Transients and frequencies above 20 kHz

Discussion in 'Audio Hardware' started by 2xUeL, Oct 16, 2016.

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  1. 2xUeL

    2xUeL Forum Philosopher Thread Starter

    Location:
    Albany, NY
    Hey Tony! Yeah you!

    Just kidding. So here's what happened: I was at an audiophile meetup this weekend with the now infamous @Tony Plachy, at which time he told me about the zany thread he recently started about the science behind digital audio. During our conversation, he also explained that the existence of information above 20 kHz can more accurately reproduce the transient of a sound. I knew that a transient is a loud, brief 'burst' at the beginning of a sound, but I did not know what Wikipedia confirmed, that transients "sometimes contain a high degree of non-periodic components and a higher magnitude of high frequencies than the harmonic content of that sound". Tony's point was that a lot of this high-frequency transient information is above 20 kHz and thus nonexistent in 44.1 kHz digital waveforms.

    I don't want to get into a debate about whether or not the average person can perceive frequencies above 20 kHz, no matter how civil the debate is. It turns out that I love 16/44.1k digital audio, but I'm not one bit offended by others who have a distaste for it, and I don't believe Tony would peg me as having an inferior attention to sonic detail as a result (correct me if I'm wrong, Tony ;)). I do, however, want to thank Tony for sharing what he knows both in person and on this forum. I have been a fan of his since I joined four years ago, at which time it was immediately apparent that the guy knows his stuff.

    I will conclude with an open question: What does everyone have to say about the point at which they feel it becomes too much of a chore (or expense) to analyze the finer differences between varied listening experiences? The reason I ask is because with enough money and enough unwavering focus, I can't say for sure that I wouldn't hear a difference between 44.1k and 96k. I haven't heard a difference in the past (on worthy equipment in a worthy acoustic space), but truth be told, that was years ago and I'm open to the possibility that my attention to detail may have improved over the years.

    As per usual, be respectful and no arguments please!
     
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  2. The Pinhead

    The Pinhead KING OF BOOM AND SIZZLE IN HELL

  3. Agitater

    Agitater Forum Resident

    Location:
    Toronto
    Find a friend, purchase 24/96 and 24/192 downloads of some CDs you already own. After giving your friend some instructions, set up your NAS and CD player with identical tracks, give your friend the controls, close your eyes, lean back in your favorite listening chair and have your friend play tracks in succession without telling you which is which. Try to pick the one you like best. You'll find out easily enough. With proper remasterings in 24/9 or 24/192 you might hear an improvement over CD, or you might not if your hearing is middle aged (or older) or damaged or simply not sensitive in certain ways. Shouldn't prevent you from thoroughly enjoying your music anyway at all though. Might have nothing to do with your hearing either; it might be you've got a terrific system and listening room that allows you to clearly hear every nuance and every touted improvement. Or not. Or something in between.

    Are you asking for consensus about what others hear in order to help decide what you should hear? Personally, I think the better move might be to decide what you can actually hear on your own by listening to comparison CDs and files, and then posting your thoughts and conclusions here.
     
  4. I thought transients were artifacts in the audio and the "burst" at the beginning of the sound is the Attack? I only have a self taught understanding of digital audio through the internet and trial and error so I could be wrong.

    also, I did an online audio test, seems I can only hear up to around 15kHz these days. I think the higher rez does recreate the higher frequencies more accurately and lowers the noise floor. Kinda like when you look at a spectrum analyser of a low quality mp3 you can see the tops of the waveform brickwalled at 15khz. Having the extra bandwidth would eliminate the bottleneck.

    Listening to a 192 rip and compared it to a 96kHz rip and I think I heard a more detailed hi hat once., it was a moment that I said wow that was cool. Then again it could have been psychosomatic. The 192kHz rip was from a record I tried to import into iTunes and had to reencode to 96 so the source was the same.
     
    Last edited: Oct 17, 2016
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  5. sunspot42

    sunspot42 Forum Resident

    Location:
    San Francisco
    Unfortunately that's not a very good test, since the CDs could have been cut from completely different masters (indeed, it's almost certain they would have been).

    A better test would be to download a well-regarded 24/88, 24/96 or 24/192 master from someplace like HDTracks, of an album you're familiar with. Then using a tool like Goldwave, create a 16/44 or 16/48 (stick to even factors of the original sample rate) copy of the album (don't forget to use dither - should be an option in your tool or enabled by default).

    Now do comparisons and see if you can tell any difference. More importantly, see if you can determine a preference.

    You might also want to create 16/96 and 16/192 copies and compare those to the 24-bit originals, to see if the increased bit depth makes a difference all by itself.

    And keep in mind even if you can hear a difference, that might be due to issues with your D/A converter, and not some inherent superiority of the higher-res (or lower-res, for that matter) files.
     
