What's an example of a "good DAC"?

Discussion in 'Sound Science' started by EnsisTheSlayer, Aug 30, 2017.

  1. gregorio
    Yes.
     
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  2. JaeYoon
  3. Whazzzup
    I like call waiting
     
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  4. bigshot
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  5. JaeYoon
    Someone in that thread believes our music studios are using subpar DACs and they should implement robb watts 1 million taps to make sound quality "better".

    :p what do you think of that! :joy:

    It's these sound engineers with their subpar run of the mill dacs with their modern digital processing ruining mah music!!! /s
     
  6. amirm
    I attended the talk. He is very much right about the ringing bit. Alas, after that part it went downhill fast. When RMAF posts the video, you will see my questions at the end.

    With him being a sponsor here, I don't dare saying much. :) But plan to post in ASR Forum now that the slides are public. For now, he does no controlled listening of his work. And by any objective measure, his work is beyond roundoff errors of audio samples.
     
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  7. JaeYoon
    I will check there.
     
  8. pinnahertz
    They look like slick marketing hype. The sweeping generalizations erode any shred of authenticity to zero.
     
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  9. gregorio
    As ever, a smattering of truth mixed with confusion of scale, misrepresentation and outright lies/nonsense!

    Slide 1 & 2: Are roughly correct but the 10% figure is an educated scientific guess.
    Slide 3: Each sound is not separated out by the brain, just certain sounds, to a certain degree, depending on what we're concentrating on. For example, with an orchestra, the brain does not separate out the sound of each individual violin, just the violin section/s. And, there is an amount of precision locating the sound in 3D space but it's fairly limited.
    Slide 4: 1. He's contradicting himself; we obviously have some idea of how the brain processes the ear's data. If we had no understanding, then his assertion of 10% of the data used by the brain (and other assertions) MUST be a lie that he's just made-up. 2. We don't make blind assumptions, we make educated assumptions. If, for example, some digital artefact is 100,000 times lower than the lowest level anyone has has ever reliably demonstrated the ability to detect, then it's a safe assumption that artefact is inaudible. 3. Duh, threshold of audibility tests are obviously designed to test the threshold of audibility, not how the brain works, that's why they're called threshold of audibility tests! 4. Thank god! Sound quality is an individual's personal subjective judgement/opinion, whereas accuracy is a "simple technical performance". This is of course why SQ rather than accuracy/fidelity is used as the reference by so many audiophile equipment manufacturers. It allows them to make pretty much any claim they want, regardless of how ridiculous, because they can always say: "Well, that's my (or our engineers, shills, etc.) opinion"!
    Slide 5: 1. The importance of transients varies, from little/no importance to somewhat important. 2&3. I don't know if this is right or wrong, his wording is vague. 4. The brain calculates position in the horizontal/lateral plane to about 1 degree of accuracy and in the vertical plane to about 7 degrees. 5. Not "extraordinary" precision. 6. The sampling interval does NOT define timing accuracy. This is an old, debunked audiophile myth.
    Slide 6: 1. Perception of bass pitch is not poor, in fact it's good, he's ignoring the fact that each octave doubles frequency. An octave above say 60Hz is 120Hz, the entire octave fits within a 60Hz range. An octave above 1,000Hz is 2,000Hz, an octave now occupies a 1,000Hz range. 2. Nonsense, the transient is generally the least important attribute of note production for determining pitch. 3. Nonsense, remove the transient and pitch is still easily detectable, this is a simple test to do, one Rob Watts obviously hasn't even tried, or has tried and is simply lying.
    Slide 7: 1. Nonsense, timbre depends on the harmonics produced and their relative balance. Transients are only a part of the picture and often the least important part. 2. Either Rob Watts has a severe hearing impairment, he's lying or both.
    Slide 8: I can't find a single point on this page which is true! At best, some of the point's are partially true. For example, the timing resolution of CD being 22 micro-secs is a lie! 22 micro-secs is the duration between samples, but as even he states "the interpolation filter reconstructs the missing bits between samples". The result is that timing accuracy off 44.1 is almost infinite, roughly 100,000 times below the 4 micro-secs he claims the ear/brain can resolve! AND, stereo imaging/positioning inaccuracies due to timing error between left and right channels does not exist at all. Timing accuracy between channels is perfect at 44.1, there is zero relative shift!
    Slide 9 ...: I can't be bothered to go through point by point for the rest of the slides, the main points are:
    1. A continued reliance on the myth of timing inaccuracy with CD.
    2. Everybody has not said that pre-ringing is bad, just some in the audiophile community. Pretty much everyone else has said that pre-ringing is inaudible with musical material.
    3. Congrats for working out a Dirac impulse is an illegal signal which does not exist in the real world.
    4. More congrats to Rob Watts for inventing the linear-phase FIR filter ... Shame it was already invented decades ago!
    5. Someone with more intimate knowledge of filter implementation than me needs to debunk the rest of his assertions about filters but from what I know: The number of taps effectively defines the amount of attenuation of the stop-band signal (the signal beyond the Nyquist point). AFAIK, even standard $1.50 DAC chips can attain attenuation of the stop band for 44/16 to about -120dB. A 500 tap filter at 44.1 requires about 88 million computations per second per channel, a 1,000,000 tap filter @ 768kHz would require 16,000 times more computations per sec per channel, and for what benefit? In the first place, adding more taps can do more harm than good but even if the filter does maintain linearity while reducing alias images lower than the already achieved -120dB and/or reduces pre-ringing even further below inaudible levels, how is this of any benefit at all, except in terms of bigger numbers for marketing purposes?
    The "Mysteries" slide impressively manages to conflate the previous half truths and nonsense with complete lies about reverb, resulting in shockingly pure, 24 carat bullsh*t!! Lies about reverb: 1. Perceiving "the walls of the acoustic more easily" would in many/most cases be a bad thing. It would indicate a severe failure to accurately reproduce density and diffusion parameters and early reflection times and balance. 2. The RT60 of 1.4 secs is complete nonsense/a lie. The RT60 of cinema mix stages is specified at around 0.2 secs, the average music studio control room would be around 0.4-0.6secs, the average living room, about 0.4-1.0 secs, a symphony concert hall, between 2.0 and 4.0 secs, a cathedral much more, up to about 16 secs. These are real world RT60 times but in virtually all popular music genres there is very little or absolutely no real world reverb, the reverbs used are artificially generated and there are usually at least two very different reverbs used and sometimes 4 or more.
    The "futures" slide is again nonsense and to answer his question: If his M-scaling filter really does change the sound-stage then it's pretty seriously flawed and the "why" would be because Rob Watts either has no idea what he's doing or because he deliberately wants to sacrifice accuracy for the marketing benefit of bigger numbers!

    The level of "fake news" demonstrated here makes Donald Trump look like a rank amateur. Rob Watts for president!

    G
     
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  10. JaeYoon
    Someone has to be a serious shill in order to lie to people to make money :frowning2:

    Sadly this hobby is filled with people doing just this.

    I have a bad feeling Rob Watts is just one of them.
     
  11. bigshot
    I can tell you from experience that this is something to seriously consider.
     
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  12. jfvny
    i learn so much from these threads :)
     
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  13. pibroch
    Is there a history of posters being suspended for criticising a sponsors product?
     
  14. bigshot
    It's ancient history now thankfully.
     
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  15. JaeYoon
    So does that mean we can criticize sponser products today? :p
     

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