Resolve's B&K 5128 Headphone Target - you can try the EQ's.....

[Mad_Economist]

As far as headphones Sean Olive adressed the issues BK5128 not offering an improvement in representing human subjects :

You'll have to pardon the dual reply, I didn't see your edit.

To some extent, the 5128 not being more accurate in Sean's test there is a tautology - the only respect where it is demonstrably more accurate is in ear Z, and those tests were blocked canal, which, necessarily, cancels any effect of system ear Z.

If you want to make the argument that ear Z is not a major factor for circumaural headphones, we're on the same side! I have long been of the position that blocked canal measurements are a quite good approach (and have talked to people about it on this forum for over half a decade now!).

 

[Robbo99999]

The stock RED tuning has always been my ideal. The Bass+ adapter was included just in case consumers did indeed prefer a higher bass shelf (because there were so many armchair objectivists complaining that it was going to be too little based on early measurements), but at the end of the day it seems that the vast majority of users prefer it stock.

https://twitter.com/i/web/status/1675052171933671429

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Just as I had tuned it from the very beginning.

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Based on my experience of headphones tuned to Harman & Truthear Blue, I would think the Truthear Red would indeed sound better without the bass adapter due to the treble not hitting Harman IEM, therefore having "deficient bass" helps equal out the tonality with the "lack of treble".

 

[Mad_Economist]

Based on my experience of headphones tuned to Harman & Truthear Blue, I would think the Truthear Red would indeed sound better without the bass adapter due to the treble not hitting Harman IEM, therefore having "deficient bass" helps equal out the tonality with the "lack of treble".

This generally agrees with my understanding of Sean's take on Lorho's findings: to some extent, "less treble" and "more bass" seem to be substitutes, albeit imperfect substitutes.

 

[Robbo99999]

This generally agrees with my understanding of Sean's take on Lorho's findings: to some extent, "less treble" and "more bass" seem to be substitutes, albeit imperfect substitutes.

Fair enough, that's good, I was just basing it on my intuitive understanding combined with my experience of EQ'ing my headphones, good that it matches some research!

I found the Truthear Blue to be very pleasant at stock, and slightly improved with EQ to Harman 2019 IEM to remove a small amount of shoutiness over longer listening sessions, but the EQ boosted subbass slightly & also reduced the shoutiness region slightly, so I could infer that for me the Truthear Red with bass adapter would be too dull given that it's treble region is already depressed vs Harman 2019 IEM, whereas Blue was slightly above Harman IEM to start with.

Yep, well we understand eachother!

 

[crinacle]

Based on my experience of headphones tuned to Harman & Truthear Blue, I would think the Truthear Red would indeed sound better without the bass adapter due to the treble not hitting Harman IEM, therefore having "deficient bass" helps equal out the tonality with the "lack of treble".

This generally agrees with my understanding of Sean's take on Lorho's findings: to some extent, "less treble" and "more bass" seem to be substitutes, albeit imperfect substitutes.

Yep, that was the philosophy behind the tuning! Harman research also confirms that user preference toward the magnitude of bass boost and the magnitude of downslope generally tracked each other well (users who preferred more bass generally tuned for more treble, and those preferring less bass also generally tuned for less treble). Vilifying the subset of users who deviate from preferring the Harman Target(s) runs completely counter to the principles that formed the foundation of its research, which is again, user preference.

 

[Mad_Economist]

Yep, that was the philosophy behind the tuning! Harman research also confirms that user preference toward the magnitude of bass boost and the magnitude of downslope generally tracked each other well (users who preferred more bass generally tuned for more treble, and those preferring less bass also generally tuned for less treble). Vilifying the subset of users who deviate from preferring the Harman Target(s) runs completely counter to the principles that formed the foundation of its research, which is again, user preference.

