[Blanchot]

The only escape is if you realise the information is at least questionable AND you're not "all good with marketing and group think" AND you can be bothered to spend a considerable amount of time locating and understanding the applicable areas of scientific research and engineering going back over a century. The vast majority either do not fulfil any of these conditions or only fulfil the first and/or second, extremely few can be bothered to fulfil the last one!

Suppose someone would like to do that, where would he even start? The task seems so huge that it's likely to discourage even the most sincere thruth seeker.

 

[Blanchot]

Me too! I've been engaging on and off with the audiophile community for about 15 years and after all that time I'm well accustomed to all the marketing BS, but I'm still taken aback by the sheer amount, width and depth of it all. I should mention that I have an outside view, I've been a professional recording and sound engineer for nearly 30 years and instructed others at university for a number of years, which is what enables me to spot the audiophile BS. Although some of it can be very sophisticated and even I have to go and research it.

I understand why the extent is so great, there's really no other option. DACs and amps were perfected (within the limits of audibility) decades ago and even a couple of decades ago could be audibly perfect at very low prices, what are audiophile manufacturers/retailers to do? There's really only two choices, make-up nonsense problems which your new DAC fixes and therefore sounds like the "next level" or, go bust. We've got to the stage now, where it's just nonsense piled on nonsense, all joined together with circular logic, other logical fallacies and denial of even the most well proven/established scientific facts.

G

Are you saying that when some people claim to prefer DAP A over DAP B because the former has R2R and the latter AKM or ESS or whatever then they are fooling themselves? Right now there is a lot of buzz over the first DAP to use ROHM chips and everyone is eager to hear how it sounds.

 

[gregorio]

Suppose someone would like to do that, where would he even start? The task seems so huge that it's likely to discourage even the most sincere thruth seeker.

Well yes, it is huge and daunting because we're dealing with several different scientific fields, electrical engineering/electronics, DSP/Software development and music. You would probably need to spend decades studying each of them if you wanted a really in depth understanding, so it's not just discouraging, it's near impossible. However, subforums like this can help, there's more than a fair amount of combined knowledge here and we can usually explain most of what you might want to know in layman's terms, plus there are other forums such as Hydrogen Audio with even deeper knowledge. Of course, just believing what some random guys on the internet are telling you, regardless of their "authority", is what we spend a lot of time trying to combat in this subforum, so it would be hypocritical to suggest you believe us random guys rather than other random guys in say the Cables subforum. The difference in this subforum is that we must be able to back-up what we're asserting with objective measurements and tests and/or by reference to scientific research/studies or principles. IMHO, the best way to start is just to start asking questions and if there's anything that seems wrong or dubious, ask for reliable supporting evidence. As a primer, I would suggest a visit to wikipedia and reading up on the scientific method.

Are you saying that when some people claim to prefer DAP A over DAP B because the former has R2R and the latter AKM or ESS or whatever then they are fooling themselves?

Yep, it's pretty much certain they're fooling themselves. This being the sound science forum though, I can't just make a claim without reliable supporting evidence, which I don't have because I haven't measured DAP A and DAP B. However, I do have some pretty compelling circumstantial evidence:

1. The performance of the standard Delta/Sigma converter chips by ESS and the other chip manufacturers is published/verified. They perform way beyond the threshold of audibility (IE. They're all audibly perfect, by a large margin) and have done for many years.
2. At the highest end, R2R is also capable of performing way beyond the threshold of audibility. However, it's more difficult and much more expensive to achieve the same level of performance as standard mass produced D/S chips. We therefore tend to find that R2R DACs have poorer performance than D/S DACs, although still beyond the threshold of audibility.

According to the above evidence we would have to conclude "they are fooling themselves" (or being fooled by marketing) because the performance and therefore differences between R2R and D/S architecture are inaudible. However, as R2R is more difficult to implement and to a certain extent is a "custom build", there's more opportunity to screw it up big time and achieve performance that is not beyond audibility. Additionally, the R2R architecture allows for an implementation called "NOS" (Non-OverSampling/filter-less), this ignores fundamental requirements of digital audio and could be described as "deliberately screwing it up very big time", and this is well within the threshold audibility. This is why I stated "it's pretty much certain" rather than just saying "it's certain"; they shouldn't and most probably do not sound any different but without measuring them we can't be absolutely certain they haven't really screwed up the R2R implementation (unless they state it's a NOS implementation).

