[ProAudio] [ProAud] The High-Resolution Challenge

Dan Lavry dan at lavryengineering.com
Thu Feb 13 12:23:24 EST 2020

Increasing the bandwidth comes with increased noise. It is true for converters, analog amplifiers and every thing.Assuming the simple case of random flat noise, doubling the bandwidth increase noise by near 3dB. The argument is that you don't hear the noise above hearing (say above 20Khz), so why care?Let's look at harmonics, and at noise picked up on analog cables. Let's focus on the energy above hearing. Can that cause a probem? Not an issue when rhe device processing the signal (DA, power amp, speaker...) is perfecty linear. But non linearity makes some of that high frequency energy find its way to the hearing range (intermodulation generates sums, differences with integer multiples...).How big a problem is it? I live it up to the good well trained ears. Personaly, I think it would be dumb to consider 1Ghz bandwidth for audio. The old hifi standard was 20-20Khz. I see a couple of reasons to stay away from excessive bandwith, but cutting it short, at 96KHz  sampling, you have around 20Khz audio and 20-28Khz region that you wish to have little energy, to overcome possible audible non linearity of the next devices. At 192Khz sampling, you have 60-70KHz of un needed bandwith...The main reason why people don't encounter much of what I described is most mics provide a lot protection.  20KHz mic will make sure that energy will be removed from the above hearing zone (before encountering non linearity). So why 192Khz or higher? If you can't hear it, and your dog can't either...RegardsDan LavrySent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Chuck Zwicky via ProAudio <proaudio at bach.pgm.com> 
Date: 2/12/20  8:24 AM  (GMT-08:00) 
To: Bob Katz <bobkatz at digido.com>, proaudio at bach.pgm.com 
Subject: Re: [ProAudio] [ProAud] The High-Resolution Challenge 

On Feb 11, 2020, at 13:28, Bob Katz via ProAudio <proaudio at bach.pgm.com> wrote: J. R. Stuart and P. G. Craven, “The Gentle Art of Dithering” J. Audio Eng. Soc., vol. 67, no. 5, pp. 278–299, (2019 May.). DOI: https://doi.org/10.17743/jaes.2019.0011he points out on page 290 the number of decimators and upsampling filters that occur in typical chip-based converters. And that these stages are not dithered. And that there are fewer of these stages when the converters are used at a higher sample rate. Smoking gun.... BKIf you look at the specs for converter chips themselves, you will see that the noise and distortion figures are higher when used at the multiple rates (88.2, 96, 176.4, 192) than they are at 44.1 or 48kHz“Smoking gun" indeed.-CZ

    On 2/11/20 1:28 AM, James Johnston via
      ProAudio wrote:
        I must say that I am sorely tempted to see if I can get
          somebody to whip up an app that measures effective bandwidth
          of a PCM track at any common sampling rate.
        On Mon, Feb 10, 2020 at 10:15
          PM mark whitehouse via ProAudio <proaudio at bach.pgm.com>
          Following on from our discussion of around 18
            months ago,
            I know in Australia there were moves to get some kind
              of "truth in marketing" 
            in regards to High sample rate recordings.
            And promoting the differences in standards that are now
            Essentially a standard that could be understood by and
              promoted to consumers, musicians etc.
            It doesnt seem to have gone far and when you see things
              like this
            It makes you wonder if things will improve.
            Is there any consensus on getting this acknowledged? 
                                  To upload files to our server,
                                    Please click the following link and
                                    follow the steps on the Hightail
                                    page. https://spaces.hightail.com/uplink/ProCopy-Data
                                  Pro-Copy - Promote Media Group 
                                  Unit 2  39 Enterprise Crescent 
                                  PH +61 (08) 9375 3902 
                                  AustWide: 1300 4
                                  general enquiries email - info at procopy.com.au
                              This transmission is confidential. This
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://bach.pgm.com/pipermail/proaudio/attachments/20200213/68a44e21/attachment.html>

More information about the ProAudio mailing list