It's a shame that so few companies follow the advice from Factors That Influence Listeners' Preferred Bass and Treble Levels in Headphones' conclusion

 

[GaryH]

The stock RED tuning has always been my ideal. The Bass+ adapter was included just in case consumers did indeed prefer a higher bass shelf (because there were so many armchair objectivists complaining that it was going to be too little based on early measurements), but at the end of the day it seems that the vast majority of users prefer it stock.

https://twitter.com/i/web/status/1675052171933671429

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Just as I had tuned it from the very beginning.

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So the Red's stock response you targeted with your tuning is 'ideal', and you claim the 'vast majority' prefer it, yet it falls way short in the bass of your target you use on your own site? Doesn't make any sense. The stock Red still has a significant bass shelf above headphones.com's target anyway:

So obviously as I said even you realize their target is far from ideal and needs a bass shelf.

Vilifying the subset of users who deviate from preferring the Harman Target(s)

Who's doing that? Vilifying you say? You mean language like this, on headphones.com's latest Take the Red Shill video (I've lost count how many we're up to now), calling Harman IE "garbage"? And denigrating Dr Olive's scientifically controlled research with comments like this:

All I need to do is to cite is the title of research that went into developing IE 2017 2016...Respondents in this study (if you can even call it that)

Yet the 'evidence' (if you can even call it that) you present in contrast consists of internet polls of anecdotal impressions of uncontrolled sighted listening? And restricted to your ardent fans on Twitter/YouTube at that? Hilarious.

runs completely counter to the principles that formed the foundation of its research, which is again, user preference

As a proxy for perceived neutrality. The real underlying principle that formed the foundation of Harman's research was breaking audio's circle of confusion by finding a common standard default headphone frequency response that is perceived as neutral/preferred by the majority, based on simulating the sound of good speakers in a good room which are what music is mixed and mastered to sound best from. All you and headphones.com are doing with this 5128 pseudoscience is perpetuating the circle of confusion with your multiplicity of made-up untested targets using a rig that has not provided any direct proven correlation with preference whatsoever, let alone the promised improvement over GRAS and Harman's targets.

 

[markanini]

Except that it...isn't, as a generalization, which is what I was responding to. It's true that some 60318-4/711 configurations give greater precision in insertion depth, but that's not the case with the anthropometric ear canals, and indeed more true-to-life fitting was part of GRAS' sales pitch for them.

Something I was attempting to be vaguely oblique about but will now state directly is that being unable to force unrealistic insertion depths is not a bug, it's a feature. It's true that it would be preferable to have a variety of canals (different type 4620 pinnae when, BK?), but if you have one, having it realistically interact with the geometry of the actual device is preferable. If you want to look at the length mode damping behavior alone, you're better off omitting the parallel resonators and using a .4cc.

Which has to be a moot point, because IEC 711 encompasses a multitude of options that can be chosen according to ones needs, many are highly modular. No need to attempt re-framing any limitation as a feature.

Again, I was was dragged into discussion where the other party expected me to accept the new rig has a higher accuracy "a priori". Except this could not be verified due to basic limitations of the system. Maybe if the IEC711 measurements were redone to match the insertion depth forced by 5128, then meaningful deltas can be calculated.

Again, I'm not the guy pushing a new measurement system down peoples throat. I'm only asking simple consequential questions, it shouldn't generate a flurry of special arguments, or apparently bad blood on Discord. That tells more how highly invested those pushing it are, than the possible perks of the system.

 

[Mad_Economist]

Which has to be a moot point, because IEC 711 encompasses a multitude of options that can be chosen according to ones needs, many are highly modular.

The point is not moot because @crinacle and @Resolve's warnings about such cross-comparison apply also to a measurement of IEMs conducted with the KB500x or KB501x pinnae - this would include, as far as I am aware, @amirm's measurements of IEMs. Again, measurements seated in an anthropometrically accurate canal are from my POV preferable for realistic results, so I'm in favour of using the KB5010/KB5011 for IEM measurements with 60318-4s.

Again, I was was dragged into discussion where the other party expected me to accept the new rig has a higher accuracy "a priori". Except this could not be verified due to basic limitations of the system.