NB. I'm only talking about the basic architecture here, there are other considerations that can/does cause audible differences between DAPs, it's player/DSP software for example.

Right now there is a lot of buzz over the first DAP to use ROHM chips and everyone is eager to hear how it sounds.

Oh dear! In the audiophile world with digital audio products, it's typically safe to assume that: "Lot of buzz over ..." = "Priming for placebo effect".

G

 

[Blanchot]

To make the task more manageable, is it possible to give some hints/literature tips on how to get an understanding of measurements and how to evaluate them critically? For the record, I'm heavily into the portable side of the hobby, so headphones, IEMs and DAPs are my primary interests.

I'm at the point where I I'm satisfied with the setup that I have. I see no reason to add another component to my collection but I would like to have a deeper understanding of the technical side of things.

 

[gregorio]

To make the task more manageable, is it possible to give some hints/literature tips on how to get an understanding of measurements and how to evaluate them critically? For the record, I'm heavily into the portable side of the hobby, so headphones, IEMs and DAPs are my primary interests.

The Innerfidelity site was useful for HP measurements. It's closed down now but is all archived by Stereophile, here's the page that explains HP measurements, which is a good place to start. When you have more questions about this or DAPs, it would probably be best to start a new thread in Sound Science.

G

 

[bigshot]

I started a thread with info and discussions on thresholds of human hearing as they relate to the various specs listed on equipment. You might find that helpful too. https://www.head-fi.org/threads/the-most-important-spec-sheet-the-human-ear.645851/

 

[Blanchot]

I started a thread with info and discussions on thresholds of human hearing as they relate to the various specs listed on equipment. You might find that helpful too. https://www.head-fi.org/threads/the-most-important-spec-sheet-the-human-ear.645851/

The Innerfidelity site was useful for HP measurements. It's closed down now but is all archived by Stereophile, here's the page that explains HP measurements, which is a good place to start. When you have more questions about this or DAPs, it would probably be best to start a new thread in Sound Science.

G

Big thanks to both of you! This sub-forum is a friendlier place than I first thought given it's reputation

 

[Redcarmoose]

Expectation bias/Placebo are not real but in medical terms the results are real.

Participants in placebo groups have displayed changes in heart rate, blood pressure, anxiety levels, pain perception, fatigue, and even brain activity.

So in a sense the audio equivalent to placebo could in fact exhibit real phenomenon. The problem though is it can’t always be replicated!

What is fascinating is the latest Chinese brand fiasco. Supposedly a bunch of IEMs had fake drivers. So what was marketed as a Hybrid IEM was in reality a single DD. It is amazing now how many have distanced themselves from the products (they own) even though the sound identical as before.

 

[bigshot]

Big thanks to both of you! This sub-forum is a friendlier place than I first thought given it's reputation

Our rep is from not suffering fools gladly. Regular folk get along fine here.

 

[gregorio]

This sub-forum is a friendlier place than I first thought given it's reputation

If someone comes here and tries to pervert science by repeatedly asserting false marketing is fact, then we do tend to become somewhat unfriendly. If you're not sure about how this audio stuff works and ask questions politely, then we're entirely friendly and more than willing to help.

It probably has it's reputation because this is just a subforum of a larger site that's dominated by false marketing and those who believe it, so a number of them seem to feel it's necessary to come here to defend or validate their beliefs by picking a fight against "science". Unfortunately, this sort of thing seems to be becoming far more widespread and common in other areas.

G

 

[gregorio]

Expectation bias/Placebo are not real but in medical terms the results are real.
Participants in placebo groups have displayed changes in heart rate, blood pressure, anxiety levels, pain perception, fatigue, and even brain activity.
So in a sense the audio equivalent to placebo could in fact exhibit real phenomenon. The problem though is it can’t always be replicated!

