What covid research can teach us about audio measurements.
Recent studies in Canada for patients with so-called long covid show us on how science and measurements and research actually works.
Patients with long covid suffering from limited ability to exercise passed most "normal" tests but it took a new type of test to positively identify a mechanism that explained why the patients suffered.
Honestly there is a lot of snake oil and charlatanism in our hobby, and I don't claim to discount that fact. What I do want to say is that science doesn't rest with 50 year old measurements. It evolves to measure and explain constantly.
The reason I am personally dissatisfied with audio measurements in the common literature is exactly because of this stagnation, and when these fail us we trust our ears and gut for lack of better tools.
Anyone who runs the same 20 measurements on an amplifier or DAC and claims it is science and that these measurements are all that can be known is fooling themselves into believing that they are scientists or that we have reached the limits of understanding.
Few if any of the scientific community doubt the existence of long Covid, and physiological and psychological testing confirms it exists.
The symptoms of ’long flu’ were well established before it became rebranded into a money making exercise of the most unprecedented levels.
What can the audio industry learn from this?
How about starting by creating doubt and fear in the minds of the potential customers? Admittedly the numbers of audiophiles is somewhat smaller than the planets current human population, but that’s just something else to work on as Pfizer have recently demonstrated by seeing off most of their market rivals.
Well, there’s already ’journalists’ already working flat out to create more fear and doubt in the minds of ardent audiophiles. Some of them regularly champion esoteric cables, overkill power supplies, cryogenics, MQA, 180 gram vinyl, cable lifters etc.
Whether the audio industry could go further and try to force all the public to upgrade their systems by mandates is rather unlikely at this point.
Upgrade passports are also somewhat difficult to forsee.
Besides, how many upgrades would you need to be allowed free travel?
One, two, three, four or more?
I believe that even Joe Biden’s speech writers might struggle to concoct any kind of plausible speech for their resident puppet in chief. Undoubtedly some kind of reference to climate change and the war in Ukraine would be involved.
’Your upgrade helps reduce carbon emissions and to fund our, err I mean Ukraine’s troops’ etc etc
Could the entire global media be marshalled into a concerted publicity drive to stress the need to upgrade is also hard to imagine.
Would the Disney owned Marvel Comics go as far as depicting the likes of Spider-Man and Captain America queueing up for high end auditions?
Perhaps what the industry really needs is the likes of Klaus Schwab and the WEF to get behind them.
I don’t think EISA - pause for laughter Expert Imaging and Sound Association - has the same kind of clout that Klaus’s World Economic Forum currently has.
Yes, they could bring in the Great Hi-Fi Reset by the year 2030.
You will own Hi-Fi and You will be happy.
Hmm, sounds noticeably better than their alleged current plan...
A measurement of THD is a measurement of THD. A measurement of frequency response is a measurement of frequency response. To extend those measurements beyond that is not science, it is pseudo science.
I doubt I will make any impact in this discussion as a discussion of measurement takes a level of understanding of several topics that is likely beyond most people participating in this discussion.
Stereophile presents a limited set of measurements.
Audio Science Review presents a more comprehensive set of measurements but are limited in time.
Do engineers and manufacturers do more tests? Some do. Many do not. Many of the tests may not be for sound. For speakers, I expect many small brands don't have the equipment or knowledge for extensive testing, certainly not for speakers.
I wrote a long paragraph but deleted it. I would suggest reading this and coming back: https://www.ap.com/technical-library/using-multitones-in-audio-test/ I don't think this existed 20 years ago or even 15. "The characteristics of a multitone waveform (e.g., spectral content, histogram, crest factor, etc.) give it a much closer resemblance to typical audio program material like music or speech, than a single sine wave"
The speaker testing we do is much more comprehensive. Electronics are nice, predictable, and repeatable (maybe not that SET amp). Distortion normally scales with level, frequency response does not change with levels (it may with load). Nice. Easy. Speakers are nasty beasts. Distortion can be low then rise rapid, and is different at every frequency. Impedance can change with level, which can lead to changes in frequency response (and crossover). Different drivers have different dispersion. Distortion is not consistent across angle. Voice coils heat up leading to parameter changes and passive crossover shifts.
I would spend far less time worried about whether your electronics are tested adequately and spend a lot more time worrying about whether your speakers are tested properly.
