in ,

KIH #25 – What do measurements really tell us?

  • Measurements. They can be used in one-upmanship fashion. Magazines and reviews which do them are serious, scientific and objective. Those which don’t, aren’t. Doug Schneider of the SoundStage Network for example says, “I don’t take magazines too seriously that don’t do them.” Can measurements predict performance? Doug who prides himself on taking the best loudspeaker measurements in the industry: “You must have sufficient measurements to predict… in my opinion, no magazine produces nearly enough measurements to predict anything with great accuracy, including us.” If that’s the case, what are measurements good for? Bragging rights? Doug believes that at the very least, measurements reveal whether a product has been competently designed.

    Another US publication which conducts and publishes measurements is Stereophile. It’s not at all uncommon to find disparity between their measurements and the opinion of the writer who actually heard the product [Ed – Stereophile’s Croft Acoustics Integrated amplifier review is one recent example]. If bad measurements quite routinely don’t correlate or mean what they seem to, does it imply that good measurements prove or substantiate a good review opinion? Couldn’t one just as easily claim that if (within reason) bad measurements aren’t all that meaningful, neither are good ones (if they measure things which aren’t as important as we think)?

    For example, the typical nearfield speaker measurement is done at 1m/1w. That’s to simulate anechoic conditions and to not capture room effects which, obviously, would differ from room to room. The irony is that without room effects, measurements won’t tell us what this speaker will sound like in our room. In fact, the most useless and abstract thing about expensive anechoic speaker measurements from the consumer perspective is that they show premature roll-off in the bass. This isn’t at all representative of what that speaker will actually do in a reflective real-world environment. The anechoic measurement will show a steep roll-off at 100Hz. In room, that speaker might do solid bass to 40Hz. That’s a huge difference. Without proper interpolation from knowing how to read an anechoic result, the measurement itself remains grossly deceptive.

    Does your room like this? If not, should you care what a speaker measures like in a room like this?

    Amplifier measurements might show total harmonic distortion and intermodulation distortion figures. Here it’s easy to believe that lower must be better. Just so it overlooks how the ear/brain responds to and filters harmonic distortion; how certain kinds of distortion are more benign than others; how amplifier and speaker distortion interacts, sums or partially cancels. Our typical hifi measurements don’t show how harmonic distortion shifts with amplitude, i.e. how distribution changes with SPL. They often don’t show sufficient increments to track how an amp behaves at 1w vs. 10w vs 100w. It might be a peach if used up to 5 watts but turn into a distortion generator at 20. Distortion measurements at 1kHz tell us little to nothing about the amp’s broadband behaviour.

    How about the effects of voice-coil heating on speaker distortion? Even if one did show high-power measurements, would they include changes over time to illustrate what happens when a given loudspeaker is played loudly over 15 minutes? How does one accurately represent an omnipolar speaker’s in-room behaviour with nearfield measurements like a Duevel, mbl or German Physiks? How about side-firing mid/woofers crossed at 1kHz? To begin with, are static test-tone measurements even remotely representative of complex music signal? These are just some of the many valid questions one may ask on the subject. For our purposes, the most important one is whether the typical review measurements are all that useful to a potential buyer.

    What meaningful things can they tell us? They can, for example, confirm or dispute an amplifier’s power specification. Does it really make 400 watts into 4Ω below 1% THD as claimed? What happens when that amp gets thermally stressed to the max? Will it blow up? Will it trigger protection or blow a fuse? Will a tube amp’s output transformer make 30Hz and 20kHz without roll-off? In speakers, non-linear frequency response like suck-outs and peaks particularly around the crossover points can show nearfield issues which may or may not be fully or partially obscured in the actual listening seat. And so on. There are many things which measurements can confirm or refute.

    On the manufacturing end, it’s clear that measurements are mandatory. There is parts matching to insure they’re all within 0.25% or 5% tolerance (whatever that maker’s standard may be); or response matching between a left and right speaker plus matching it to the reference lab model. Quality control without measurements is unthinkable. So is digital design which can’t even be listened to until the signal is in the analogue domain. Sources of noise within a circuit must be tracked down with measurements. Attempts at circuit distortion reduction and PCB layout is tracked with measurements. Speaker enclosure behaviour is quantified by measurements. So is the efficacy of properly engineered isolation products. And so on and so forth ad infinitum.

