From: david.brown@hesbynett.no   
      
   On 08/09/2025 23:57, George Neuner wrote:   
   > On Mon, 8 Sep 2025 10:59:50 +0200, David Brown   
   >  wrote:   
   >   
   >> ... For people who say they can distinguish CD audio from   
   >> AAC or other high bps compressed audio, and other "golden ears"   
   >> distinctions, it's a different matter - in double-blind tests, most fail   
   >> badly.  There are a great many factors involved in high-quality audio   
   >> reproduction - the basic sample rate is only one of them.   
   >   
   > That's true, but the basic sample rate does make a significant   
   > difference.  I don't know if it is true, but I have read that to   
   > /accurately/ reproduce a given note requires 10 to 11 harmonics: the   
   > primary note, 7 higher, and 2 to 3 lower.   
      
   There you are talking about /timbre/, not just frequency.  It's the   
   harmonics that make the same note sound differently on a piano and a   
   violin.  But at the high frequency range, you can't distinguish these.   
   If you can hear sounds up to 16 kHz (which would be better than most   
   regulars in this group, with the demographics of males of a certain   
   age), you would not be able to able to determine if it is a piano note   
   or a violin note.  Musical instruments don't go anything like that high   
   - even a piccolo won't go over about 4 kHz.  Sounds about that range   
   have all the musical nuances of chalk on a blackboard.   
      
   High-pitch music or very high pitch singing usually tops out at about 2   
   Khz for the base frequency.  The tenth harmonic would then be at 20 kHz.   
     So the maths works out fine for 44.1 kHz sampling rate.   
      
   Of course there is the very significant matter of how the reproduced   
   44.1 kHz is filtered - it must, in an analogue filter, try to cut out   
   virtually everything of 22.5 kHz and above while allowing 20 kHz and   
   below to pass through with a flat power response and linear phase   
   response.  That does not happen in practice - and that is a key reason   
   why harmonics of higher pitched notes are usually poor from CD quality   
   music, especially on low-end audio systems.  (High-end audio systems   
   up-sample the 44.1 kHz / 16-bit to perhaps 192 kHz / 24-bit, so that the   
   filtering is vastly better).   
      
   >   
   > This means most notes will include sounds that are outside the range   
   > of (normal) human hearing, but you can still /feel/ these sounds [even   
   > the high ones] and miss them when they are absent.   
   >   
      
   Nope.  Most notes are much lower, and harmonics of relevance are within   
   the range of human hearing.  For high enough notes, you simply don't   
   hear as much harmonic information.   
      
   >   
   > C8 (high C) on the piano is ~4186 Hz.  Assuming the need for the 7th   
   > higher harmonic - 29302 Hz - Nyquist would demand a minimum sampling   
   > rate of 58604/s to accurately reproduce C8.   
   >   
      
   You can't accurately hear C8 even when live - you don't get the same   
   harmonic information as you do with C6, because your ears can't   
   distinguish the higher harmonics.  Your ears have the same limitations   
   as any other senses in this manner - you can look at your cat's feet and   
   count its toes, but if you look at a fly's feet you can't count the toes.   
      
   >   
   > In practice, unless you like orchestral, or certain folk or country,   
   > you are not likely to hear much difference between a CD and a decent   
   > quality compressed version of it.  But the CD itself is not a faithful   
   > reproduction of the live performance.   
   >   
      
   Good quality compressed formats are often better than CD quality.  The   
   killer for CD quality is not the sample rate, it is the limited dynamic   
   range from the linear 16-bit range.  Compressed formats will, in effect,   
   use a more logarithmic scale (like A-law and mu-law, used to get   
   comprehensible speech despite a much smaller sample size) that is more   
   in line with the way the human brain interprets sound.   
      
   > And, of course, if you like orchestral you are more likely to be   
   > listening to vinyl rather than CD.  8-)   
      
   In theory (but very rarely in practice), when combined with good enough   
   amplifiers and speakers, vinyl has a a higher dynamic range than CD   
   audio.  But that is only the case when the record is new.  Play it a few   
   times, and the wear from the needle will smooth out the tracks enough to   
   eliminate the difference.   
      
   But enjoying music is a psychologically, physically, mentally and   
   biologically complex hobby.  The comfort of the chair you are sitting   
   in, or the type of reflections and absorptions from the rest of the   
   room, can make a big difference.  Knowing that you have spent a great   
   deal of money on your impressive-looking hifi system will improve your   
   listening experience regardless of what any audio measurement might say.   
     Some audiophiles prefer the "valve sound" over "transistor sound" -   
   not because the sound reproduction is more accurate (it is not - valves   
   add second harmonic distortion that is non-existent in transistor   
   amplifiers), but simply because they like it better.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)