Agreed, except for the last two sentences. Placebo in audio is not a real phenomena but it can result in real physiological effects and real experiences or impressions. The biggest problem IMHO is that so many falsely believe it is a real phenomena.

G

 

[castleofargh]

To make the task more manageable, is it possible to give some hints/literature tips on how to get an understanding of measurements and how to evaluate them critically? For the record, I'm heavily into the portable side of the hobby, so headphones, IEMs and DAPs are my primary interests.

I'm at the point where I I'm satisfied with the setup that I have. I see no reason to add another component to my collection but I would like to have a deeper understanding of the technical side of things.

1/ if 2 graphs weren't done by the same guy, DO NOT try to weight up their differences to find some meaning.
2/ FR is usually the most relevant variable in term of listener's preference. And you should not look at one graph, but put 2 side by side with one from an IEM you own and know. Then you can make some educated guess about how the other one with more bass here and less 4kHz, might be something you'd like(or not). Trying to play around with an EQ on the IEM you own might also help get some idea of what you like, but also let you experience directly how it feels to you when you move the amount of EQ at a given frequency. It helps realizing how 80Hz is already very low for our ears, while most people who have zero training with test tones or EQ, will hear 800Hz and think it must already be in a treble. IMO getting familiar with that is the most important first step. Being able to put a value on a tonality will really help you communicate but also pick stuff you like more easily.

THD is mostly irrelevant. If you see stuff getting above 1% in the midrange, then it might be a good idea to look for another IEM, but otherwise, THD at large doesn't correlate well with listeners' preferences.
Some other distortions measurements happen to work better as a measure of sonic preference, but you will basically never see such measurements, so just forget about it. There are a few papers on the topic if you wish to learn about something you will never have a use for.


As you're into DAPs and IEMs, you will at some point have to bother with impedance. I tried giving some simple examples on why we shouldn't assume that one experience fully defines the sound of an IEM or a DAP here https://www.head-fi.org/threads/feedback-about-gears-stop-doing-it-wrong-impedance.866714/ and of course if you're into that, there is https://www.head-fi.org/threads/headphone-amp-impedance-questions-find-the-answers-here.607282/ with ohm's law and all that. Less specific to IEMs and DAPs, but very much in line with physics, so it can always be useful.
You may also have to consider looking into the acoustic of the human ear, But I can already spoil the ending: we're all hearing things differently. Some things are very similar for everybody and some just aren't, depending mostly on the shape of your body.


And of course, the 2 big ideas to always keep in mind:
Humans, like any sensory system, have limits. Hearing thresholds are a thing.
And as a result, magnitudes do matter. Everything has noise, everything has some amount of distortions, only the magnitude separates the meaningless inaudible stuff from what we should actually care about.
Those 2 very clear and very obvious ideas should, once you fully accept them as factual, let you facepalm about a dozen times a day while reading an audiophile forum. I'd say that's when it starts happening and you're screaming "dude, do you even magnitudes?" at your screen, it's a sign you're on the right track.


There are tonnes of papers on psychoacoustics that are more or less relevant to deciding what matters in a measurement, and because we've been learning a lot in the last decade, I would argue that such papers are better than some classic book on the topic. But unless you're into that, it's a lot of efforts to mostly improve your ability to doubt and say "IDK". Even if you're interested, on the web there is this weird situation where most papers are behind a paywall, but at the same time, if you contact the writers of the paper by mail, they're almost always very happy to provide it to you for free. I get hysterical anytime I see knowledge being withheld for BS reasons so I won't say more at the risk of having to moderate myself.

edit: for spelling, punctuation, and whatever kind of stroke I had on the first draft.

 

[bigshot]

Thankfully, distortion generally isn't as much of an issue with headphones and IEMs as it is with speakers. I don't think distortion has any impact at all with headphone listening in most cases.

 

[gregorio]

I get hysterical anytime I see knowledge being withheld for BS reasons so I won't say more at the risk of having to moderate myself.