Like others have said, I do not see the relevance at least to the arguments in audio. Few if any of the scientific community doubt the existence of long Covid, and physiological and psychological testing confirms it exists. Knowing it exists, they went looking for the cause. You will have to provide strong proof of something in audio that contradicts current scientific understanding in order to get them to chase the cause. I am sure we could come up with 5 or 10 things, medical related, that many people are convinced are true, that the medical community is not chasing, or has chased and debunked. Are not most measurements in audio a simple electrical signal, no matter the source? How much more complicated does it have to get than X = A-B. A = input, B = output. Hardly as complicated as the human body. The other measurements in audio are speakers, and microphones. No one considers those settled science. If they did I would be out of a job. Fortunately I will retire before we have direct brain plug in.
Our brains do a lot of correction, making sound into what we expect to hear, given our experiences. Some day we'll see how hard it works via brain scan. That could be a key measurement in ear fatigue vs relaxation.
My analogy is another sense - Vision. I wear a not unsubstantial prescription that includes near sightedness and astigmatism. With a new prescription or a change in lens material or even just a regrind, first tryout is always disorientation. Peripheral vision is warped with straight lines noticeably curved. After a few days everything appears normal again. That's my brain at work "getting used to it". Tests say I'm 20/20 corrected (or so). That's the measurement standard all prescriptions are judged by. No test measures how hard my brain works to "get used to it" or why everything looks more natural, atmospheric and relaxing when I take off my glasses.
There was a post here a while ago from a psychologist/researcher who aptly collected what I keep trying to say.
A measurement of THD is a measurement of THD. A measurement of frequency response is a measurement of frequency response. To extend those measurements beyond that is not science, it is pseudo science. To take those measurements and discuss "ideal" or the end of all things that can be heard is not science. It is also not science to repeat measurements and rank equipment based on them. That is quality assurance.
It is also not science to lump average human perceptions and claim this is how 1 individual hears.
There is no scientifically agreed to set of measurements which together describe all the human ear/brain is capable of hearing. All we have is a minor number of measurements which are in popular (well, as popular as audio is) culture. I doubt those measurements which Stereophile publishes, are even close to all that is used in modern engineering and development.
As for the rest, caveat emptor, but I won’t hide under the umbrella of science when I’m actually ignorant.
If for instance someone is measuring a cable, or an AC cable, or a USB cable, and
finding "there is no difference in the signal"...and someone wants to say "Actually, you are missing something" it behooves that person to actually explain what they are missing. And if possible suggest how to measure instead.
But if it's all vague hand waving, like "maybe there is something people are hearing that you aren't measuring for"...then what does that give anyone to work with?
How does that help discern nonsense claims from plausible claims?
There is a big difference between doubting science and doubting that measurements tell you what they were never meant to tell you in the first place. Much of pseudo-science actually starts off with some modicum of truth or scientific fact and then goes somewhere it has no right to.
Those absorbed with a handful of audio measurements that are in the public consciousness are very much in this space.
The appeal to the old "science doesn't know everything yet" is one used as a partial justification by every pseudo-scientific/supernatural/fringe belief system.
It's an exceedingly weak justification for believing in dubious ideas.
The patent offices are full of patents for Perpetual Motion Machines by the folks saying "Science doesn't know everything!" It doesn't make claims for a perpetual motion machine an inch more credible. What WOULD make it credible is actual evidence such a machine could or does work! Otherwise you just join the extensive line up of people thinking "I've discovered a new reality" and grumbling about how science just won't recognize their claims.
So, take a conversation I (and others) had with an audiophile who spent over $1,000 on a "high end" HDMI cable to replace his off-the-shelf HDMI cable. He claimed it made the image obviously sharper, obviously richer in color and higher in contrast.
Now...this is literally impossible given how HDMI cables work. He had not upgraded from an old spec HDMI cable to a newer 4K spec'd cable, and hence this was not due to a variable like he was now passing through 4K/HDR images where he wasn't before. The claim was that these were the same spec cables, the original was working, but the new one, as claimed by the company that sold it to him, "improved" the picture quality. It was pointed out this was impossible (unless they had inserted an active chip to alter the image, and didn't tell anyone).
In evaluating such a claim, what is more plausible? That this individual had discovered that the very theory by which HDMI works, the very theory that has allowed the successful manufacturing and deployment of that technology the world over for many years...is actually wrong? Or...given the fact that every human being has the propensity for bias to affect their perception...that his perception was influenced by a bias effect? This is similar to choosing between the likelihood that someone had really made a perpetual motion machine in their garage, overturning basic physical theories, vs their claim being error or bullsh*t.
Nobody makes a dubious claim more likely by crying "But Science Doesn't Know Everything!"
And when you mention "50 year old measurements" that can be a feature, not a bug! If someone wants to say the electronic measurements that have, for instance for cables, been so reliable, and used with predictable results in such a truly vast array of situations around the world...that these ways of measuring are "wrong" or "insufficient" then they take on a substantial burden of proof!