    In fact, it’s only with very advanced simulation software like Comsol that complex behaviour across a variety of interlinked disciplines like mechanical, electrical and acoustical can be modelled to cut down development time, money and endless prototyping. The most engineering-driven most experienced companies may nail 90% of a product’s design entirely in the virtual domain. Companies like Goldmund write their own simulation software. YG Acoustics have written proprietary software to design their crossovers. Etc.

    At what point listening tests kick in differs from maker to maker. At some point, they invariably do. Now listener feedback begins to interact with measurement verification to finalize the remaining 5% or 15%. This can include parts selection where different capacitors or transformers may measure identical but sound very different. Back on the consumer side, Doug is right to say that whilst measurements may predict a lot less about final performance than we’d like them to and do so with far less accuracy than ideal, they can at minimum reveal whether a product was competently or shoddily designed; and additionally provide useful information to those who know how to read them. This sadly excludes the majority of consumers. Making measurements meaningful relies not only on knowing how to interpret them, it requires that one tie together a whole suite of them in an interdisciplinary multidimensional fashion to arrive at a useful bigger picture that accounts for how they interact.

    That there remains a big gap between subjective listening impressions and a fuller correlation via more complete measurements is plain. To begin with, it requires a far more complete understanding of how the human brain processes sound than we have at present. The hifi industry is far too small to finance the necessary cognitive brain research. Industry at large has little to no interest to further that understanding unless it could be monetized far more significantly. On the product side, we often don’t yet know what (else) to measure. The most current example are USB and Ethernet cables and peripherals for audio use. Many users hear differences. Hardcore IT experts are adamant that if basic specs are in place, nothing else should or could make any difference.

    Not that long ago jitters were what happened to students before a test; or to folks about to get married. Today jitter is an acknowledged phenomenon. Yet devices like the Uptone Regen, Audioquest Jitterbug and Schiit Wyrd still represent engineered solutions which address issues whose very existence is just beginning to be acknowledged by the very few. But forward 5 years and “Ethernet flue” will be in everyone’s vocabulary as something even the most affordable DAC addresses in some form.

    Does your listening room look anything like this? If so, wouldn’t you want to know what a speaker sounds like here? If so, can you really know without listening first? Might you need help determining where to best set it up?

    For now, reading consumers believing in the usefulness of measurements already have certain sources. With it they enjoy monthly opportunities to correlate reviewer commentary with measurements to learn which ones are most likely to predict anything of usefulness; and which ones merely look good, scientific and serious to add perceived gravitas to said review and its publication. Meanwhile we have popular electronics from manufacturers who have stated to never yet have measured anything which correlated with what they hear; we have makers who claim to finalize their products purely on the strength of a suite of ‘perfect’ measurements; we have amps which measure as perfect as current technology allows yet have listeners claim they sound bad; and continue to have amps which measure poorly but enjoy plenty of sales and contented listeners.

    If we add up all the evidence and what’s between the lines, what does it really say?

    Srajan Ebaen

    Written by Srajan Ebaen

    Srajan is the owner and publisher of 6moons. He used to play clarinet at the conservatory. Later he worked in audio retail, then marketing for three different hifi manufacturers. Writing about hifi and music came next, then launching his own mag. Today he lives with his wife Ivette and Nori and Chai the Bengal cats in a very small village on Ireland’s west coast, between the holy mountain Croagh Patrick and the Atlantic ocean of Clew Bay in County Mayo’s Westport area. Srajan derives his income from the ad revenues of 6moons but contributes to Darko.Audio pro bono.


