Saturday, 26 November 2022

"High End" Audiophile Science? On Milind N. Kunchur's hard-to-believe research articles.

It has been a busy week so let's keep this article somewhat shorter. ;-)

Beyond the typical audiophile magazines, websites, and videos, I think it's interesting once awhile to think about some of the research out there in the academic literature related to "audiophile" topics.

As I have said many times, I believe that typical 2-channel hi-fi audio is very much a "mature" science these days so on balance it's probably unlikely that understanding of core technologies should be too contentious. I know, some audiophiles and companies will protest this idea with the belief that human hearing somehow has much more potential and that we cannot measure all domains of auditory acuity as applied to our audio tech. As science-driven hobbyists, since we can perform blind tests and show that people have difficulty differentiating high bitrate MP3 from lossless, even relatively high distortions are difficult to hear, and hi-res audio is generally indistinguishable from 16/44.1 lossless (except for a few minor instances which can be statistically significant but practically not likely relevant for music listening), I think the onus of proof remains on those who make contentious or dramatic claims outside of the standard paradigm.

And so it is that in this blog over the years we've discussed some odd research from Dr. Milind N. Kunchur from the University of South Carolina in the Physics and Astronomy department (here's his website). Have a look at this video from a year ago to get a sense of some of his thinking on "High End Audio":


That first part suggesting time delay audibility is interesting but says little about absolute temporal resolution of the human ear/mind system (which he claims to be about 5μs later on around 13:00). And it's no surprise that reversing the playback of a piano note resulted in a different sound (7:30); haven't we known for decades that playing rock'n'roll in reverse also sounds satanic? ;-)

16:00 is where things get kind of interesting. First it's not technically correct that the ear has a dynamic range of 120dB when listening to music. Yes, it can accommodate a 120dB range, but the neurons have more like 20-40dB range at any one time, with adaptive processing down the auditory pathway from the periphery (eg. tensor tympani and stapedius muscles) into the midbrain (see this paper). Like pupillary constriction or dilatation to adapt to visual brightness; at any one time we can maybe perceive an excellent 10-14 stops, but given more time to adapt, our eyes can perceive up to 21 f-stops darkest to brightest! So getting all excited about just a big number like 120dB, while potentially true if the subject doesn't go deaf with the loudest levels, is a bit "hypish" without recognizing practical limits and context (important when presenting scientific evidence). He uses this as justification of why we have not reached a place of "diminishing returns" with expensive devices. Clearly dynamic range is but just one parameter why he "personally (has) never heard an audio system which 100% convinced me there's a grand piano playing in front of me" (17:00), and not necessarily the most important.
[Note interesting comment by Cin below. Comments about hearing dynamic range >60dB with certain testing paradigm and also differentiating between binaural and monaural timing. Also group delay threshold around 1ms.]
From 20:00 or so, it's interesting to hear him talk about the physiology I suppose. But by 21:45 as he concludes, he makes an enormous jump from basic physiological studies into the broad claim that "there is an incredible level of audio called High End Audio that goes far beyond the typical consumer audio level" which ostensibly achieves performance closer to the kinds of temporal resolution and reproduction of "reality" he's talking about! IMO, this is extremely problematic when there's no actual clear definition of what "High End" even means other than "expensive". How does he know that a Wilson Chronosonic XVX which must surely be "High End" due to the price is any more temporally resolving than a relatively inexpensive KEF LS50 Meta that retails for $1300; which I think for most of us would be more "entry level" than "High End"? I trust that most audiophiles would suspect that the little KEF is more time accurate than the Wilson given its Uni-Q design even if frequency response and dynamic handling likely would not be as complete as the Wilson.

I think he takes too big of a bite into the importance of time-domain effects at the expense of frequency response. Of course they're both important (this is why I recommend looking at modern DSP room correction for time and frequency domain optimization), but still, I suspect most listeners would pick a system capable of 20Hz-20kHz performance as sounding more realistic than whether the system is able to handle say 5-10μs of time & phase coherence when playing music. Since he keeps using Wilson Audio speaker pictures, I would love to see evidence of time and phase coherence on a step response on these speakers (without extra DSP correction) - by all means, have Peter McGrath set up the system optimally then show us if anything close to 5μs alignment has been achieved between all those drivers at the listening "sweet spot"!

