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MLXXX

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About MLXXX

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  1. You truly do have an incredibly transparent A/D D/A processing unit then, as not to change the sound of the Holo R2R Spring dac once it goes through it, what brand and model is the A/D D/A unit??? @georgehifi, first off you seem to have jumped to a conclusion. The fact that one individual reports that A/D D/A processing has proven transparent for their ears doesn't imply that another person will necessarily find the processing transparent. And it certainly is no guarantee there won't be measurable differences. @georgehifi, secondly you seem to have relied on the conclusion you jumped to to say that a member of this forum is fooling himself, despite the fact that the member had very specifically said their claim was only in relation to their own hearing. Thirdly, even if A/D D/A conversion did actually make an audible difference (for some listeners, for some music, and under some conditions), one would need to consider how pronounced the difference was. For example is the difference so subtle as to only be noticeable with quick A B comparisons? Or is so dramatic that a person upon entering a room could declare with confidence, "You've obviously placed A/D D/A conversion into the signal path". Or, "You've obviously removed A/D D/A conversion from the signal path". Does the sonic signature of the original DAC remain audible, albeit altered slightly by the subsequent ADC - DAC processing? If that is so, is any great harm done? There's also the question whether a particular non-transparent ADC - DAC combination for a DSP crossover would in practice turn out to be a better compromise (provide a better audible result) than a particular passive crossover using imperfect real world components (capacitors, inductors, resistors).
  2. My understanding of DAC oversampling, for reconstruction purposes, of input at a sample rate of 44.1kHz, is that although the oversampling significantly alleviates the issue of filtering the upper frequencies that are theoretically audible and within coo-ee of 22.05kHz , it does not fully alleviate the issue, and as a result there is still scope for use of different filter slopes according to personal taste. I haven't rechecked that understanding before making this post. I might add that with an ADC that did an initial sampling at only 44.1kHz there would of course be the need for great care in filtering out any incoming signal components near 22.05kHz.
  3. Obviously. [Well as far I'm concerned it's obvious! Perhaps you are trying to educate others.] The fact remains that the CD player DAC has to reconstruct an audio signal which it receives as a stereo digital stream with a sample rate of only 44.1 kHz. This requires great attention to how the highest octave is filtered (despite whatever oversampling may be used by the DAC's internal processing). The problem is that the lower part of that highest octave for a sample rate of 44.1 kHz is well within the range of [typical, young adult] human hearing. But I'm sure you're aware of that! In contrast, an ADC for a speaker crossover function can be designed to do an initial sampling of the incoming analogue audio at a higher frequency (say 96 kHz). This means that incoming audio frequencies up to 22.05 kHz can be handled with ease when reconstructed later by a DAC. (There is no difficult issue with Nyquist image rejection for audible frequencies.) Earlier in this thread, @georgehifi referred to a DCS Vivaldi dac stack. This, like many other hi-end DAC implementations, allows the user to select alternative filtering:- Filters PCM mode: 4 filters give different trade-offs between the Nyquist image rejection and the phase response. 2 extra filters are available at 44.1, 176.4, 192, 352.8 and 384kS/s. Such choices can become quite significant (audible) where the incoming signal is at a sample rate of only 44.1 kHz. When I was younger I could hear effects of different filters for an oversampling DAC processing an incoming signal with a SR of 44.1 kHz. [I'm not sure I could hear such differences today!]
  4. If it imparted no sonic signature, wouldn't it be "cold and sterile"? [I note there are different solutions for a sample rate of 44.1kHz as regards how aggressively to filter the highest octave (where the frequency nears the Nyquist limit). In contrast to that, there is no need for ADCs and DACs for a DSP speaker crossover function to be limited to a sample rate of 44.1kHz. They can use higher sample rates and milder filtering.]