    1. Hi Srajan,
      I’m ambivalent when it comes to most measurements.
      Speaker sensitivity is handy as the more efficient styles open up a whole raft of low powered amps – modern or vintage, solid state or valve.
      The flip side is that the more sensitive speakers can/will reveal the short-comings of other links in your supply chain.
      Vintage equipment measurements may not stack up when compared to more modern equipment but can perform with amazingly glorious results. In my experience this holds true for both amps and speakers.
      Compatibility with existing equipment is another often overlooked consideration that is capable of making the most scientific test results look like gobble-de-gook.
      Factoring in the listening rooms personality with everything else, it seems clear to me that the ultimate test instruments are your ears and that the laboratory test measurements are, in the eyes of this consumer, merely a guide to help filter the decision making and auditioning of a future purchase.
      As ever Srajan, another enjoyable and thought provoking article.
      regards, Ian

    2. I feel that the traditional methods of measuring parameters and performance of audio equipment are ridiculously out-of-touch with real life. They should be discarded and the new methods and procedures should be invented.

      At the same time, my opinion is, that a solid set of procedures reflecting more realistic circumstances of typical rooms (many types of rooms, not just one) would be the most reliable source of information about the equipment, because human hearing comparisons method is almost worthless – everybody’s ears and brain process sound differently on the physical level, everybody’s psychology of finding the sound pleasant/unpleasant is different and everybody’s approach to the methodology of comparing audio properties is different…

    3. A very interesting and thought provoking article. If you consider other larger industries where acoustics are important, much effort is spent in benchmarking and testing products, and in developing advanced simulation models to perform virtual engineering and design. A knowledge database is developed so that the relevant physics, component and in-situ performance can be correlated.

      In comparison, resources are not really available in the hifi world to do this, even though the problems are no less interesting.

      What we do have in the hifi world are some magazines making a few measurements at the component level, and importantly, some reviewers like yourself who describe the listening conditions (the room setup) in their reviews to help provide the in-situ performance context.

      As you state, what does this all really say for the average consumer? Who has the time to sort through all of this unorganised information to make an informed purchasing decision?

    4. If we, as consumers, are most curious to know what something sounds like, having a measurement confirm that an amp really outputs 400 watts into 4 ohms; or that a speaker is really 85dB, not the 88dB claimed… these measurements tell us nothing of the sort.

      If we want to know whether and how a speaker will soundstage, image, focus and project, we don’t really have measurements that give us that information. If we want to know whether an amplifier will sound ‘fast and lucid’ or ‘warm and comfortable’, crisp on the leading edge or lazy on the decays… do we have measurements (or a combination of them), which convey those personalities in any predictive fashion? What measurements correlate with tone density or a caffeinated spunky personality

      If we know the output impedance of a preamp and the input impedance of an amplifier; the impedance swings and phase angles of a speaker – can we assemble all of that information into a clear picture in our mind of how these components will *sound* together?

      If we look at the jitter graphs of a DAC and how high or low its noise floor sits, can that be converted into a sound expectation? There are tube preamps with barely 80dB S/N and solid-state preamps of 120dB S/N. On paper, that’s a huge difference. But in the listening seat at home, what should we expect from these isolated measurements and now they might interact with the rest?

      It’d be interesting to hear from readers which measurements they find the most useful and *telling* as far as sound goes; and which ones they can’t do anything with at all…

      • Ditto agree wholeheartedly. Who would purchase a valve amp in comparison to a class D amp on Performance figures alone? Not me for sure.

    5. I wonder whether anyone is measuring violins, for example. Why people find it difficult to think of hifi equipment as “instruments for playing music”? If they did, measurement would remain where it belongs – on the manufacturing side (and even there brilliant manufacturers such as Heed Audio remain sceptical, not to say militant about measuring, or the importance assigned to it). The problem is, as with quality violins, you cannot play anything you would like to. And with real-world – as opposed to online – dealers finding themselves in dire straits, hifi reviews become the main – for some, the primary – way of addressing this problem.

    6. We need to strap loudspeakers to our backs and do a lap-time round the Nordschleife or Isle of Man, on foot. That should be the only definitive measurement method.