Years ago, we talked about Kunchur's paper on the temporal resolution of human hearing and his false claim that 16/44.1 is inadequate; let's move on.

In the last year or so, for some reason, Kunchur has been wanting to prove something about audiophile cables.

Here's his 2021 paper: "Cable Pathways Between Audio Components Can Affect Perceived Sound Quality" (PDF) in JAES. As discussed already, this paper is odd given the lack of consistency between the cables used! There's nothing remarkable about potentially hearing a difference between the XLR and RCA outputs from a Berkeley Audio DAC into a $500 Straight-Wire Virtuoso 0.5m XLR cable vs. $50 Monster Interlink 400 2m RCA cable to the same amplifier, is there? Isn't that all he showed in the paper? What ever happened to simple high school science where we kept it at one "independent variable" in an experiment so we can actually understand the cause and effect of the change?

When the foundation of an experiment is constructed in such a poor fashion, it doesn't really matter how much statistical analysis went into the rest of the paper, does it? Yet over 10 pages of text, that's exactly what Kunchur does resulting in his conclusion that:

"This work shows that two system configurations differing only by the interconnect pathway are audibly discernable, even by average listeners with no special experience in music or audio."

We could just have easily concluded that the Berkeley Audio DAC's RCA output sounded different from the XLR. Or that the experimenter inadvertently draped the 2m length of RCA cable across a computer, picking up noise that listeners heard. Or that the Spectral amplifier sounds different when fed RCA vs. XLR. Perhaps most disturbingly, the article doesn't answer the simple question: "If that RCA cable was 1/4 the length at just 0.5m, would it have sounded the same as the 0.5m XLR cable in this set-up?"

In my day job, I actually have done peer-reviews for publications. I'm amazed that the JAES allowed a paper like this to pass the review process!

And more recently, Kunchur seems to have "doubled down" on even more questionable "research" with his latest paper "An electrical study of single-ended analog interconnect cables" (IOSR Journal of Electronics and Communication Engineering, 2021).

Kudos to Amir at Audio Science Review for his video breakdown of the article:


Seriously guys and gals, you don't need to have a PhD in physics or be an academic electrical engineer to recognize that the paper is unusual, showing measurable differences between RCA cables using bandwidths way beyond audio and non-audio signals as discussed in Amir's video.

Indeed, the whole notion that one can segregate RCA cables into tiers based on price is without any known factual merit; perpetuating the idea that "High End" = "High Price". In this paper, he uses US$5, $50, and $500 as representative of these tiers labeled as:
S ("super", "specialty", "Straight-Wire"?) = $500 = Straight-Wire Virtuoso RCA
M ("mid-fi", "Monster"?) = $50 = Monster Interlink 400
G ("generic", "General Store"?) = $5 = unknown cable
What kind of research is it that doesn't specify what cable "G" was when describing the method? And how then can any other scientist replicate this work? Again, don't we teach such basics to high school science students? Well, at least in this paper he standardized on 2m lengths!

Like his previous paper (comparing XLR and RCA of various lengths), the impression one gets is that Kunchur is just trying to razzle-dazzle readers with technicalities of questionable relevance - MHz frequencies, >20kHz FFTs with μV noise levels due to RF pickup, nanosecond pulse propagation speed over 4m interconnects (Why not kept at 2m?! Did he just use standard RCA-to-RCA coupler for 2x2m cables?) using the GHz digital oscilloscope, etc. Even if some audiophiles (like this) might find the paper meaningful, I trust that the mature, open-minded, educated, rational audiophile willing to use some critical-thinking will easily see the issues here.

Since Amir's video, Kunchur has issued his response - "Pseudoscience in audio" (September 2022). Wow! What irony! Are we now "tripling down" on the strong likelihood of persistent fallacies? Does he not realize that criticizing Amir as running a "cult" (in what way?) or having "zero journal publications" (emphasis his) are actually ad hominem attacks that make himself look weak in this academic debate? So what if Amir didn't published anything in the academic literature? Why does he have to? How does this diminish his criticisms about such an unusual paper?

As for the rest of his points, they are either technical allegations against Amir (1) and (5) or claims about whether the parameters are interpreted correctly or of significance (2)-(4). The latter points appear to be of the "How many angels can dance on the head of a pin?" variety as none of those address the key concern: his measurements simply do not appear to speak to audibility (much less the complex signals we're listening to called "music"!). 