  5. If people "cherish" a particular DAC because it imparts a sonic signature they like, then they are free to use it to colour the sound (and avoid what they might consider cold and sterilized sound). [In a similar vein, people are free to use video settings on a television to make the picture colour warmer (more towards red) or colder (more towards blue). Or to provide a greater, or lesser, extent of colour saturation.] On an objective level, if seeking accurate rendition of the output of a cherished DAC, it would make sense to avoid a digital crossover if the digital crossover processing in contemplation could be expected to impart significantly more substantial artefacts than a passive crossover could be expected to impart to the cherished sound. And here I believe the traditional thinking of many 2-channel audiophiles is that a DAC is potentially an extremely lossy device, and any ADC would also potentially be a very lossy device, and it is accordingly "automatically" assumed that the conversions between analogue and digital with "ordinary" high quality circuitry (involving any ADCs and DACs) would necessarily have a highly deleterious effect on the cherished analogue signal. However given advances in ADC and DAC design and implementation, and the sample rates in use, it is more likely the ADCs and DACs will be transparent or near transparent, and will have negligible impact on the cherished sonic signature. This dichotomy in the audiophile world of insisting on perfection in some aspects of sound reproduction but embracing imperfection in other aspects is a recurring feature. It is evident in the desire by some to choose the high difficulty path of using a stylus tracking a rotating vinyl disc to acquire an audio signal that is not sterilized or cold. The imperfect signal thus acquired may then be put through a very expensive preamplifier, and then perhaps fed into an amplifier with outstanding good specifications for accuracy, such as the one cited at post #1. In the context I was referring to using DSP to perform a crossover function digitally rather than in the analogue domain (i.e. the same function as a passive crossover, nothing more complicated than that, but without the parasitic resistance and other imperfections of a passive crossover). I was not intending to refer to use of DSP beyond that.
  6. One can choose to listen to a sonic signature imparted by an exotic DAC [rather than the less coloured, closer to accurate, sound of a standard, high quality DAC] and refuse to allow relatively transparent (or even fully transparent) further processing. However It seems to me arbitrary, and ultimately inconsistent, to adopt a purist position for one link in the chain of reproduction and a non-purist position for another. If a sonic signature is imparted to an audible extent by an exotic DAC, why should one be concerned about inaudible, or barely audible, inaccuracies in subsequent processing? Such a position makes no sense to me unless perhaps one venerates the "audiophile glory" of the exotic DAC, and on that basis regards its output signal as sacrosanct. I suggest we need to move on from worshipping DACs.
  7. No, I'd envisage that the original intact CD digital stream would be subjected to an accurate, "pure", digital crossover, and then converted to analogue by readily available high quality DACs. In case you do not know this already, I regard the reverence accorded to very expensive, exotic, DACS in the 1980s and 1990s misplaced today. Digital to analogue conversion has become routine. I note this thread appears to have morphed into a free-for-all discussion about almost anything related to sound reproduction!
  8. That begs the question why use a DAC at all ahead of DSP. But anyway, no one was talking about a "lousy dac". Edit: other than yourself. I see you recently remarked: It is indeed an issue as to why people will use a CD player's DAC if intending to manipulate the signal digitally at a later point. They may "cherish" the DAC but it is introducing a conversion step that will need to be undone.
  9. I'm sorry @georgehifi but so many of your statements strike me as contradictory. There is no "purity" in a passive crossover, but there is (a certain extent of) imperfection. If a person wanted the closest approximation to true purity they'd go for DSP. But then you have also stated:- If you consider sterilized (i.e. accurate, uncoloured) sound "stark and uninteresting" then it appears you are not in actual fact pursuing "purity". Then you have expressed concern about "imperfection" in movement:of multiple drivers: You appear to jump between criticising even small departures from perfection (e.g. whether the movement of multiple units of the same model driver are in unison), but then bemoaning perfection (e.g. criticising a digital crossover for being stark and uninteresting). There appears to be no way to please you! ____ I recently had the privilege of attending a series of chamber music concerts, performed by professional musicians, on Nth Stradbroke Island (near Brisbane). On many occasions I wondered to myself how I'd assess the sound quality if what I was hearing wasn't live but was reproduced on a hi-fi setup. The experience served as a reminder to me that live music from acoustic instruments does not "sizzle" in the treble, or overwhelmingly thunder in the bass. Also it doesn't necessarily have a highly specific sound stage delineation of the location of the different instruments (this partially being because a given seating location will receive a mix of direct and reflected sound). It may be quixotic to expect a hi-fi system to do more than reproduce sound faithfully. If you want it to add sizzle, and thunderous bass, and somehow produce a 3D impression of the location of the instruments, and also be "pure", you may be dreaming an impossible dream. I feel I should make an attempt to make this post relevant to the actual thread topic! Here goes. Although there are some types of music that may require extremely high peaks of sound pressure level to reproduce the music realistically, much doesn't. Chamber music certainly doesn't. On the other hand, a full symphony orchestra, for certain pieces of music, can. So I would have to ask, for the size of auditorium typically available in the home and even with relatively insensitive speakers, would the power output of the amplifier referred to at post #1 actually be useful? Or would it be overkill, and go to waste? Are there any circumstances for home use where it would actually be useful to have so much power available?