    7. Who in the hifi world really knows what few key measurements are relevant for an entire system? I would be very interested to hear a respected designer like Nelson Pass state that “for amps, X & Y are important, and forget about all the rest”. Would he be willing to do that even?

      Personally, I’m trying to ignore almost all measurements and almost all specs that are listed in magazine reviews and product literature. I’m basing my decisions primarily on my perceived trust in the capabilities of the designer and the brand name, and in trusting the opinions of some reviewers who I feel have demonstrated competence and consistency.

      Since it is now very difficult to audition many components in a physical store or in your own home, what else can you do as a consumer. This is especially true if you are interested in non-mainstream products.

      • Fantastic.

        Wiggle room is often only an issue for those seeing the glass as half empty. These guys often go by the names of Coulda, Woulda and Shoulda.

        Nearly everything in life comes with wiggle room, no? One only has to look at the debate surrounding Pluto – is it a planet or not? Or global warming. Or vaccinations. Interpretations of the same measured data set can vary immensely. Of course, this is where objective truths REALLY matter. The latter two examples are a matter of life and death.

        Hi-fi is not life and death and yet you wouldn’t know that from the debates that rage elsewhere on the ‘net.

        I only point this out after a weekend of browsing various discussions pertaining to measurements in audio. As you say in your piece Srajan, some measurements are properly useful: safety checks and being ‘as described’ are two fundamentals that carry over to almost every other consumer goods sector. Beyond that it gets fuzzier – more subjective perhaps. Does the measurement being taken inform real-world use?

        As often seen with publications that DO conduct measurements, when something presents as unusual/’erroneous’ in the measured data, evidence of the same doesn’t always show up in the subjective listening report.

        Flipping it around, if we are to apply proper scientific rigour to these inconsistencies then we should conclude that measurements cannot be relied upon to substantiate subjective listening. And yet calls for *proof-through-measurements* keep on comin’.

        Besides, even when presented with measurements (or ABX results), hardcore detractors simply move their distrust to poo-poo-ing the measurement methodology or the nature of the measurement taken. And so their glass returns to being part empty.

        I have to wonder if a certain portion of armchair audiophiles (Coulda, Woulda and Shoulda and their pals) who *insist* on measurements will ever find what they are looking for? Realising that the glass will never, ever be full is one step closer to proper enlightenment, whether it be hifi or any other life pursuit.

      • Thanks for that, Srajan. Mr. Pass does indeed provide a few key clues there regarding amplifier harmonics and distortion.

    8. This article and its assumption that measurements do not reflect the ‘truth’ of what people are hearing ignores one very important aspect: that all devices engineered for music playback are machines. Those are usually engineered to follow the specs the engineer determined beforehand. And because they are machines they are unable to interpet the music they´re playing, they don´t know what they are playing (contrary to what audiophiles usually believe). To us it might be music, to them it´s just data, transported through parts working with electricity. All of them are working within predetermined parameters, whether it´s some DAP, Network player, even vinyl.

      Therefore: if it sounds different, it can be measured. But for that to happen, someone must measure it. Meaningful measurements are complex and a lot of work, for that reason people seldomly perform them. Besides, not many people understand them. Not even me. I perform measurements myself for my blog – but I don´t have delusions of grandeur and would call them meaningful. Yet I still include them so that I at least have a look at the basics.

      And comparing measurements to the discussion about Pluto or vaccinations is stupid. If Pluto is a planet or not has to do with finding a proper term for that makes use of its (comparably) tiny size. Vaccinations? The science is clear on that: if you don´t do it, you increase the risk of death. But the discussion is fueled by vaccination-oppononents who just don´t understand the data they´re looking at. Ergo: wrong interpretations.

      The same for audio: IME, audiophiles rarely understand measurements when looking at them. Some don´t want to understand them. Some want them to be interpreted so that it reflects their own world view, their belief. After all, audio has a lot to do with faith, measurements are a danger to that faith (because it presents facts) and so they must be banned from one’s view of the world (“I don´t listen to test signals”).