Please do not let me "drag" you anywhere, and I think that given the circularity of this discussion it's quite pointless to continue rehashing this further, but the higher accuracy is empirically demonstrated by Søren's much-linked-to measurements of actual human ear Z. This is what we mean when we say it is more accurate, and it is demonstrably more accurate in this capacity. Nothing about the 5128 or indeed any part of ITU-T P57 Type 4.3 or 4.4's prescriptions limit us from establishing this fact, and in the absence of countermanding evidence, it is the state of the literature as it presently exists.

You may prefer to use the word "accuracy" differently - ultimately, that's your prerogative, but please do not misconstrue what is being said to you using a well-established definition which has been retreaded here several times.

Maybe if the IEC711 measurements were redone to match the insertion depth forced by 5128, then meaningful deltas can be calculated.

Ironically, Søren's paper already establishes a methodology that avoids the need here - that, indeed, is what the whole "propagation" business in said paper is about.

Again, I'm not the guy pushing a new measurement system down peoples throat. I'm only asking simple consequential questions, it shouldn't generate a flurry of special arguments, or apparently bad blood on Discord. That tells more how highly invested those pushing it are, than the possible perks of the system.

This image is, generally, what the concept that the 5128 is being pushed down people's throats makes me think of It's a quite sparingly referenced device even in the world of enthusiast audio, and you really have to go out of your way to run into claims made about it on a regular basis. Certainly, Headphones.com intends to keep publishing measurements and commentary based on the 5128, and I'd imagine @crinacle does as well - does that constitute pushing things down people's throats? I suppose we could make a 5128-free viewing mode for the site where only 43AG and 45CA measurements were visible, but that seems like it has a pretty niche audience

I'm not sure what you find particularly special about my arguments (perhaps you're referring to somebody else's?), but all I am trying to do in commentary about the 5128 is the same as in discussions of audio measurements in general: represent the state of the lit as I understand it, and my personal opinions as they exist.

I had no idea what you mean about Discord, but on checking, it looks like you were banned from the headphones.com discord for harassing one of our mods on a different server.

 

[Merkurio]

I have no problem whatsoever with changing the standard of measurements to one that is more accurate and more in line with the purpose for which it was developed (a better representation of human hearing), after all that is the purpose of improving in all fields of knowledge and acoustics were not to be outdone.

Nevertheless, and from my narrow perspective as a mere aficionado (who values the importance of the graphs as a mere approximation of what will finally reach my eardrum), I consider that the robustness of the targets developed based on GRAS systems outweighs (for now) the added accuracy that B&K systems can provide, at least until they're not on equal terms to be used for EQ purposes.

In that sense, I think it wouldn't hurt to have a disclaimer telling people that the measurements done using GRAS systems are (to date) more robust to use for EQ headphones, while the B&K ones are a more accurate (state-of-the-art) systems to better represent the FR of the same headphone (although I insist, without a familiar target like the Harman that serves as a compensation, we are in the same blind spot regarding to the increased accuracy it provides).

Just my opinion as someone who does not see things from the same technical stature as you do guys.

 

[amirm]

Certainly, Headphones.com intends to keep publishing measurements and commentary based on the 5128, and I'd imagine @crinacle does as well - does that constitute pushing things down people's throats?

Pretty much.

 

[lazarian]

I would say that as two of the largest providers of measurements, especially in Crins case, yeah that's a huge impact on the measurement community. We're left to make use of the new targets, or rely entirely on Oratory if Crin isn't providing 711 measurements. Of course it does seem like 711 measurements will continue to be posted by hp.com, unsure what Crin's plans are though.
Probably good for Oratory to get more people aware of his services though anyway, he does amazing work for us all.
There is the counter though that having more measurements from multiple reputable rigs can lead us to a better place. Comparisons can be done, people can hopefully via things like autoeq generate eq's and hear for themselves what they prefer.
In the background we hope the big industry players are furthering the science as well. If we start seeing a bunch of headphones that measure differently from previous Harman research coming from them... then we can definitely assume they've got some good new research, even if its not published.