The bottom line is that this paper just presents 3 cables with parameters that can be measured to be different. That's indeed nothing special. Obviously they're different products and if we measure down to a very detailed level, we will find variations. How ironic that Kunchur criticizes Amir for not knowing "the difference between correlation and causation"? Even if Kunchur shows correlation between "better" measurements with higher priced wires, how does he know this is the cause of the "sea of anecdotal claims by audiophiles that cables influence sonic performance" as stated in the opening paragraph?

Given that the paper's conclusions cannot even be fully replicated - for one, we still don't know what the "G" cable was - the only purpose of an article like this IMO is so that esoteric "High End" (= "expensive") cable manufacturers can reference it and try to sell you something you more than likely can't hear. Alternatively, one might speculate that Kunchur just desires the attention and wants to be "special". On that note, notice that these latest two papers have just one author - Kunchur himself. It's odd these days to have a paper showing original data without collaborators working on a thoughtfully designed experiment if not also helping with data collection. Also, I don't see any disclosures about the source of financing for the research or if he received any external support such as equipment like the cables used.

Finally, notice that the paper was published in the journal IOSR Journal of Electronics and Communication Engineering which is a publication originating from India, caters to research "especially those from the developing countries". These days there are thousands of journals out there - and a publication industry behind that. As we have seen through the COVID pandemic, not all research is of high quality, and likewise not all journals are of meaningful impact. Like other industries, let's not be naïve and recognize that there is a significant profit motive behind this, so churning through articles will increase the income for the companies doing this. Peer review is important when done right and Kunchur makes a big deal about that in his rebuttal of Amir, but let's be honest, it typically doesn't take a lot to get a "pass" from a couple of peer reviewers in lower quality journals.
[Those of us in the sciences know that there are clear issues including a "replication crisis" for quite some time now given the massive growth in the number of papers churned out these days!]

If we look at the graphic chart above differentiating science and forms of pseudoscience, do we believe Kunchur's work satisfied all the criteria of science? While he may be using objective data, are his conclusions actually consistent with the data, perhaps more importantly, with actual hypotheses being tested? Is there humility in his response to what Amir posted to consider that maybe he's not correct about the relevance of his findings about the cables and audio playback (or is he overconfident in his beliefs)? Does his paper show critical thinking or is he seeming to be working backwards from a desired conclusion (certain beliefs about "High End Audio" for example).

Interesting that he tells us he has a book on "High-end audio -- a scientific perspective" slated for 2025. Hmmm... Maybe he can better define for us what "High End" means by that time. Needless to say, the book sounds like a real page-turner if much of it is based on speculative research! ;-)

Anyhow, I'll leave you to decide, dear audiophiles. Be mindful of these contentious issues the next time you hear Milind N. Kunchur's name brought up or if some "High End" = "expensive" company wants to sell you wires referencing his journal articles.

Happy Thanksgiving to the American friends. Hope you're all enjoying the music as we enter the last month of 2022!

33 comments:

  1. The way ASR chooses the items it evaluates is everything but scientific.

    ReplyDelete
    Replies
    1. Hi Read,
      I thought the items were generally sent over by readers or manufacturers will also connect and provide devices to test.

      I don't follow the reviews regularly but will search to see if something has been tested, so not sure if there's a "flow" to how the tests are done.

      Delete
    2. Um, how and why is the choice of items Amir evaluates supposed to be 'scientific'? It's more or less random -- mostly gear that site users send to him. Please explain your accusation.

      Delete
  2. Journal reputation is mostly only useful to determine how likely it is there are some bad papers. Unless it's in Science or Nature, you'lld have to be familiar with the field to determine quality of papers.

    But, regardless of reputation, research can be judged based on what's in the article. Unfortunately there are major problems to be seen even if you don't know much about audio. Finding differences in measurements is not related at all to audibility, and it all comes down to the big elephant in the snake-oil industry: not accepting proper listening tests as valid.

    If you claim anything can make an audible difference, then a test will never be good enough. Most listening tests point to no difference with e.g. cables, but that body of evidence isn't enough to be convincing to some people.
    On the other hand, any single research that points to a difference, even meybe audible, is seen as validation of the wildest claims.