      • “And comparing measurements to the discussion about Pluto or vaccinations is stupid. If Pluto is a planet or not has to do with finding a proper term for that makes use of its (comparably) tiny size. Vaccinations? The science is clear on that: if you don´t do it, you increase the risk of death. But the discussion is fueled by vaccination-oppononents who just don´t understand the data they´re looking at. Ergo: wrong interpretations.”

        That was me who commented as such, not Srajan (who wrote the piece).

        But that’s my point, interpretations still present as a factor DESPITE evidence pointing to a very specific objective conclusion for those that fully understand the measurements. Do you think the majority of readers of the hifi press understand the measurement data put in front of them? Like you, I don’t (and I count myself in their number). Hence the room to wiggle through possible, or even wilful, misinterpretation for those so inclined. Talking of which…

        “Some want them to be interpreted so that it reflects their own world view, their belief.” <--- if this doesn't describe anti-vaxxers, I don't know what does."Therefore: if it sounds different, it can be measured." <-- This is where my own thinking gets fuzzy. What about the possibility that two pieces could measure identically but sound slightly different? In which case, are we measuring the right things? And therefore, do we know what to measure instead? And how do we know for sure that'll be the right measurement to take? Is it possible that some audible differences remain out of reach of modern-day measuring equipment?Pursuing this line of questioning is fine for getting down to the nitty gritty of differences but does it help the end user any? Without proper meaningful interpretation, plus a healthy dose of real world relevance, we end up dancing around the physics. I'm not saying that's not important. Cleary it is to some people but to imply (not that you have) that it is therefore important to EVERYONE buying audio gear is a little arrogant, don't you think? As you point out, it's only really relevant to those who fully understand measured data, a VERY small percentage of audiophiles and electrical engineers.

        • Sorry, that I mixed up the two of you.

          I´m quite sure that the majority of readers don´t understand measurements when they´re looking at them. Does that automatically mean that they´re meaningless and shouldn´t be done for that reason?

          Measurements and studies on real-world situations are a bit different. Studies about vaccinations are about a chaotic system (a group of humans and their reaction to / interaction with medicine) while measurements for audio gear concentrate on a closed system that isn´t chaotic. It´s the opposite, it´s predefined, it´s behaving according to specified parameters. Therefore measurements don´t need to be interpreted. There´s a reason that some (not all) measurements are standardized, you can only do that if the result is repeatable. And with audio which is an unchanging system, you can repeat measurement and most likely will end up with the same results every time. Try that with any medication.

          Two pieces can measure identically yet can sound slightly different. The important point here of course if you have measured all that was to measure. The measurement I most often miss everywhere are phase distortions / phase delay. Many high end devices fake spatiality by introducing severe phase distortion on playback. But no one measures them, hence, those wonderful stage response is produced by something ‘magical’ and people say “We cannot measure differences.”

          And I don´t think it´s arrogant to wish for more educated people, especially if they have enough money to spare and are able to care about expensive audio gear. You see, measurements tell you something about any device you want to buy. But many high end manufacturers are safe and can fake anything they want (and they do!) because they know that no one of their potential customers will look at or understand measurements. In the end, so many people are getting fooled just because they are lazy.

      • Marlene, my sentiment, exactly!
        Even if measurements are not understood by masses, even if they not always reflect one’s preconception of how a particular piece of equipment should sound (based on one’s previous experience with the same brand or even with the exact same model but in different room and with different peripherals), measurements and standards are the only solid base to draw conclusions from.
        I respect some reviewers’ experience and knowledge (looking at you, Srajan and John), but there is no way for you to convey to me in writing any audible characteristics of something as complex, elusive and indescribable as sound and music. As they say, “writing about music is like dancing about architecture”.
        So, do not fear that numbers will put you out of business. Just learn interpreting those numbers, convey that interpretation to us and promote refining algorithms used to measure and correct the sound delivery. After all, you are both open-minded guys, so it’s not like you got to break out of some kind of dogma…

        • “even if they not always reflect one’s preconception of how a particular piece of equipment should sound”.

          “measurements and standards are the only solid base to draw conclusions from.”