 

[markanini]

I had no idea what you mean about Discord, but on checking, it looks like you were banned from the headphones.com discord for harassing one of our mods on a different server.

Overzealous mod behavior on IEF Discord is a bit of a meme: https://rohsa.gitlab.io/articles/quit-ief-and-stop-updates/

On the other hand, maybe before charging me of abusive behavior @_listener_ , mod of In-ear Fidelity and Headphones.com Discord server, can first explain why he chooses to come out of left field and and dispute a subjective sound impression I gave of an IEM product. Arming himself with, would you guess, BK5128 measurements.

And he can explain why he choses to continue pursuing me, after me telling that I didn't seek an argument, reassuring that I was a subjective impression I shared, not meant to be compared with measurements of any system.

 

[Mad_Economist]

I would say that as two of the largest providers of measurements, especially in Crins case, yeah that's a huge impact on the measurement community. We're left to make use of the new targets, or rely entirely on Oratory if Crin isn't providing 711 measurements. Of course it does seem like 711 measurements will continue to be posted by hp.com, unsure what Crin's plans are though.

It would surprise me immensely if Crin stopped measuring things on his IEC711 - he has never said he plans to do this, and mentioned the cost of maintaining and updating two separate databases as part of why his patreon tier pricing changed a bit (not that he needed that justification). I think you can rest assured that nobody with older couplers is planning to throw them away or stop posting data from them

Probably good for Oratory to get more people aware of his services though anyway, he does amazing work for us all.

Well, better or worse - @oratory1990 doesn't make any money on measuring stuff, and it takes a lot of his time. I'm always glad to see him getting the appreciation he deserves though, absolutely one of my favourite people in this whole community.

I have no problem whatsoever with changing the standard of measurements to one that is more accurate and more in line with the purpose for which it was developed (a better representation of human hearing), after all that is the purpose of improving in all fields of knowledge and acoustics were not to be outdone.

Nevertheless, and from my narrow perspective as a mere aficionado (who values the importance of the graphs as a mere approximation of what will finally reach my eardrum), I consider that the robustness of the targets developed based on GRAS systems outweighs (for now) the added accuracy that B&K systems can provide, at least until they're not on equal terms to be used for EQ purposes.

In that sense, I think it wouldn't hurt to have a disclaimer telling people that the measurements done using GRAS systems are (to date) more robust to use for EQ headphones, while the B&K ones are a more accurate (state-of-the-art) systems to better represent the FR of the same headphone (although I insist, without a familiar target like the Harman that serves as a compensation, we are in the same blind spot regarding to the increased accuracy it provides).

Just my opinion as someone who does not see things from the same technical stature as you do guys.

One note here, and probably why that isn't likely (although we may put on a disclaimer that achieves that same effect?), is that EQing by sight on graphs isn't something that I, or to my knowledge anyone at headphones.com, is generally recommends. Headphones interact with the circumstances of being worn (leakage and positioning) and the individual listener's ear in somewhat dynamic ways, and while a graph from a 5128 or 43AG may be a useful starting point for EQ experiments, they should definitely be mostly refined by listening.

Indeed, something we're rather excited about with having multiple heads - and which @Resolve has mentioned several times - is comparing the differences between headphones across systems. It's something of an "X factor" at the moment how much stability of tone/perceived response/timbre is across individuals varies across different headphone designs, and it'd be interesting to put some data to that question.

 

[Merkurio]

One note here, and probably why that isn't likely (although we may put on a disclaimer that achieves that same effect?), is that EQing by sight on graphs isn't something that I, or to my knowledge anyone at headphones.com, is generally recommends. Headphones interact with the circumstances of being worn (leakage and positioning) and the individual listener's ear in somewhat dynamic ways, and while a graph from a 5128 or 43AG may be a useful starting point for EQ experiments, they should definitely be mostly refined by listening.

Oh, absolutely.

