Popular Post Archimago Posted January 2, 2018 Popular Post Share Posted January 2, 2018 On 12/31/2017 at 12:10 AM, GUTB said: I'm not going to buy the AES paper, so I'll go by the JAS paper which is freely available. Bob Stuart and Keith Howard cite studies showing the ability of human brains to activate at ultrasonic information at certain levels, a study showing ultrasonic information from real instruments linked to their perception in humans, a study showing audibility of the time-domain effects of certain digital filters, studies showing human listeners beating Fourier limitations. Stuart claims that human time-domain perception is much more acute than frequency-domain perception, and couches this in an evolutionary theory. None of these studies are mentioned by the presenter. GUTB: The AES paper is freely available here: http://www.aes.org/e-lib/browse.cfm?elib=17501 If the basis of MQA's research into human perceptibility are those articles Stuart cites and is presented as the foundation to what they're trying to achieve, then clearly this is all nonsense. Tell me, have you looked into those references? Do you believe any of those references actually apply to real music? How many of the references actually deal with humans (especially in the AES paper) as opposed to auditory perception of gerbils and owls (as the presenter alluded to)? Quote Presenter moves on to attacking sound quality claims made by MQA: Study of listeners showed no preference, citing Archimago's test. I've talked about Achimago's test before, and it's baldly obvious FUD hobby horse campaign of his. This was a test in which listeners without MQA DACs were used to determine the efficacy of MQA and other elements I won't go into here. How many times do I have to explain to you that the listening test involved actual music decoded by an actual licensed MQA software decoder (Audirvana+) and that I modeled the MQA digital playback filter based on what we know of the Dragonfly Black and Mytek Brooklyn? Do you not understand that in truth there is nothing all that remarkable about an "actual" MQA DAC that cannot be simulated already because at the end of the day, MQA playback is simply software decoding with a few digital filter parameters thrown in?! I know you like to be a proponent of MQA but in truth you never engage in discussion nor demonstrate a willingness to think about what you claim... Quote Other questions re: MQA filtering strategy based on his and Hotto's (CA's) opinions. I'm not equipped to address these opinions so I'll skip those. Seriously, unless you are able to address the issues about the crappy filtering used by MQA, you cannot refute the highly suboptimal filtering they've designed into the MQA firmware! Quote First presenter comes back and asks "where's the DRM?" Yes, thank you, let's please get into this... Presenter shows a diagram from the Hotto (ie, CA) paper. Hmm. Something's missing though... Oh right, the admission that this is just a guess based on the Bluesound code. But let's talk about this DRM. Where's the DRM? Still more re-hashed CA stuff...I'm going to skip these, I'm getting tired and I want to address the DRM already... Oh GOD we're doing this Utimaco thing again? This is the centerpiece of this entire "talk"?? Sigh...from the Utimaco website: To ensure the integrity of the artist’s music from the original source to the end listener, MQA needed a solution for securely signing the music file, to ensure cryptographically that what the listener hears is what the artist approved. Authentication is critical to MQA technology, which must work end-to-end, from the studio all the way to the music fan. An advanced cryptographic solution was the best option to verify the musical file. MQA turned to Utimaco, a leading manufacturer of hardware-based security solutions that provide the root of trust to keep cryptographic keys safe, secure critical digital infrastructures and authenticate high value data assets. There isn't a word about DRM. It's exactly what MQA has always said it was about, certifying that an MQA stream, is in fact, an MQA stream. It's what that blue light is all about: "you're getting the best experience from the studio, guaranteed, because this light says so". Is there an IP protection aspect to it -- probably! Who cares? Anyway, back to the presentation... There's nothing. Just a discussion on DRM. NOTHING on DRM on MQA. NOTHING. Why did I spend hours writing this post??? As the speaker says, MQA has a complex cryptographic scheme implemented. Sure, it doesn't prevent copying at this time. But it does implement "conditional access". And there are hints of the potential to implement "scrambling" in the firmware with bit transposition as the speaker mentioned. So the potential is there in the future if they wanted to implement something more impactful of playback quality. Why is this not DRM? Personally I don't particularly worry about DRM that much because MQA doesn't present a system truly capable of high fidelity compared to hi-res FLAC. I'd be more concerned if indeed MQA was a real step forward in terms of encoding higher fidelity and the access restriction prevented me from using a legally purchased album through DSP room correction at full resolution. Quote HAHAHA audience member asks a REALLY good question: "If MQA firmware has been reverse engineered, it seems it doesn't have such a sophisticated protection scheme..." WOW GOOD POINT. I don't see the dilemma here. Firmware can be downloaded and analyzed. Heck, even complex schemes like HDCP can be stripped from HDMI signals or cracked. The truth is that nobody's saying that MQA's encoding system has been figured out nor has anyone "cracked" MQA's crypto scheme to turn on that blue light. Even without doing all that, there's enough information looking under the hood for us to have a reasonable level of understanding and adjudicate for ourselves the areas that MQA appear to be lacking... crenca, Shadders, semente and 6 others 6 1 2 Archimago's Musings: A "more objective" take for the Rational Audiophile. Beyond mere fidelity, into immersion and realism. R.I.P. MQA 2014-2023: Hyped product thanks to uneducated, uncritical advocates & captured press. Link to comment
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