          Aren’t these two statements a little at odds with each other? Reading them sequentially, I get this: “even if they don’t always reflect how a particular piece of equipment should sound, measurements are the only solid base to draw conclusions”. But if said measurements don’t tell you something about how a piece of gear will sound, what *do* they tell you that’s worth knowing?

          That is, what kind of conclusions do you draw from which measurements?

          Would you be kind enough to exemplify?

          • Sure, John. You misunderstood me. At the surface, those two statements might sound conflicting (not for me, though). To understand them, you would have to return to my initial post in this discussion, but that would mean missing my point again. Instead, read this one, please.

            “What kind of conclusions do you draw from which measurements?”

            My answer: at this point it is almost impossible to draw conclusions from measurements – basically, because there is so few audio magazines that are willing to acknowledge the importance of standardized methodology of making measurements and even fewer that provide them. They don’t hire qualified acoustic specialists, because they are of the opinion that “reviewers” (often – music connoisseurs) are able to do the job sufficiently.

            Well, no, John. Reviewers are not able to tell me what the sound is like when they listen to it. There is simply no way to do that. If sound was art, then the most eloquent reviewers would have a shot. But sound and acoustics are not art. They belong to the domain of science and as such, they comply with the laws of physics.

            I am no scientist or industrial researcher, but I can see at least some things we should ask for, to get a better picture of what to expect from a piece of audio equipment sitting on a shelf in a store.

            Firstly, we need a standardized setup for making measurements. No more proprietary equipment and methods used by individual manufacturers, who, right now, do whatever suits them. Perhaps something like what is used at the National Research Council in Ottawa would work – but I’m not talking about the room itself. I’m talking about the standardized equipment and methods of research.

            As I said in my first post, I think we need more realistic measurements which would include room conditions (several algorithms, covering different kinds of rooms).

            All that gibberish stating that sometimes the equipment does not sound nearly as should be expected from measurements is caused not because measurements are worthless. It is caused by the fact that the reviewer takes them out of context by using innumerable variations in his/her listening setup and by ignoring the fact that every piece of their equipment and room conditions is affecting every other piece.

            If you eliminate this variability, the numbers will start making more sense. But that demands a lot of big changes to be made – both in the industry and in the audiophile community. Many manufacturers fear those changes, because they would reveal enormous amounts of snake oil and bull*hit. Many reviewers fear those changes, as well, because they think that would be the end of their careers (they don’t have to – just adopt the numbers and measurements).

            • Sure, OK, all noted. You talk about a standardized system – gotcha.

              Can you specify some examples of: a) measurements you would *like* to see become part of that standardized system and (crucial to this discussion) b) what those measurements would tell us about how an amp, speakers or DAC might sound?

            • John, all measurements are important, not a single one or even few of them. Otherwise, we get not enough info to form an opinion (it’s still just an opinion, but an educated one). Those that I miss most are room correction algorithms that could be input in our receivers, pre-amps, amps, whatever – to make adjustments for our specific situations.

              We do have specialized devices and software for correcting those room anomalies, but this is an approach from the wrong end. The room correction process should be implemented at the beginning of a chain, not at the end of it.

              This whole discussion is skewed toward the devices, measurements, procedures and software that exist right now. My point is, all this ought to change in order to devise better methods – both in measurements and in the way they are used (if they are used at all).

            • Hey again Rob. Please forgive me for being thick here but you say “all measurements are important” but then talk about room measurements. Are those not unique to the room itself?

              Without wanting to negate the importance of how a speaker interface with a room, it’s performance remains room dependent. Less so with DACs and amplifiers.

              So let’s put the room issue aside for one moment. Let’s also put speakers aside for a moment too. And let’s assume I had access to ANY measuring device available in the world today, irrespective of cost.

              1) What specific measurement(s) could I take of a *DAC* or *amplifier* and 2) what would that same specific measurement tell us about the sound of the product being measured?

            • John, I’ve stated at the very beginning that the existing measurement methodology is very unrealistic and hardly helpful, therefore a new set of measurements should be devised.