I never ―or almost never― rely solely on the preset, whether it is from Oratory or generated with the AutoEQ tool on the Crinacle website (or the same frontend on Squig), I always use them as a starting point because I know that there is no absolute accuracy with the results of these measurements due to a multitude of variables (related to the measurement rig itself, the headphones and my own HRTF), then I make fine adjustements here and there using pink noise, sine sweeps and my own well-known music until I'm satisfied.

My issue with the 5128/4620, aside from the limited number of available measured models, is that the proposed DF target does not serve me as a reference point in the same way that the Harman target does for IEC 60318, at least in the headphone models I've tested that have measurements available for both systems (with the Sennheiser IE300, which have measurements for both systems and are IEMs, I have had to spend much more time to achieve acceptable to "good" sound using the DF target with the B&K, so it's definitely not worth it for me, at least for now).

 

[amirm]

Please do not let me "drag" you anywhere, and I think that given the circularity of this discussion it's quite pointless to continue rehashing this further, but the higher accuracy is empirically demonstrated by Søren's much-linked-to measurements of actual human ear Z. This is what we mean when we say it is more accurate, and it is demonstrably more accurate in this capacity.

No, that is not what you say. What you want people to think is that the measurements more accurately predict listener preference. There is not a single soul that cares about the impedance matching of the measurement rig against a study. That is of no value to them. They want to know how a headphone sounds. But going with the flow, this is the comparison of the mean impedance in that population study against the 711 coupler:

As the study authors state, the response is with one standard deviation until about 12 to 13 kHz and gets worse around the anti-resonance of 15 kHz. The deviations below this are actually fully compensated for in Harman's research as it applies to our application: listener preference. If a fixture like 5128 mimics the above, then it is the outlier (in green), not the 711. That deviation is non-linear and hence the reason it has been easy to show that the Harman target doesn't work for 5128.

What you have to also keep in mind that the above are under strict laboratory protocol. There is no way a reviewer is going to be able to assure compliance with their protocol. Indeed, even the authors of the study failed to do that for their full set of volunteers: "A total of 44 subjects entered into this study, but 12 were rejected because reliable measurements could not be obtained." That is nearly 30% exclusion!!!

Read again: they could not get repeatable results with nearly 30% of the volunteers they had. The study results have also not been confirmed or repeated.

So no way you want to run with the punchline like you are using. As I have repeatedly stated, the claim of accuracy here is a marketing one looking for verification.

We have what we need with 711 fixture. Good correlation with listener preference up to pretty high frequency above which, is anything goes anyway.

 

[Mad_Economist]

No, that is not what you say. What you want people to think is that the measurements more accurately predict listener preference. There is not a single soul that cares about the impedance matching of the measurement rig against a study.

I have no idea of whether there is a statement I, or Headphones.com, or whomever you're indicting here can make to dispel this idea, but I'm going to try anyway: No, what I want people to think is that the 5128 is more accurate in its approximation of human ear impedance. This is because the 5128 is more accurate in its approximation of human ear impedance. I have repeatedly, at substantial length, on this forum and others said that I don't think acoustic Z is particularly important for circumaural headphones. This makes sense from both a math standpoint and from my own measurements comparing occluded canals and DRP measurements. I have said this over and over, and will continue to say this over and over, and ironically I have continuous (friendly) arguments with @oratory1990 about it (with him in favour of more accurate Z as a necessity).

For in-ear designs, there's a quite reasonable case to be made that the 5128 provides more accurate results to human perception. Ironically, the main area where this would be the case is the low frequencies, where the 5128 matches the human ear's impedance more closely, as opposed to the trumpeted-about improvements in the 8-20khz band. In practice, how significant this is will depend on acoustic Zout of the earphones in question, which is natural since we're talking about the pressure level in the canal.

Are these fairly small points? Yes, absolutely. Is the 60318-4 standard still as useful as ever it was (which was quite useful indeed) for measuring headphones? Yes, absolutely. Is anyone coming to confiscate all the 43AGs and 45CAs? If they are, it won't be anyone affiliated with me. It's surreal to me that conducting measurements on a standards-compliant measurement system has become offensive to you here.