Anecdotes of "I'm sure I heard something" will hardly do! They should at least offer plausible explanations to begin with (and not ones that can be easily undone by someone with expertise in the field) or failing that at least demonstrate that they CAN actually hear this difference they claim.
In other words, can they hear the difference when they are not peeking? In blind tests controlling for sighted bias? That's a component that your OP misses as well. Measurements aren't the only tool in the box. One can indeed demonstrate something can be heard that isn't showing up in measurements. But given the consequences of such a claim, it makes sense to first establish people ARE REALLY hearing this difference, under controlled conditions.
Of course, we can all think we hear whatever we do, and practice this hobby however we want!
But...if someone claims to hear things that are dubious under current theories of electronics and human hearing thresholds, and offers no objective/testable evidence, nor any testable claims (won't show it via blind tests), then they have only themselves to blame for just shouting in to the wind, and placing themselves in the long line-up of fringe theories which also have not passed any of the normal crucibles for reliable knowledge.
Conventional measurement data does not give one ANY meaningful information about the sound of the amplifier (except, perhaps output power). Any company reporting specifications will have an amp whose distortion and noise lie well below the supposed threshold of audibility. Does it matter if an amp has .02% harmonic distortion vs. another amp with half that measure? If, as a subjectivist, you insist on evaluating based on measurements, you have to also accept the extensive research and testing that shows that humans are unable to detect pretty high levels of harmonic distortion, particularly low order harmonic distortion. Levels like 10% or more of 2nd order harmonic distortion is undetectable at certain audible frequencies.
It would be easy for the measurement crowd to win the argument by simply doing an experiment that shows a statistical correlation between measured distortion at the levels seen in consumer amps and either listener preference or even listener ability to distinguish between two amplifiers. i have not seen that demonstrated.
Moderators working under the cloak of secrecy, maybe try and contact so we understand. I read the guidelines, my removed post did not break any of the 'rules',
Agreed. I've always been of the mind to leave everything up for everyone to see and decide for themselves, instead of all of this censoring. It's like they're trying to create a false narrative for posterity.
Good designs will generate the same data, whether DACs, speakers or amplifiers. It's boring because a lot of gear is competently designed, and why it looks repetitive.
If you hook up a computer to two different cars, can the data tell you which car is quieter? More comfortable? Faster? No. What it tells you is that the cars are engineered correctly and you can expect consistent use for a long period of time. That's how I look at measurement data in audio equipment.
For the record, I've never reported anyone. And I never will. I said what I said above because I predicted this thread would go away based on the high level of hostility in some of the postings. I've had complete threads and replies removed for absolutely no viable reason, which most of you I'm sure have experienced. Why completely caustic threads/replies don't get deleted is a mystery to me. No biggie. Let it ride.
Audio measurements are becoming increasingly important as the success of sites like Audio Science Review indicate.
Never in the history of audio has the industry has moved in the direction of less data required.
The equipment and measurements being carried out today were simply beyond the reach of anyone outside of a prestigious physics lab 50 years ago.
What Covid research told us, of course is anyone's guess.
Suffice to say it took an enormous amount of political pressure to get Pfizer to cough up the truth about their Coof jabs.
I would expect more data to follow in due course.
Or, given the stance of the much of the media today, is the correct term "to be leaked?"
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Pfizer Covid vaccine has 1,291 side effects reveals official documents by RT Staff Reporters - March 7, 2022
This release of documents follows U.S. District Judge Mark T. Pittman’s decision on January 6 to deny the request from the FDA to suppress the data for the next 75 years, which the agency claimed was necessary, in part, because of its “limited resources.”
If the moral of the story is science and technology does not stand still, gee thanks Sherlock! Let’s see if this revelation helps convert any knuckle draggers into lesser knuckle draggers.
It really is something else and to your point, I commented on another thread where an Audiogon member wanted someone to setup a fake account on Steve Hoffman forums so they could troll. Guess who’s post was removed? Not the trolls....
I read through many threads and posts before I made my first post and how, to me, can an appropriately moderated forum allow all of these ghost accounts, like the ones I mentioned in my post that still resides in this thread. Yes, you may have guessed I had another post pointing out the absurdity of users with multiple accounts and it was removed.
If the term snowflake applies to anyone, and I hate the use of these stupidly assigned names to certain groups, well it applies to the thin-skinned here who post and then run to mommy moderator when another post makes them feel bad.
You noticed that too? You'll find that some here seem to have an inside track with Admin and get posts they don't like deleted immediately whereas the offensive ones they started with remain up even after being tagged as offensive.