              I’m not sure if this exchange between us makes any sense, because I am insisting on changing the way things are now and you are insisting on using (or, rather, not using) measurements as they are in the present status quo. That’s the source of constant misunderstandings, for example, the reason for my yearning for room-correction algorithms/presets included with the equipment we buy. This is impractical (if practiced at all) in current manufacturing processes.

              We could go on and on in this manner and not arrive at any conclusion at all. So, forgive me, but I am exiting this discussion…

            • I’m sorry you feel that way, Rob. I was simply seeking greater clarity from you.

              I think I was confused by this: “existing measurement methodology is very unrealistic and hardly helpful, therefore a new set of measurements should be devised.” that followed this: ““measurements and standards are the only solid base to draw conclusions from.”

              My mistake.

              So you’re saying measurements are useful but not as they are currently executed? But what of those measurements offered up by some hifi publications? Are you saying they are of little-to-no value to readers?

              What I’m not understanding though is which measurements *would* be of use to readers and consumers?

              I think what you’re possibly shooting for is a more holistic approach – having anomalies (room, speaker etc.) corrected after the fact? Manufacturers such as Linn, Devialet and DEQX (to name a few) already meet some of those needs, no?

    9. The easiest example, mentioned in my piece, that we often don’t know what to measure for occurs with parts swaps. It’s routine that manufacturers (or after-market modifiers) will roll capacitors, even transformers. They will (have to!) measure the same in all important parameters yet often sound distinctly different to rely on listening and what said designer thinks sounds ‘better’ or ‘more correct’.

      Which is where the wiggle room begins. ‘Better’ and ‘more correct’ are wide open to interpretation. It begins on the design side and continues on the consumer end. But rather than devolve into abstract discussions, my underlying question was, what/how do measurements predict what something sounds like?

      Are there measurements for soundstaging, imaging focus, depth of field, dynamic contrast, tone colour saturation, density, zippiness… i.e. all of the qualities reviewers talk of and customers are interested in? If so, which measurements correlate with which quality?

      • “But rather than devolve into abstract discussions”. Apologies for that. Early morning coffee went to my head.

        Not entirely answering your question but talking to your first point, Srajan, this chap suggests that the microphony of capacitors – as determined by their size, shape and material composition – can influence audible differences. Admittedly though not the measurement-audibility correlation that your last question seeks.

      • I recall talking to Melbourne-based amplifier designer Hugh Dean a couple of years ago. He opined that even order harmonic distortion sounded more pleasurable / easier on the ear (‘warmer’) than odd order which he described as lending the sound a certain ‘crispness’ (which he didn’t like but conceded that other listeners might).

      • Start with what can be measured in your listening room, and then work backwards from there. Sound pressure amplitude and phase, air particle velocity and surface vibration are the purist forms of what you can measure. From these, the usual quantities like sound pressure levels and reverberation times can be estimated, and the complete sound field in the room can be known.

        Sound radiation from loudspeaker driver and cabinet designs, and loudspeaker positions (reflections) can be observed.

        Beyond this physical behaviour, then you get into the electronics of the system. Someone will also have to tell you about the psychoacoustics, i.e. what traits of the physical room acoustics quantities are desirable.

        Keeping this all in mind, I think it is a real challenge for anyone making electronic hifi measurements to really know if their measurements are relevant.

      • I´m sorry, but with this comment you gave an excellent example for why measurements are important. Question: what is the meaning of expressions like ‘soundstaging’, ‘imaging focus’, ‘depth of field’? Does it mean what I want it to mean, holographic stageing, precise placement of instruments? Or does it mean, that the soundstage of some device is as wide as possible? What is the meaning of ‘tone colour saturation’ (?), ‘dynamic contrast’ (never heard that one before), ‘density’, etc.?

        Those are all extremely imprecise descriptions of sound. More helpful are cold and sterile… yes, numbers. Because, again, we are talking about electronic devices, applied physics, if you like, therefore, numbers are extremely representative. Much more than meaningless expressions every person can interpretate differently.

        Reading all this, I really have to think about a way to describe my listening experiences when I´m writing my reviews. I have been way to imprecise.