  10. I think @georgehifi that your above statement is what set the cat amongst the pigeons. Anyway it's probably time for the thread to move on! Yes, although the amp described at post #1 is extremely powerful, and has a very low output impedance, it would not be able to correct the sound generated by a poor quality speaker system. It merely feeds the speaker system accurately. (Room correction, for example with Audyssey, would be another matter.) I could imagine the amp at post #1 being suitable for a larger room than would normally be found in a suburban home.
  11. Well they comply with the colour standards to a close approximation (no less so than projectors). Interestingly, the colour of movies transferred to Blu-ray discs will often have a colour cast in different scenes, designed to provide atmosphere (e.g. to create the impression of bleakness). What I suspect you may primarily be reacting to is screen size. A small screen will not look realistic for distant scenes because we need to converge our eyes (swivel our eyeballs inwards) to see detail on a 55" TV screen clearly; whereas in real life we can relax our eyes (leave their line of sight aligned parallel) to view detail in a distant scene.
  12. This shot of a kitchen is a good illustration of the picture clarity available in the 4K format. Mind you, a resolution format even less than 1080p can be satisfying to watch. (On Netflix you get titles in a broad range of formats: older ones in 480p, many in 1080p, and a sprinking of titles in 2160p. I find 480p quite watchable; it's just that 1080p is better, and 2160p better again.) I would be on the lookout for a projector than can do 2D in 4K (faux 4K acceptable); and that can do 3D with a left-right alternation rate of at least 144Hz, with low cross-talk, and good black levels. (This is a tall order because although DLP projectors exist with low 3D crosstalk, their black levels tend to be poor.)
  13. I don't what model Hisense set you purchased but they are one of the cheapest brands. In the past I have glanced at Hisense TVs in showrooms and been less than impressed. Samsung and Sony are brands more likely to yield good PQ.
  14. Yes, it's quite entertaining* how the Stereophile magazine editor was able to talk up something as ordinary as connecting to a different power point circuit: The sonic effect was nothing short of stunning. Within the context of a power amplifier’s characteristic sound quality, bass fundamentals relatively dropped away to minus infinity, such was the increase in their weight, while the WATT/Puppy’s “hump” in the upper bass became considerably less bothersome. Yes, the characteristic sounds of components were not changed-black was not rendered white-but the differences between those characters was heightened, the overall quality of each enhanced. The sonic contrast knob was turned up a notch, if you will, the blacks becoming a deeper black, the whites becoming more brilliant. ______ * Though on a more serious level, disturbing.
  15. MLXXX

    Trump

    It's good to see someone standing up against the petty and yet troubling decision to revoke the security clearance of a formerly high-ranking individual, simply because that individual had expressed [well-considered] criticism of the Trump Administration. From http://www.abc.net.au/news/2018-08-17/retired-admiral-william-mcraven-speaks-out-against-donald-trump/10131364 Retired US Navy admiral William McRaven praises John Brennan, says he won't be scared into silence by Donald Trump A retired US Navy admiral who oversaw the raid that killed Osama bin Laden has told Donald Trump he would be honoured if the 45th President would yank his security clearance just like he did to former CIA director John Brennan. In a letter to the President published in the Washington Post, retired Admiral William McRaven, calling Mr Brennan "one of the finest public servants I have ever known". "I would consider it an honor if you would revoke my security clearance as well, so I can add my name to the list of men and women who have spoken up against your presidency," ret-Admiral McRaven said. His name was not on Mr Trump's list. "Through your actions, you have embarrassed us in the eyes of our children, humiliated us on the world stage and, worst of all, divided us as a nation," wrote ret-Admiral McRaven, who led the US Joint Special Operations Command from 2011 to 2014. He said few Americans had done more than Mr Brennan to protect the nation. "He is a man of unparalleled integrity, whose honesty and character have never been in question … except by those who don't know him," he wrote.
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