  6. Tim S

    Tim S Senior Member

    Location:
    East Tennessee
    I understand the second part of this statement, but can someone explain to me what is meant by "non-periodic components?"
     
  7. Gang-Twanger

    Gang-Twanger Forum Resident

    Transients are just one small part of it. SO many aspects to sound quality.

    In the past, it wasn't so easy for me to tell the difference between, say, 256kbps and 320kbps, or 16/44 versus 24/96 (Honestly, along with the mastering itself, which is extremely-important, I think the 24bit part is more-important than the 96khz, but that's just me). But nowadays, when it comes to digital audio (AUDIO, not recordings), I notice the difference to the point where I have stopped listening to anything below 320kbps. I used to listen to stuff that was like 128kbps, but not anymore. The difference in SQ is just too obvious, at least on my home system (When I'm elsewhere and just using my laptop or Kindle with my headphones [Grado RS2's], the difference isn't as obvious, which I think is more a result of using the laptop/Kindle as my "amp/source unit"... The headphones are certainly capable of better clarity, but I'm merely plugging them into my laptop or Kindle rather than my home system with the tube receiver, external DAC, etc, which would make the headphones much more-revealing).

    By the way, the tweeters in my main speakers start dipping around the 14khz mark (They're from 1963). Each speaker has two of them though, on the far-right & far-left. I can still hear the differences though, which are not all up in that inaudible range (Remember, our ears can only hear so much anyway, so don't get all-caught-up in that higher frequency stuff).
     
    Last edited: Oct 17, 2016
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  8. Gang-Twanger

    Gang-Twanger Forum Resident

    Or it could be both.

    Off-subject a bit, but I've never been a big fan of HDTracks. Not sure which mastering they use for any particular release, and for me, it all starts with that. Maybe someone can explain it to me a little better, but I find I have too many questions when it comes to their downloads.
     
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  9. David756

    David756 Active Member

    Location:
    Australia
    I look at the question pragmatically. In the days of analog, before 44.1/16 was even a thing, I didn't come across too many analog mediums from that era that could reproduce the kind of frequency response that 96kHz sampling can. A 1/4" half track tape machine at 15ips did little better than about 22kHz, if it was in excellent condition. So why is it an issue now, but never was then?
     
  10. missan

    missan Forum Resident

    Location:
    Stockholm
    If we want to reproduce a square-wave we need high frequences to be able to do so well. But it´s still so that we can look at the music as sines, so if higher sines isn´t there it doesn´t mean anything, as we can´t hear them anyway.

    As for if the 24/192 will sound better than 16/44,1; normally I really don´t want to spend much time finding out for sure, as it´s a lot of work. In my best moments, and not very scientific, I like 24/192 better.
     
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  11. chervokas

    chervokas Senior Member

    I pretty much agree with this. Whatever elements of musical sound exist above 20 kHz are so limited in quantity and importance -- what, a hair of the harmonics of a cymbal or highest piano notes or something, always at some tiny fraction of the amplitude of the fundamental, possibly not even recorded by the mics someone is using when making a recording and dying off quickly in space, possibly not being reproduced by our speakers, and almost certainly for most of us not being audible, and almost certainly not present on our most cherished recordings of the past made with mics that rolled off heavily and cut to vinyl with the high and low frequencies rolled?-- that if there's an audible difference between 44.1 sampling and higher rate sampling I'm inclined to believe it is NOT because of musical information above 20 kHz.

    Maybe it's because off the impact of commonly used sharp filtering at or above 20 kHz to deal with noise in the case of the lower sample rate, and some kind of impact that the filtering has on phase performance in the audible range or some such other artifact, which people have developed all kinds of workarounds and solutions for in 44.1 (so more than the musical information about 20 kHz maybe it's more about the 20 kHz ceiling's impact on frequencies below 20 kHz). Maybe there's something else in terms of having more samples per second and maybe as or more importantly, greater than 16-bit bit depth, that's a difference maker in terms of lower levels of quantization error, or some other sort of way in which having more samples per second results in some kind more realistic sense of the representation. Or maybe there's not much if any audible difference -- personally I have done such limited listening to higher sample rate and higher bit depth material, mostly in the context of portables or budget recording gear with midfi and studio headphones, that I can't say I've even tried to test high res in a truly resolving system. But musical information above 20 kHz? I doubt that's the difference maker, there just ain't very much of that if anything at any significant amplitude to matter that much.
     
  12. Drewan77

    Drewan77 Forum Resident

    Location:
    UK/USA
    I have a great system using open baffle speakers which measure to +/-3db 10hz-23khz in-room & transients can sound fabulous on the best recordings. Vocals, drums & acoustic guitar in particular often sound amazingly real & nothing I have heard handles transients like a good OB speaker.

    BUT....

    Music never manages the real attack of a live performance whenever there is a lot going on so I have to accept that listening at home is only a reproduction. I don't have the inclination or the time to worry about this, sample rates etc or conduct A-B listening.
     