    The scientific evidence points towards no (significant) audible difference between properly made cables, DACs, or even high resolution audio. To prove this wrong, you need start with a convincing listening test where you can demonstrate audible differences between equipment that shouldn't be different.

    ReplyDelete
    Replies
    1. Yes, you make some great points there Steven, let's talk about a few items:

      1. Journal reputation is useful with the top-flight names. Even then we see instances where you wonder about methodology and whether the paper was written to de-emphasize obvious issues that could be obvious to those in the field. My concern is how Kunchur uses the idea that just because his paper has been "peer reviewed" (in his response to Amir), that somehow this makes the work more respectable. That's nonsense especially in the context of this journal that accepted such a paper, IMO.

      2. "Not accepting proper listening tests as valid." Yup, by this point, we have a mammoth in the room. When blind testing has been accepted in basically any other field of science to validate perceptual differences, for some to vehemently discount that in audio applications is plainly disingenuous.

      3. Having said (2), I think if the experiment is about subjective qualitative preferences, then a non-blinded test would be appropriate. For example, if we were to run tests of user preferences between one brand versus another, or maybe have focus groups determine design options, then fine. But these are more studies of psychological preferences, not tests of human auditory acuity nor sonic fidelity! I think the "pure subjectivists" sometimes conflate this and ask questions like "How do we measure emotional connections to music?" which are clearly more idiosyncratic questions to do with human psychology of consumer products than an engineering or basic neuroscience one! This was the basis of some discussions here:
      http://archimago.blogspot.com/2018/07/musings-zen-and-art-of-high-fidelity.html

      4. Yes, I think we've hit the "ceiling" for many devices now. Cables being most obvious since they're just pieces of wire and we've known about stuff like the LCR electrical properties, skin effect, shielding benefits, etc. for decades now within the hi-fi world. To make it sound like we're just embarking on some journey of discovery with such "mature" understanding would be fanciful and opens up non-reality-based thinking... Areas where the Snake Oil salesmen with their relaxed ethical values obviously would look for ways to exploit.

      5. Indeed, if Kunchur wants to make a claim that those fancy RCA measurements - like say, the nanosecond impulse propagation speed makes a difference, then let's "hear" it. Of course, even if he were to show in a well-conducted listening test that this made a difference, the critical-minded science-based audiophile could still ask if this made any difference with music listening as opposed to a test signal.

      Suppose Kuncher is able to show that some of these measurements on RCA cables made an audible difference. There's plenty of work for Kuncher to follow. Enough for an academic career even (maybe that's what he wants to do instead of Astronomy or whatever?). But first, he needs to be honest with himself and audiophiles. Since he publishes his work in the audiophile space and perhaps "to" audiophiles. At some level, "we" (audiophiles) are the more appropriate peer reviewers; not whoever anonymous folks at the IOSR Journal that likely has no interest in hi-fi and thought it was useful to have information out there in their journal about "High End" (whatever that is!) stuff. ;-)

      Delete
  3. I don't have time for the videos and all articles but I would like to share my views on the subject of importance of time domain behavior in speakers since I spent quite some time in recent years on experiments and "resarch" with my various diy active speakers on this subject.

    Once you get the "basics" right like smooth frequency response, constant or at least smoothly changing directivity and power response, low THD, 𝗜𝗠𝗗, inert cabinets (yes I know 99% of commercial products don't even reach that), improving time domain behavior is the only logical and important step towards higher accuracy of reproduction and increased realism.

    What we should achieve is optimally a minimum phase speaker via phase linearisation, from my findings FIR filters directly as a crossover is the best approach, other methods while sparing us from ringing impulse response introduce excessive group delay which IMO sounds especially bad in various ways. Interesting idea is also IIR crossover and then idealized FIR all-pass filter linearizing phase. With carefully chosen order of slopes I prefer the ringing and mandatory delay over excessive group delay (I use higher order in higher frequencies and lower near bass, still relatively high in comparison to passive designs).

    After such optimization results are dependent on the level of execution of the former "basics" but immediately the speaker is more convincing, dynamics seem more like found at a concert, everything sound "more right" but especially at lower midrange and upper bass - piano has more weight, soundstage gets more precise.

