sandyk Posted October 12, 2017 Share Posted October 12, 2017 39 minutes ago, esldude said: Some dbt's are suspect. Sighted uncontrolled evaluations are always suspect. Yes. How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
fas42 Posted October 12, 2017 Share Posted October 12, 2017 9 hours ago, pkane2001 said: Sure, I can envision all these noise paths through the system. But, the result of these should be measurable. What is reported, instead, is that they are audible, but not measurable. That is a big red flag for me. If noise we are fighting has an effect below the measurable noise floor of the whole system, and well below audibility, then what do these cleaner devices really do? The impact is measurable, but is hard to do. It's not a noise floor in the conventional sense, but distortion artifacts in the sound, which are audible; those distortion behaviours are frequently transitory, highly dependent on the instantaneous state of part of the system - as an example of how complexities of interactions play their part, consider conventional feedback in a power amplifier; this may work beautifully in theory, in the design, but then throw in non-ideal voltage rails into the equation, say - how the real world works, IOW - and it falls apart. I've done exercises simulating what happens in circuits which are much, much closer to everything being real world, rather than living in a black box perfect environment - and under 'stress' misbehaviour is rife; parts of the circuit no longer behave as they should, the internals are momentarily in a state of chaos, from which the circuit has to recover - conventional, static measuring never detects this sort of faulty operation. The noise, misbehaviour is not below audibility - that's why 'difficult' recordings sound unpleasant on less capable systems: the signal is of a type that 'stresses' the circuitry, misbehaviour is of a high order - and the impact is obvious in the observed sound. If one is familiar with how such a recording comes across with competent playback then it is trivial to discern when an audio system is faulty. If these "cleaning devices" change the perceived sound with 'awkward' recordings then they are doing something - whether they are making things better, or worse, is then another matter to determine. Link to comment
Popular Post fas42 Posted October 12, 2017 Popular Post Share Posted October 12, 2017 I currently have on hand a perfect example of where "bias" rears its ugly head - and it's a huge pain to get under control : I'm experimenting with decompressing a piece of music posted by sandyk, and listening for the optimum settings. What happens is that the more I listen to it, the more I "know" this piece, and my brain automatically compensates for a lower quality version - it ends up "always sounding the same" !! This is when a variation in technique is needed - just focus on some tiny part of the whole which is too small to trigger the musical connection; or go away and forget about it for a while, come back with refreshed ears ... lucretius and Teresa 1 1 Link to comment
pkane2001 Posted October 12, 2017 Share Posted October 12, 2017 18 minutes ago, fas42 said: The impact is measurable, but is hard to do. Would love to see a single measurement, no matter how complex, that demonstrates the effect you're describing. -Paul DeltaWave, DISTORT, Earful, PKHarmonic, new: Multitone Analyzer Link to comment
mansr Posted October 12, 2017 Share Posted October 12, 2017 30 minutes ago, fas42 said: The noise, misbehaviour is not below audibility - that's why 'difficult' recordings sound unpleasant on less capable systems: the signal is of a type that 'stresses' the circuitry, misbehaviour is of a high order - and the impact is obvious in the observed sound. If one is familiar with how such a recording comes across with competent playback then it is trivial to discern when an audio system is faulty. So devise a test signal that "stresses" the system to an extreme extent. Link to comment
fas42 Posted October 12, 2017 Share Posted October 12, 2017 29 minutes ago, pkane2001 said: Would love to see a single measurement, no matter how complex, that demonstrates the effect you're describing. I have never played with USB audio, hence any USB "fixing" tweaks - my focus a lot of the time has been on the quality of connections in a system, which can have a strong degrading impact on SQ; RCA parts are the work of the devil! Now, I have no problem hearing the debilitating effect of these - they add a level of "dirtiness" to the sound, like a layer of dust on a pane of glass ... but how to measure the precise degradation in the sound? I would be hard pressed to think of a simple approach. Teresa 1 Link to comment
Popular Post jabbr Posted October 12, 2017 Popular Post Share Posted October 12, 2017 Food for thought: https://www.amphenolrf.com/media/pdf/White Papers/Passive Intermodulation Distortion.pdf lucretius and Teresa 1 1 Custom room treatments for headphone users. Link to comment
Ralf11 Posted October 12, 2017 Share Posted October 12, 2017 22 minutes ago, fas42 said: ... the more I listen to it, the more I "know" this piece, and my brain automatically compensates ... this is a well-documented sensory phenomenon, and likely accounts for any changes due to to 'burn-in' of a USB cable, besides a lot of other so-called burn-in effects (not sayin' there is no electronic or physical basis for burn-in, esp. when listening to Johnny Cash) Link to comment