As the study authors state, the response is with one standard deviation until about 12 to 13 kHz

In full, this is the pertinent section of the paper

While it would be pedantic to make much of the difference marginally exceeding 1stdev in the 1-5khz band, it bears noting that the "shape" of the impedance curve is significant here, with the 60318-4 undershooting on Z in the ear gain band, and overshooting at low frequency. Just as with output impedance and load impedance in electrical signals, this has a different implication for the resulting eardrum FR than a flat difference in Z across the board.

Again, this is likely a pretty small effect, and in the places it's been potentially documented (e.g. Crinacle's comparisons of 60318-4 and Type 4620 IEM measurements), the impact on frequency response has been moderate, a few dB less bass in some cases. It's nothing that would make any reasonable or sane person discount 60318-4 measurements - but it is an example of why accurate loading can be significant.

What you have to also keep in mind that the above are under strict laboratory protocol. There is no way a reviewer is going to be able to assure compliance with their protocol. Indeed, even the authors of the study failed to do that for their full set of volunteers: "A total of 44 subjects entered into this study, but 12 were rejected because reliable measurements could not be obtained." That is nearly 30% exclusion!!!

Which, if the aim of reviewers was to measure wideband ear impedance, would be a real problem. However, while the input Z of the human ear does change with insertion depth for insert earphones (thus all this "propagation" business), that does not mean that it varies randomly, it's just about the modal resonances at high frequency shifting a bit. More accurate ear Z means a more accurate load, which, for cases where that matters, does mean somewhat more predictive measurements. It's the same as the argument for a 60318-4 coupler over a .4cc coupler, in fact, which long precedes demonstrable sound quality preference prediction differences between the two couplers.

So no way you want to run with the punchline like you are using. As I have repeatedly stated, the claim of accuracy here is a marketing one looking for verification.

Listen, if it would convince you that you are incorrect about the motivations involved here, I will go to the head of content tomorrow, on Independence Day, and say "Cory, I need to make a really boring video about headphone measurement systems. It's gonna get like 100 views, but it's gonna have the truth, and it's gonna mend a massive cleft of understanding and assumption of good faith, and that's worth it", and then I will write a script that specifically highlights why the 60318-4 is a pretty damn good system for measuring headphones, how the 5128 differs, and why those differences are ultimately rather small, record it, and post it. This isn't even a bet or something, you need do nothing, if that will legitimately reconcile this misunderstanding, I would be happy to do it.

 

[Mad_Economist]

Oh, absolutely.

I never ―or almost never― rely solely on the preset, whether it is from Oratory or generated with the AutoEQ tool on the Crinacle website (or the same frontend on Squig), I always use them as a starting point because I know that there is no absolute accuracy with the results of these measurements due to a multitude of variables (related to the measurement rig itself, the headphones and my own HRTF), then I make fine adjustements here and there using pink noise, sine sweeps and my own well-known music until I'm satisfied.

Then we're in concert there - I'm always a bit worried when people talk about measurements as a basis for EQ, because I've seen a lot of folks trying to nail jello to the wall with AutoEQ, but as a starting/jumping-off point I get ya completely.

My issue with the 5128/4620, aside from the limited number of available measured models, is that the proposed DF target does not serve me as a reference point in the same way that the Harman target does for IEC 60318, at least in the headphone models I've tested that have measurements available for both systems (with the Sennheiser IE300, which have measurements for both systems and are IEMs, I have had to spend much more time to achieve acceptable to "good" sound using the DF target with the B&K, so it's definitely not worth it for me, at least for now).

Right, so this one is an area where I think that there's been some bad messaging from us - in our defense, we expected to have a full-user-interactable measurement comparison tool ready by now, but hey, gotta plan for bad outcomes - and I want to make something a bit clearer: the target used on headphones.com derived from DF is not something that's being suggested as a most ideal response for headphones forever, or an overturning of the Harman work, or anything like that. It's literally a continuous slope applied to the DFHRTF, because the content team refused my initial pitch, which was only compensating to DF, and I didn't want to have any wonky little adjustments in there that would make it difficult for people to "undo" the preference adjustments. In the long term, my recommendation to Headphones.com has always been to use diffuse field alone for comparisons, with a "window" of the variations in preferred response that @Sean Olive has documented visible around the compensated trace - that remains the case.