    That said none of this will be appreciated if there are obvious faults in magnitude, directivity and power response, also excessive IMD is especially destructive to realism, instruments simply don't sound as they do in real life then, it's like a comment tail of unwanted sound following every wanted sound. All of this will divert our attention from what would otherwise be gained by excellent time domain. Quiet room is also preferable. Never underestimate cabinet resonances and baffle reflections.

    Also Interesting compromise must be made between 2 way speakers and 3/4 way ones. 2 way speakers are way easier to optimize in time domain, the impulse, ETC, step, follow the ideal more closely, also less pre ringing and delay. On the other hand they suffer in comparison to 4 ways in dynamic ability, thermal compression and 4 ways are easier to optimize in directivity and power, that's why I ultimately prefer to make them.

    I hope I didn't do too many mistakes my English skills are not great.

    ReplyDelete
    Replies
    1. Great comment Tacet!
      Yup, I think many of us would agree with you. Appreciate the thoughtful discussion especially the importance of finding balance and the compromises that need to be made; for example not necessarily worry about stuff like ringing in order to minimize group delay. (I concur with that sentiment even with something less important like the DAC digital filters!)

      Hey, hope you get a chance to put out some of your findings and speaker designs online! Let us know if you do...


      Delete
    2. You can see my rambling (well really not ramblings, but educated experienced comments), on time alignment w.r.t. speakers on Audiophiles North America on Facebook. It is mainly a red herring, both because speaker preference is poorly correlated to it, and because there is apparently no mechanism in our hearing where it is even relevant. Minimizing group delay which requires phase alignment at crossover points does have both relevance to realized physiology, and to the numerous experiments that have been done on group delay, many with worse case stimulus.

      Delete
    3. Cool, thanks Cin,
      As I vaguely recall, was this the audiophile group that Michael Fremer joined awhile back and get called out on? And he subsequently complained about it in one of his columns?

      Delete
    4. I am not sure if this was the group, but I certainly would have called him out without hesitation. I don't think he is even particularly good at setting up a turntable :-)

      Delete
    5. Ahhh, it was in a Fremer article in Stereophile (May 2021):
      https://www.stereophile.com/content/analog-corner-307-hifiction-x-quisite-st-ac-power-ps-audio
      Looks like your Audiophiles North America Facebook group didn't give him a nice enough welcome befitting of his station and experience. Alas, you guys lost out on a Very Important Audiophile. :-|

      Delete
  4. It's not only shocking that JAES published his tripe, it's shocking that none of the comments on the paper on the JAES site clearly call him out as you have. I suspect there is some extremely misguided 'moderation' going on there.

    ReplyDelete
    Replies
    1. I don't know if specifically this paper, but I know Amir's comments were "moderated" from that page.

      Delete
    2. Wow. Assuming Amir left a comment that wasn't somehow rude or unbecoming, that's pretty crappy to have critical voices silenced from the JAES without some response or rationale.

      I assume this must be the bizarre RCA vs. XLR paper last year.

      Delete
    3. https://www.audiosciencereview.com/forum/index.php?threads/analysis-of-paper-on-measurements-of-rca-cables-by-kunchur-video.36800/post-1296296

      Delete
  5. First off, Kuncher, where audio is concerned, is at best a pseudo-scientist. His "vaunted" experiment comparing balanced and single ended connection, never once actually characterizes the whole signal chain end to end. He characterizes pieces, sort of, and poorly but there is no characterization of end to end. None, nada. How this got published is beyond me. It is garbage science.

    I will call out one error. We do have a dynamic range > 20-40db with music. We don't have 120db or even close, but we can exceed 40db. Space frequencies out far enough, and place them on the "best" spots on the Fletcher-Munson curve and you can get 60+. In real music, the purest bass tones mixed with some high, but not too high of frequencies. That 5usec is also binaural phase, not monaural timing. Obviously there are aspect of monaural processing that must be quick to enable 5usec binaural processing, but that does not mean we have the processing on the monaural side to detect monaural timing of that limited difference. In fact, most of the experiments that have been done, use both ears, and most have had major holes pointed out in their methodology (including Kuncher), who inadvertently created a spectral change as well.