fas42 Posted October 12, 2017 Share Posted October 12, 2017 16 minutes ago, mansr said: So devise a test signal that "stresses" the system to an extreme extent. In one sense I have - recordings that only have nominal levels of compression applied, but are very "dense" in the sense of the average level of the signal; which then also have a clean, high treble component as part of the mix. The perfect candidate for this are classic Status Quo tracks: constantly driving, boogie guitar core, with a drum kit where the cymbals are in action throughout; the quality of the cymbal sound is an instant giveaway of where the rig is at ... So, mimic the mix of these tracks, with the treble layer being the test indicator - and measure the attributes of that treble content under various conditions. Link to comment
Popular Post Teresa Posted October 12, 2017 Popular Post Share Posted October 12, 2017 1 hour ago, pkane2001 said: You can argue against DBTs all you want, but if DBTs are biased then how could a sighted test be any more valid? That's why I don't trust either one; DBTs or other peoples sighted listening impressions. If something looks interesting I have to hear it for myself, not just to see if there is a difference (for me) but if the difference makes my music sound more or less realistic. If enough people rave about something and I have interest I might try it if I get a money-back satisfaction guarantee. Most DBTs fail to show any statistical differences between most everything, and the few that do, only show a very small statistical difference. Thus I put zero stock in DBTs. On the other hand long-term listening lets me hear any accumulative effects on sound quality that increase over time. Things such as listening fatigue, if string tone is strident or smooth, if the overall sound is cold or warm, etc. The nasty sounding stuff in recordings and audio equipment sometimes takes weeks to experience in their totality. They start off as sounding fine, then progress to slightly wrong, then to slightly irritating, then more irritating and finally unlistenable. And this differs from person to person. So no one can listen for me, I must listen for myself. 1 hour ago, pkane2001 said: Nah. I know this from personal experience How is that even possible? Allan F and Audiophile Neuroscience 1 1 I have dementia. I save all my posts in a text file I call Forums. I do a search in that file to find out what I said or did in the past. I still love music. Teresa Link to comment
Allan F Posted October 12, 2017 Share Posted October 12, 2017 1 hour ago, pkane2001 said: Nah. I know this from personal experience I have no reason to question your experience. But, it runs counter to the experience of every audiophile I know. "Relax, it's only hi-fi. There's never been a hi-fi emergency." - Roy Hall "Not everything that can be counted counts, and not everything that counts can be counted." - William Bruce Cameron Link to comment
fas42 Posted October 12, 2017 Share Posted October 12, 2017 7 minutes ago, Teresa said: ... . The nasty sounding stuff in recordings and audio equipment sometimes takes weeks to experience in their totality. They start off as sounding fine, then progress to slightly wrong, then to slightly irritating, then more irritating and finally unlistenable. And this differs from person to person. So no one can listen for me, I must listen for myself. The good news is, that "nasty sounding stuff" exists in audio equipment, rather than recordings. The better the playback becomes, the fewer the number of recordings that have "nasty sounding" remnants - this will most likely still depend on the individual to some degree, but IME the number can be reduced to zero. It may seem strange that this is possible - because similar electronic circuits were in operation during the recording - but to me it seems that the particularly irritating aspects occur because the brain is trying to cope with the two quite separate layers of distortion: that of the recording, which are then compounded by that of the playback. Link to comment
Popular Post Allan F Posted October 12, 2017 Popular Post Share Posted October 12, 2017 16 minutes ago, fas42 said: The good news is, that "nasty sounding stuff" exists in audio equipment, rather than recordings. It is not uncommon to find "the nasty sounding stuff" in the recording. And when that is the case, the more transparent and resolving the system, the worse it often sounds. Audiophile Neuroscience and Teresa 2 "Relax, it's only hi-fi. There's never been a hi-fi emergency." - Roy Hall "Not everything that can be counted counts, and not everything that counts can be counted." - William Bruce Cameron Link to comment
Allan F Posted October 12, 2017 Share Posted October 12, 2017 Sorry, duplicate post. "Relax, it's only hi-fi. There's never been a hi-fi emergency." - Roy Hall "Not everything that can be counted counts, and not everything that counts can be counted." - William Bruce Cameron Link to comment
mansr Posted October 13, 2017 Share Posted October 13, 2017 20 minutes ago, Allan F said: I have no reason to question your experience. But, it runs counter to the experience of every audiophile I know. Obviously. That's the definition of an audiophile. Link to comment