Odds are that in the nearish future, we'll finally have our graph comparison tools operational, and people will be able to pick which of DF, DF with some preferential adjustments (probably user-set, as on @crinacle's site), and for 60318-4 measurements with GRAS pinnae Harman compensation they prefer. That has always been the endgame, although we've had a somewhat wiggly path to get there.

Ultimately, I've gotta take the blame here - I was really ardent that because of the sine illusion, we should move away from showing raw measurements of headphones and targets featuring HRTFs, because humans just plain objectively don't intuit the delta between said very well. The pushback I got was that compensating to DF alone would make people think that DF flat was the preferred response (which we have 25 years of data debunking), and compensating to Harman wouldn't work with the 5128 data. What some folks have done in that situation is trying to directly copy the Harman target over to the 5128, but given the differences of their pinnae, HRTFs, and acoustic Z this is not going to give people an accurate picture, and I'll die on that hill. Unfortunately, we couldn't get past the loggerheads between my refusal to use a more direct "copy" of Harman, and the content team not wanting to publish data with no preferential recommendations whatsoever.

The "split the baby" solution I proposed was that we just make the adjustment as simple as it possibly could be, minimizing the odds that we'd distort or mask some feature of the 5128, and making it as easy as possible for end users to remove that editorial adjustment both visually and if they chose to scrape the data. Some other options were floated - such as using the 1974 "Møller curve" from B&K, which Oratory does for his "optimum hifi" target - but ultimately we went with the simple slope under that logic. It was simply meant to represent the average tilt of the response which had been preferred in Olive, Welti, & McMullin 2013 vs. the flat in-room measurement, which is extremely close to the DFHRTF of the KEMAR. I've pushed back pretty hard against attempts to "fix up" the sloping so-called target since then specifically because I don't want people to think that this is some effort to propose a new way of doing things, and because I'd much rather push towards my original recommendation of normalizing straight-up DFHRTF compensation, which puts headphone frequency response in a psychoacoustically comparable space to in-room loudspeaker response (but without the annoyance of DI).

Hopefully in the very near future we'll have our data vis for content fixed up, and a lot of these concerns (and the combination of the slope with the DFHRTF in a single target) will be put to bed, and in the somewhat less near future we'll have some tools up on the site to let users play around with the kind of adjustments they'd prefer to make, similar to @crinacle. It's a work in progress, and the order of operations definitely got botched here, which is on me, but we are trying to make this stuff less opaque and more user friendly, even if it can look like the opposite sometimes.

 

[lazarian]

Hopefully in the very near future we'll have our data vis for content fixed up, and a lot of these concerns (and the combination of the slope with the DFHRTF in a single target) will be put to bed, and in the somewhat less near future we'll have some tools up on the site to let users play around with the kind of adjustments they'd prefer to make, similar to @crinacle. It's a work in progress, and the order of operations definitely got botched here, which is on me, but we are trying to make this stuff less opaque and more user friendly, even if it can look like the opposite sometimes.

Opposite is definitely correct... I'd suggest you're dealing with a very very limited minority of users who would understand things to the level of even being semi aware of what has existing studies behind it, what is based on other work, and what has listener preference work behind it.
I'd say if you went back over your post from the perspective of a layperson (ie. me) you'd start understanding why presenting users with simple easy to use controls with existing research backing it is key. Then you'd provide a secondary option, ie. B&K with DF / tilt and other aspects as a secondary source that is still being investigated.

 

[lazarian]

This does come back to what you're actually trying to achieve here at a fundamental level. If you're trying to ascertain what users prefer at a larger scale, and work through something you could use internally to create a product then you would go with a wildly different approach. In that case however you should still make it known what users are seeing, and present the options side by side with some information on all approaches used.