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  13. Agitater

    Agitater Forum Resident

    Location:
    Toronto
    It's not always most certain that different master are used. But, I still think you're right. What I proposed was poor science, as far as truly accurate testing is concerned. For once though, for me personally, I did not have a science-based approach in mind. I was, instead, respecting what most music listeners have access to and what most music listeners will typically encounter when shopping for music in CD format and in high-res download format. The OP might as well compare what he reasonably can, then decide if the extra steps you outlined are important to him. In my view, if it turns out to be (for the OP) that only the sort of testing you outlined will tell the tale, then it sounds like a balance point the OP mentioned. That is, he already made it clear in his very first post that he was interested in hearing about the point at which determining differences because a chore.

    Irrespective of your point about how someone's DAC might handle different word length/bit-rate encodings in slightly different ways, that's the DAC the person actually owns. It's the DAC he's chosen to use for all his music listening. Basically, I think, the OP seems most interested in the best music listening experience he can reasonably expect from his existing equipment. To me, that means he only has to listen to what's available to him at retail stores, web sites and his own collection.
     
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  14. GuildX700

    GuildX700 Forum Resident

    Location:
    USA
    I have some speakers with Beryllium ribbon tweeters, they are flat out past 20kz and their down 3Db point is 40kz.

    There is something to be said for being able to reproduce past 20k, I'm not sure why, but there is.
     
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  15. Chooke

    Chooke Forum Resident

    Location:
    Perth, Australia
    +1
    A better test is to use Foobar with the ABX plugin and load your 24/96 or 24/192 file. This way not only is the mastering controlled, but so too are levels (they are matched) and it is double blind thus removing the human, and very well understood, expectation biases and placebo effects. Anything less is an invalid test.
     
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  16. Catcher10

    Catcher10 I like records, and Prog...duh

    I just press PLAY, if it sounds good then all is good. If someone has a "super-dooper" high end DAC and you press PLAY and you do not smile...well no clue what to tell you then.
     
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  17. Bryan T

    Bryan T Forum Resident

    Location:
    L.A.
    I buy light bulbs that extend into both infrared and ultraviolet, as it lets me see details that I wouldn't otherwise.
     
  18. Thermionic Vinyl

    Thermionic Vinyl Analogue Guru

    Location:
    Canada
    I can hear a difference in a (relatively) scientific double blind test. My friends and family can't.

    Pure analogue vs 192KHz PCM is noticeable...

    If you don't believe me then fly over here and I'll show you myself!
     
  19. Agitater

    Agitater Forum Resident

    Location:
    Toronto
    Hearing a difference between two things often isn't the final answer. It's whether or not the difference is merely another version of the same thing or, to your ears, a better version.
     
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  20. Thermionic Vinyl

    Thermionic Vinyl Analogue Guru

    Location:
    Canada
    In that respect, the final verdict with be purely subjective and dependent of the listener'a tastes.

    If we are trying to answer the OP's question, then I have evidence to suggest transients are more accurately reproduced when ultrasonics are present.
     
  21. Raylinds

    Raylinds Resident Lake Surfer

    I remember reading somewhere that having information above 20kHz makes a difference because, as those frequencies bounce around a room, they get lower in frequency and it is these reflections that can be heard and make a difference. I have no idea if that is true, but it seems plausible.
     
  22. konut

    konut Prodigious Member. Thank you.

    Location:
    Whatcom County, WA
    Preserving transients above 20khz is near the bottom of the list of important things to consider when enjoying the reproduction of music FOR ME. Heck, it isn't even on the list. There are so many other things of such far greater importance. When it comes to the enjoyment of digital medium, the quality of the analog output stage of one's DAC is the most important link in the chain.
     
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  23. Thermionic Vinyl

    Thermionic Vinyl Analogue Guru

    Location:
    Canada
    Mathematically speaking, the effects of ultrasonics should trickle down into the audible range. The harmonics change how we perceive how a fundemental tone sounds, would an ultrasonic harmonic have an audible effect? I'm not sure.
     
  24. Otlset

    Otlset I think I am I think

    Location:
    Temecula, CA
    It's the "Air".
     
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  25. Ephi82

    Ephi82 Still have two ears working

    Location:
    S FL
    Here is my opinion:

    It's very easy to hear the difference between vinyl and any form of digital recorded music. Vinyl has its own sound due to the way the recorded sound is reproduced, and the way the sound is shaped to be within the limits of the media. It can sound magnificent.

    I believe that the difference between 44.1, 96, and 192 recordings only matter in the production phase, in how fast digital processing is done in support of the digital recording process. There are numerous, well founded arguments that say 44.1 is all that is needed to support the limits of human hearing.

    I'll buy into the notion that 96khz might be superior for a very limited number of people, but 192 is pure snake oil in the finest tradition of audiophilia.....
     
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