My last two, which were responses to offensive remarks, were removed without email notification from Admin. Talk about a rigged election!
It's like dealing with the Harper Valley PTA on bath salts. They clutch their pearls so tightly, they have waffle patterns on their palms. And, to think, that a lot of the audio community reads these threads but don't dare post here because of them. If they could, this would be a much better place for audio enthusiasts.
Maybe a DM to Tammy can sort things out. The last time this happened, someone else contacted her and she was unaware of just who was doing this.
The article cited by the OP discusses using MRI to visually observe Xenon labeled gases diffuse across the alveolar membrane. It's cool but not a breakthrough. We have been able to measure the same paramater for decades; Diffusion Capacity is a routine part of Pulmonary Function Testing that can be done in any hospital lab.
In audio terms this would be like measuring distortion. Imagine if a new technology came along that could tell you the same thing that old technology already tells you.
Not sure how this relates to any particular topic here. It doesn't begin to tell us if doing measurements are worthwhile, only that there is another way to do them
The problem is the measurements most manufacturers list aren't always that important, if they listed all the measurements it might be a different story.
You may not think that measurements matter but they sure as hell do when anything is constructed.
I certainly have never said measurements don't matter, only that in a scientifically driven world we'd be using new and different sets of measurements as our knowledge and research progressed. That we are still using 50 year old measurements in the common press should be a good sign that more can be discovered.
@johnk People do look at measurements to qualify, regardless of what is written on these pages. Then the subjectivism comes in when making final decisions in the process.
How could you be sure that any audio product matched its prototype without measurements? Don't audiophiles look at measured specs when buying? Or do those who disregard measurements as having any useful meaning just buy on looks and costs? Pretty sure many of those who dismiss are looking closely at published specs when buying.
I do not think people are dismissing measurements wholesale. There are other influences or factors in audio. The ranges are more dynamic.
You can have carefully designed parts and measured parts that can sound awful together in execution. This is the case in any design and in general in engineering, this is why we validate, validate, validate. Design and build is objective, consumption is subjective, meaning there is more bias from the consumer or end user.
Why do those who dismiss measurements in audio not realize that even gear designed without measurements is made up of parts that must be measured and must meet spec? Your hand-built loudspeakers are made of carefully designed and measured parts as are your amps and all things audio. You may not think that measurements matter but they sure as hell do when anything is constructed. Even the plywood and fasteners must meet well-measured specs.
@larryi Thanks for bringing up those measurement metric. I had not heard about them.
(Clearly, a thread does not need to go "poof" just because someone gets triggered and someone else wags their finger. Posters who get back on topic can pull the boat back over and get the keel straight again.)
There have been a few attempts at finding new measurements that better reflect what people hear. For example "transient intermodulation distortion" (TIM) or "slew-induced distortion" (SID) have been put out there to measure distortion caused by an amplifier's inability to respond quickly enough to abrupt changes in the signal level. This is a particularly interesting measurement because, in an attempt to reduce more conventional measurements of distortion, such as harmonic distortion, amp manufacturers may employ a lot of feed back. Feedback adversely affects TIM/SID measurement. I tend to not like amps that employ a lot of feedback so, perhaps, this less common measurement might have some meaning.
Anyway the analogy doesn’t make sense to me. They weren’t measuring the MRI machine.
Think of medicine, and that doctors and researchers repeatedly break into two camps. One camp always looks for more information and more ways of looking at disease.
Another group gets into a cycle of believing something is true, and that all that can be learned has been learned, until some new technique or tool comes along which forces a change.
Two instances I can think of is polio treatment and gastric ulcers. At some point we thought ulcers were caused by stress. For decades. Only in the late 1980s did a pair of curious pathologists come to discover it’s often caused by bacteria.
Audio measurements, those in the common publications (Stereophile, TAS, Hifi+, etc.) have been more or less stagnant for solid state devices for decades. Of course researchers may be working on more, or use more which we don’t hear about. Audio Precision has an R&D department, but how long has it been since we in the lay readership/press have heard of a new type of measurement which means something to a listener? Not more precision for old measurements but actually new measurements?
This is why medicine is a good analogy. Let’s not get stuck thinking measurements assembled 50 years ago are all that could be known.
Trying to compare our hearing to any modern scientific measurement tool is folly to the Nth degree. Most audiophiles have no idea what they are listening too. They throw their systems together without measurement so they have no basis for comparison. If you are use to listening to a system that is boosted above 8 kHz a flat system will sound dull even though it is more accurate. If you are under the illusion that your system is flat it might be, but the room is probably not. Obviously everyone is entitled to set up their system any way they want but don't bark at me when I squint.
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