    10. The 2nd vs 3rd dominant sonic signature is well known. It’s the presence of higher-order artifacts (particularly the 7th in even minute doses) which becomes troublesome. But even there we have THD interactions between amp and speaker where isolated measurements (just the amp, just the preamp, just the speaker etc.) don’t reliably predict the final outcome.

      As Nelson Pass has stated many times, 2nd-order triode vs. 3rd pentode THD has a nearly even split of admirers. He’s always had amps of either flavour and sales show that buyer preference is about 50:50. That alone tells us that ‘right’ or ‘better’ are in the ear/brain of the beholder. And this is very basic stuff still.

      I’m more curious whether any of the measurements which accompany reviews in certain mags have usefulness for the reader. If so, which are deemed most useful; and what, exactly, do they tell us about what type sound to expect?

    11. This is possibly the dumbest/silliest article on audio I’ve seen this year. Kudos.

    12. Maybe you want to tell this guy he’s *got it all wrong*?

      The Measurement and Calibration of Sound Reproducing Systems

      For decades, it has been widely accepted that a steady-state amplitude response measured with an omnidirectional microphone at the listening location in a room is an important indicator of how an audio system will sound. This paper examines both small and large venues, home theaters to cinemas, seeking a calibration methodology that could be applied throughout the audio industry. Room equalization schemes adjust the room curve to match a target believing that this ensures good and consistent sound. The implication is that by making in-situ measurements and manipulating the input signal so that the room curve matches a predetermined target shape, imperfections in (unspecified) loudspeakers and (unspecified) rooms are measured and repaired. It is an enticing marketing story.

      Open Access
      Author: Toole, Floyd
      Affiliation: Retired, Consultant to Harman International
      JAES Volume 63 Issue 7/8 pp. 512-541; July 2015

    13. I have witnessed occasional examples of significant correlation of graphs(measurements) and sonic results. So I worry about those who ignore measurements when they don’t agree with their listening. Purely subjective results are in dire danger of circular reasoning. I like to cite Percy Wilson of Gramophone magazine(decades ago) and the Zanzibar Fallacy.

      I admit strong measurement and sound correlation is rare. But I can cite a few examples I witnessed by a friend, Murray Zeligman, who designed some very good speakers and exotic amplification over many decades.

      I once took him a copy of Hi Fi Choice about 3 decades ago when the magazine would test 30 to 50 examples of one product. In this case it was a cartridge issue. At the bottom of each page was a graph of frequency response, separation and a 1 kHz square wave. He quickly paged through unable to see what was tested and stopped at one page declaring he knew what that cartridge sounded like and he wanted it. It was a Technics EPC 205 MK4. We ordered them and he was dead nuts on. I will add that he had been selling modified Grados and measured what he did to them so he knew what he was looking for. I’m also not sure if he could tell how a less perfect pickup would sound. But he certainly knew what predicted what he thought was a good cartridge. And the measurements were, of course, nice.

      After the start of the century he began to use LEAP to design speakers. I once saw him do a cross over and speaker design with LEAP in a day. I knew after building he would tweak the design. So I asked him how close he could get with the computer. He answered about 95%. In fact he could stop without tweaking but the speaker was slightly colored and since no speaker could be totally uncolored he tweaked the speaker to be slightly colored the way he wanted it. Of course he had decades of experience to use with LEAP. And I’ll add he didn’t really look at the over all response of the speaker but at the response of each driver and it roll offs at each end which, of course, could be acoustical(top of the tweeter), acoustic and box(low end of the woofer) or a combination of driver and cross over(top of woofer, bottom of tweeter, both ends of mid ranges).

      I know we mostly are not at a point where one can design only based on measurements. But I worry about those who ignore all or even some measurements especially when they conflict with what they think they hear. It’s team work. It takes both listening and measuring. And we are losers if we ignore the evidence from either source.

    A stand-off down under: PureMusic vs. JRiver vs. Audirvana+

    Manunta / m2Tech ready Evo Two DDC, clock and PSU