I "liked" your post but I'm not so sure about this bit. Sure I get a bit frustrated now that I don't pay and have lost my free access to all the stuff behind paywalls. On the other hand, I appreciate the higher confidence provided by having papers peer reviewed by a number of independent, qualified experts. Such experts aren't cheap and that cost has to be recouped somehow.

OP: Sorry, we've gone a bit off topic. I also noticed that we've mostly talked about when placebo is not a good thing but besides the mention of perceiving the stereo illusion, not much else about when it is a good thing. So here's an example to balance the thread a bit, although this perceptual error is more a sort of inverse placebo, not hearing something that is real and easily audible:

You often see audiophiles adamantly proclaiming and instructing others to listen and trust their ears. Apparently they don't seem to realise that if we actually did that, then we would have no choice other than to conclude that most of the time we are dead! During times of anxiety (fear or pain for example) we can sometimes hear our own heartbeat, very loudly on occasion, but what about the rest of the time, when we can't hear it at all? Our heart does not beat at inaudible levels and then suddenly output ~10,000 times more sound when we feel pain or fear. So if we trust our hearing we must believe our heart is not beating when we're not anxious. Science has long theorised that we can't trust our hearing, that there must be some process in the brain that suppresses/filters out the sound of our own heartbeat from our perception. These theories started becoming more sophisticated about 50 years ago as more evidence was discovered but it's only recently that Swiss scientists discovered the part of the brain actually responsible for this filtering effect (the insular cortex) and something about the mechanism. The full published paper is here and a brief description is here.

This (sort of) placebo effect is obviously a good thing. Firstly, hearing our own heartbeat has itself been demonstrated to cause anxiety and secondly of course, it would be far more difficult to hear quiet noises (that may indicate danger) if you're hearing a loud thumping all the time. Incidentally, our heartbeat isn't the only thing we hear but is filtered out of our perception, blood moving through blood vessels near the ear is one of several other examples. There's also what is often referred to as "the cocktail party effect", which is suppression of purely external stimuli/sounds. The reduction of other people's voices (say at a noisy cocktail party) when trying to hear one particular voice.

G

 

[Redcarmoose]

Have you ever witnessed a true audiophile get ready for a listening session? (The person I’m referring to is not me, I primarily just take a pair of IEMs out of their airtight case and plug into a DAP.)


The audiophile:
They start by mixing a small drink, normally about a shot or shot and a half of 80 proof alcohol. They next make their way into the listening room and shut the door. The lights are only half-way on (darkness increases audio perception). They make a phone-call downstairs as to not be bothered for an hour or two. Luckily the person on the other end of the line is supportive of this endeavor!

Next the two tube amps get turned on. Next the powered subs X2 get turned on. The preamp gets turned on. The turntable speed controller gets activated. Next the turntable get uncovered. Now as everything is in warmup mode the record gets selected. Holding his head sideways in the dim light the audiophile is now reading the record sleeves. Finally he comes to that rare limited pressing of “Houses Of The Holy”. It’s a pressing few even know existed. A limited test run right before Jimmy Page himself put the halts to it, so he (in-fact) could make his own by remastering the tapes.

The room gets silent as the audiophile slowly pulls the record out. The record rolls out into his hand and he turns to the record cleaning machine. As the record is being spun for cleaning he reaches over and clicks on the $10,000 phono preamp. All is well and their is a brisk feeling of excitement which seems to fill the room. The record comes off the cleaning system and is finally carefully placed on the turntable platter. Yet before it starts to spin an anti-static brush is pulled across it. Then the outer weight ring is placed in hold the outer edges down. Next a center clamp is screwed down on-top of the vinyl center. Next the turntable is turned on directly after making sure the cable system was lightly dusted with special traction dust. The spinning starts, next the RPMs need to be specially calibrated. Slowly an RPM too slow, and RPM too fast........then it settles in. 33.3 RPM all is well!


All is go as the needle gets finally put into place after removing the protective needle cover. The needle is in place and tracking into the beginning of the song.

The sound starts and volumes get a last minute adjustment. A chair is already in place in the zone. He sits back after grabbing the drink, and closes his eyes........


This is placebo in the making. It may not be real, but it can be created!