fas42 Posted October 13, 2017 Share Posted October 13, 2017 Just now, Allan F said: That's a giant leap. It is not uncommon to find "the nasty sounding stuff" in the recording. And, often, the more transparent and resolving the system, the worse it sounds. IME, there is an "audiophile hump" in the listening experience - of unpleasantness. Below that peak negative one is not hearing enough, in general, to think that badly of the recording; at the worst point of the hump every possible irksome trigger in the recording is, errr ..., triggering - but go the next step of refinement of the playback, and all the triggers stop happening. All the detail is heard, but it all makes sense - you finally understand how the recording was put together, in the minutest details, but uppermost the 'musicality' of the event captured comes through - subjectively, it overrides any little niggles one may have with the recording as a technical exercise. I have gone through that hump 100's, if not 1,000's of times - it's a classic "no pain, no gain" type of thing ... Link to comment
sandyk Posted October 13, 2017 Share Posted October 13, 2017 1 hour ago, mansr said: So devise a test signal that "stresses" the system to an extreme extent. Record SWMBO screaming at you after you have made a mess! How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
jabbr Posted October 13, 2017 Share Posted October 13, 2017 John Curl has written extensively about measurable differences between resistors. http://www.diyaudio.com/forums/the-lounge/146693-john-curls-blowtorch-preamplifier-ii-634.html Teresa 1 Custom room treatments for headphone users. Link to comment
Allan F Posted October 13, 2017 Share Posted October 13, 2017 38 minutes ago, jabbr said: John Curl has written extensively about measurable differences between resistors. http://www.diyaudio.com/forums/the-lounge/146693-john-curls-blowtorch-preamplifier-ii-634.html Apart from demonstrating his expertise, that doesn't run contrary to his expressed experience in finding that certain resistors did not sound the same, notwithstanding that there was no measurable difference between them. Teresa 1 "Relax, it's only hi-fi. There's never been a hi-fi emergency." - Roy Hall "Not everything that can be counted counts, and not everything that counts can be counted." - William Bruce Cameron Link to comment
fas42 Posted October 13, 2017 Share Posted October 13, 2017 1 hour ago, jabbr said: Food for thought: https://www.amphenolrf.com/media/pdf/White Papers/Passive Intermodulation Distortion.pdf Excellent link. From it, Quote Causes: As stated earlier, in the general sense, non - linear mixing causes the generation of PIM (Passive Intermodulation Distortion). Specifically, there are 3 major causes of PIM in passive devices: 1. Poor contact junctions 2. Components made with, or plated with materials that exhibit some level of hysteresis 3. Contamination Contact nonlinearities occur when a current carrying contact zone becomes separated. This usually occurs on a microscopic level and can be due to insufficient contact pressure, irregular contact surfaces, o xidation causing a metal/oxide junction, contact impurities or corrosion. This contact surfaces can generate a voltage potential barrier, where electron tunneling (known as the diode effect) or microscopic arcing may take place resulti ng in a nonlinear voltage to current ratio. This sounds right on the money ... I've been fighting this, or variants of it for 30 years ... Link to comment
jabbr Posted October 13, 2017 Share Posted October 13, 2017 1 minute ago, fas42 said: This sounds right on the money ... I've been fighting this, or variants of it for 30 years ... That was for you Custom room treatments for headphone users. Link to comment
jabbr Posted October 13, 2017 Share Posted October 13, 2017 16 minutes ago, Allan F said: So? That doesn't run contrary to his expressed experience in finding that certain resistors did not sound the same, notwithstanding that there was no measurable difference between them. Without knowing exactly which measurements were done, impossible to evaluate your memory of what he said. No two resistors measure the same at some detail of measurement. Custom room treatments for headphone users. Link to comment
Allan F Posted October 13, 2017 Share Posted October 13, 2017 35 minutes ago, jabbr said: Without knowing exactly which measurements were done, impossible to evaluate your memory of what he said. Frankly, your evaluation of my memory of what he said is of absolutely no significance. I was there; you weren't. When the seminar - The Four Wise Men of Design - from RMAF 2017 is posted online, you can listen to what he said and draw whatever conclusions that you wish. He did not refer to any specific measurements. He only said that they measured the same. "Relax, it's only hi-fi. There's never been a hi-fi emergency." - Roy Hall "Not everything that can be counted counts, and not everything that counts can be counted." - William Bruce Cameron Link to comment
fas42 Posted October 13, 2017 Share Posted October 13, 2017 7 minutes ago, jabbr said: That was for you Interesting how audiophiles have a keen sense for what's important - thread after thread, 1,000s of posts about the subtleties of PIM behaviour - yet the vitally important topic of MQA is completely ignored, treated as if it were irrelevant ... jabbr 1 Link to comment
jabbr Posted October 13, 2017 Share Posted October 13, 2017 1 minute ago, Allan F said: Frankly, your evaluation of my memory of what he said is of absolutely no significance. I was there; you weren't. When the seminar, The Four Wise Men of Design, from RMAF 2017 is posted online you can listen to what he said and draw whatever conclusions you wish. He did not refer to any specific measurements. Speaking of PIM, here: he discusses the need to develop new type of measurements to improve his new designs: http://www.diyaudio.com/forums/the-lounge/146693-john-curls-blowtorch-preamplifier-ii-9538.html#post5164494 Custom room treatments for headphone users. Link to comment
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