I do this test of yours, how do I know that you will publicly refrain from using it to mock me, making all sort of false claims of what I supposedly feel? Who will vet your claims? What makes them capable to vet you? In what tradition will you be vetted?

    So great! Send me this file of yours. This is going to be great fun. Just not the fun you expect it to be.
     
  11. bigshot
    The single ground rule is that you can only listen. No opening up the file and peeping at waveforms. Normal listening levels the same way you listen to music normally. If you cheat the test, you're only cheating yourself. (People have tried and it doesn't work. I will be able to tell.) You can listen on any equipment you want.

    You rank the ten samples from best to worst. Discerning the degree of artifacting is as important as discerning lossless vs lossy. You send me your list. I send you back your results in PM. It won't be published or publicly discussed unless you want to. This isn't about ego. It's about you finding out the truth for yourself. Only you and I will know. If you discuss the test publicly, then I will discuss your results too. If you don't, I won't. PM me and I'll send you the file.
     
    Last edited: Nov 11, 2017
  12. frodeni
    Oh boy. Sure. What ever.

    Just answer the questions, particularly the one about how you know what other people feel.

    If you cannot behave like a scientist, do not pretend to know how to.
     
  13. Strangelove424
    I have been lucky enough to work on uncompressed film masters in my career, with files large enough to saturate ethernet connections to the server. With a nice IPS monitor, it is a beautiful thing to behold, especially if the movie is an animated one. The gradients stand out particularly, perfectly smooth and organic. I never noticed such a startling difference with live action films, which have the resolving limitation of lenses and sensors to deal with. But with computer animated movies rendered uncompressed from software... wow.
     
  14. bigshot
    Didn't I already answer that? Do you want to take the test? Feel free to say no. If you don't want to know your thresholds of perception that's fine. I know where mine is, and I would guess it isn't that different from yours. Did me pointing out that it's strictly a listening test scare you off?
     
    Last edited: Nov 12, 2017
  15. bigshot
    I was inspired to create my home theater projection system when I was able to see The Incredibles at the Frank Wells Theater at Disney. It was very nice, but my own theater with a really good blu-ray is just as good. The only difference is the size. My theater holds about 12 people and we sit closer to the screen. The Disney theater holds about 50 and you sit further away. The end result is the same.
     

Share This Page