    The one solid piece of evidence as it applies to music and timing is group delay. There have been numerous experiments on the audibility of group delay, i.e. the rapid change in phase over frequency. This is a potential real world result of "stuff", whatever we want to consider that stuff to be. All the experiments have been asymptotically reaching about 1msec, across a fairly wide frequency range. We get a bit below that with very specialized stimulus, that that is it. 1msec is rather large, larger than what you get in competently designed speakers and many orders of magnitude greater than what will happen with the electronics in a processing chain.

    Perhaps we need a letter writing campaign to the AES, IEEE and Kuncher's university. This is at the level of professional malfeasance.

    ReplyDelete
    Replies
    1. Thanks for the comments Cin,
      Appreciate the input on the dynamic range and temporal domain aspects and will add a comment in the text to review your message. That differentiation between binaural vs. monaural timing is certainly an important one.

      Yeah, don't know if a letter writing campaign would make much difference to the AES, IEEE, or University of South Carolina. I think the fact that Amir's video is out there, we're having this discussion here, and other similar discussions on forums like this:
      https://audiophilestyle.com/forums/topic/66805-pseudoscience-in-audio-milind-n-kunchur/
      I suspect will follow Kunchur in the days ahead as I'm sure those curious in his research will likely also be Googling his name and finding quite a bit of concern expressed online.

      Who knows, maybe he's a fine researcher in nanotech, and superconductivity. That's great, hopefully he can stay in those areas or at least come up with some better research.

      Delete
  6. I have medical degree like Archmago, and I'm costantly shocked by the poor scientific quality of even JAES etc. articles. I used to be a support member of AES and regular reader... And these MK "studies" are simply incredible crap. Harman studies as well have too low sample counts to be science, at best they could be describes as preliminary studies (like they often say in conlusion)

    Audibility of differences in eg. DACs and most amplifiers these days are neglible, so I am surpised of the publicity of ASR tests and ranking.

    But modern world has drifted too much to random bits of detailed info out of full context lifted to publicity, mostly by small web sites and individual posters. We must live with this, but fortunately and hopefully I will die soon...

    ReplyDelete
    Replies
    1. Not sure what you mean by 'the publicity', but the rankings of DACs and amps on ASR aren't accompanied by claims that one sounds better than another. They are simply referenced to measured performance.

      Delete
    2. With "publicity" I mean, how much debate they raise. Even if they are "simply measured performance" most people take his ranking of SINAD as measure of overall quality, preference for purchase. IMO much more important are basic features like inputs/outputs, volume adjust, crossfeed, channel matching etc. hearable issues, or user experience or "beauty" of casing.
      https://www.audiosciencereview.com/forum/index.php?threads/schiit-magni-heretic-headphone-amp-review.39518/

      Delete
    3. Hey Juhazi and Steven,
      Yeah, I think some folks read too much into a few dB of SINAD ;-), or get too wrapped up in the ranking graphs. As humans, simplicity catches our attention like the brief "sound bites" in the news.

      As far as I'm concerned, a mere 1kHz THD+N of -100dB or better is good enough for me when it comes to a fine measurement and could mean the device sounds "good enough".

      SINAD doesn't imply that the DAC/headphone amp has flat frequency response. It doesn't imply any filter characteristics, or jitter anomalies (although both would typically be very subtle). It doesn't tell us if distortion might be elevated in other frequencies or at various output levels. Ultimately it also doesn't speak to device matching or of course how anything sounds in the acoustics of one's room. Not to mention if the user interface is decent or if it looks any good.

      As a simple single measurement though, it does at least speak to some level of noise-free, distortion-free output at a frequency our ears are sensitive to from the DAC chip and analogue output stage.

      So long as we all can see it for what it is, and as usual, not get too dramatic about things - the "subjectivist" drama of the expensive-cable snake oil salesman, or the "objectivist" drama of a dude who insists a DAC that measures 110dB SINAD is clearly better than 105dB - I think we can all get along. ;-)

      Speaking of appearance, I was curious what people thought of the HiFi Rose RA180, here's a poll for folks to weigh in:
      https://forums.stevehoffman.tv/threads/poll-do-you-like-the-look-of-the-hifi-rose-ra180-front-panel.1161772/

      Delete
  7. Dear Archimago, I re-read your Summer Musings dated 22 August 2020, linked in this post, in which you discuss the positioning of the loudspeakers in a room (with 10° toe-in for your speakers in your listening room).
    In order to widen the optimal listening area of my stereo system (with two loudspeakers) and share it with the occupants of a three-seat sofa, a friend suggested me to point each loudspeaker at the opposite end of the sofa; so the radiation pattern of each speaker tends to compensate for the attenuation due to loudspeaker-listener distance. The result seems satisfactory to me. What do you think about it?
    Thank you very much.

    ReplyDelete
    Replies
    1. Hey there MTB,
      Yeah, that's an interesting idea and one I have tried in the past as well. Depending on the directivity characteristic of your speakers this might or might not work well. Try it and see if you notice an overall improvement in stereo imaging in all 3 seats.

      For me, while I also will have friends and family sitting on the sofa for movies, my priority is still the center "sweet spot" where I do listening for reviews or just relaxing at night.

      As such, I would recommend empirically toeing in using the mono pink noise signal and see if you can find the angle that "anchor" and "focus" that phantom image. You can then again compare pointing at the sofa ends vs. that empirical angle to find your preference.

      Have fun! Much depends on your speakers, room layout, and preference!

      Delete
    2. In my experience this sort of increasing crossfeed might work in nearfield, but not at typical living room listening distance. That's because at longer distance reclected sound "mixture" becomes more important than direct sound and stereo imaging is poor anyway. Speaker directivity characteristics may or may not be well suited for this, spl response might change too much.
      But it is easy to try and costs only the task of lifting your butt from the chair for a while. Good excercise!

      Delete
  8. In this hobby, if we can call an endless journey into the difficult understanding of a very broad subject like HiFi that, there are an abundance of wise-ass self-proclaimed 'guru's' who happily let their mindless puke out all over the internet, Dr. Milind N. Kunchur being one sad example. Personally, I wouldn't read his coming 'book' if he threw in in my lap. Too many of that breed has no more understanding of HiFi than an average audiophile with a good number of years of experience to prove it. Let's be clear on one thing: NOBODY knows everything!

    It saddens me to see such morons publish so-called 'work' that obviously repels knowledgeable audiophiles, but which may lour rookies into believing his nonsense. How is such a fool able to even occupy a position at a University?
    Sorry for my bitter rantings, but I get sick from reading his nitwit babble.

    ReplyDelete
    Replies
    1. Hey Duck,
      Sounds like you're holding back on what you really think about Dr. Kunchur ;-).

      In the fable of the "The Emperor's New Clothes", it was the child who had the courage to speak truth to something that was obvious. So too in areas such as audiophilia these days, I believe that many and I hope most audiophiles have enough common sense like the kid witnessing the pompous parade to call out emperors, high priests, and academics like this for their nakedness.

      Delete
  9. To preface, this is not an audiophile comment, but rather a reflection on the validity of published "scientific" articles. Arch, as a physician and occasional peer reviewer for medical journals (which have a much greater importance than JAES, in both financial and general humanity aspects) you should not be surprised that this was published. Even the "top tier" of medical journals, e.g., NEJM, Lancet, JAMA, etc., publish tripe that should often be shot down based on the methods section alone.

    ReplyDelete
    Replies
    1. Hey Rob,
      Absolutely. Just look at how many articles are recycling of older data, sometimes shoe-horned into meta-analyses using questionable methodology, summaries based on "systematic reviews", or "significant" results based on statistical analyses with practically no real-world clinical or quality-of-life relevance.

      There are good scientists, but a multitude of articles are really in the "Industry of Science" making a living out of a funded system, scurrying along their academic career path. Such is the way of the world, including medicine.

      Delete
  10. If a cable improve the sound of music playback and my listening pleasure and I find it worth to pay for it, I don't need anyone to prove anything to me. I don't go around telling people not to spend so much on fine wine if I cannot detect the difference in the taste

    ReplyDelete
    Replies
    1. Your fundamental mistake is that the difference in wine tastes is real (having a very sound chemical basis) , but the difference between cable sounds isn't. It's entirely imaginary.

      Delete
  11. Thanks for shedding light on the intriguing research by Dr. Milind N. Kunchur. It's fascinating to explore the intersection of audiophile science and academic research, especially when it challenges conventional wisdom in the field. Your critical analysis prompts us to think deeper about the claims made regarding high-end audio and the discernibility of factors like cable pathways.
    https://goodsresponse.com/21appropriate-ways-to-respond-to-i-am-tired-text/

    ReplyDelete