Poll: Should We Get Into Testing Headphones or Speakers?

[solderdude]

When using a HATS I would probably use Harman target in favor of both other corrections which are only suited for speakers. When using Harman target it is essential to use the same HATS.

Tyll visited there and compared his measurements to those of Harman. Tyll used the wrong correction from day one as he was ill advised by the guy that installed it. By the time he found out he already had so much measurements that he would have to do all his pdfs over again.
He even made some 'Harman corrected plots' which were better at representing tonal balance to how they are perceived but still 'off'.

Headroom uses Tyll's data and handled it better and gave the viewer options to choose correction or raw measurements which I think is the way to go.

Both Rtings and Sonarworks made their own curve. There is something to be said for this and Sonarworks his correction seems pertty good to me.
The plots of Rtings aren't far off either.
With Rtings the only debatable stuff is the way they rate/rank headphones. I have discussed this with them a few times (so have others) which resulted in different ratings for different applications.
Still, the website is called Rtings and primarily is about monitors and TV screens which are easy to rate objectively.
As they also were interested in headphones they started measuring them too and deliberately left out the listening part (not completely though, they do add some comments)
They insist they should rate based on numbers only and are still working on refining them and now and then re-measure stuff.
It is still a work in progress as it were.

I don't agree with the ratings based on how I think they sound. There is discrepancy between measured numbers and perceived SQ for sure.
There is discrepancy between how Tyll heard some headphones and how I do as well.

Harman correlates to sound, Rtings to numbers. There is a difference.
Sonarworks also correlates to sound (and uses measurements) but the amount and type of people that compare the sound is much smaller in numbers and use studio engineer types to determine what sounds closest to their monitors.
Harman uses averages of very large test populations.

I am curious to see what Amir comes up with and what he will measure and how it is displayed.
I really liked the 'sliders' from GE they were always pretty correct IMO.

(The above is from the HD650 which many hear know well)

 

[flipflop]

I think that you are underestimating how widespread variations in leak are, and how it can manifest

No, not at all. I just think it's important to stress the fact that leakage effects are the result of an improper fit between a headphone and its user. I don't discount how large the variations can be and I also recognize it's not a black-and-white issue.

the Sennheiser HD800 is almost universally agreed to be impeccably ergonomic, but I have verified leak-induced bass variations >6dB at 20hz (its large earpads in many cases have gaps in contact somewhere on the head) on human heads.

Good ergonomics doesn't necessarily mean good design. That said, even the Rtings subject wearing glasses doesn't provoke leakage effects that high on their HD 800 S. Overall, the design is fine, but not for everyone. An example of a bad design is AKG K545:

Almost all closed front volume designs display significant variation in the presence of leaks

Which is one of the reasons the open-back K712 was chosen for the study.

there are a number of uncertainties that can crop up between the HATS and the user that merit a bit of caution or some additional measures - which I don't think we disagree with, as we both seem to like RTings' positional variation measurement, for example.

I think the disagreement is in how much attention should be paid to those uncertainties. Leakage effects are, for the most part, uninteresting to me. The variations in the treble response, as a consequence of reseating headphones, seem more worthy of consideration.

 

[svart-hvitt]

Oh, I know your motivation. You have an irrational fear of anything associated with Harman as a company.


And what should be your starting point? Some random frequency response that doesn't have listener preference and then attempt to twist it into your HRTF?

Why don't you take a clock radio then and DSP it to make it sound the way you want for your stereo?

Irrational fear? Audio science seems to be unique in the sense that commercial companies do all the science. Consequently, we have Stuart/MQA write 3 out of 5 articles in AES’s special edition on high-resolution audio and one firm decide what is the correct curve. It’s as if Pfizer were to teach doctors correct medicine.

I labeled headphones a can of worms. My point is, in speakers we have the flat curve as a design target for a good theoretical reason. The flat curve is a reference, a benchmark that is supported by both theory and empirical tests.

The Harman curve isn’t supported by theory in the same sense as the flat speaker curve. Instead, it’s measurement without theory.

The preference polls of Harman can be likened to asking people about their preferred TV settings. Who knows if the Harman curve accidentally has a bias, like the bias of TV screens in the TV shop? The screens in the TV shops in all countries and parts of the world are way off the neutral target because that’s what customers «want», that’s what customers «prefer». Luckily, we have tools to determine what is a neutral TV and a neutral speaker. What is neutral in headphones?

As soon as you start to play with «the correct curve», which is based on measurements and not theory, you will start to experience that this curve will drift over time. When economists miss the target, again and again, they call it parameter drift. Same thing will happen in headphones due to «drift» and a lack of theoretical foundation and understanding of models.

Headphones have inherent challenges. What could be done, however, is encourage headphones producers to make headphones that have headroom enough to undergo EQ, so that one can apply the curve one wants as well as one own’s unique HRTF data. All done in software. To print a certain «correct» curve into headphones hardware make them ripe for obsolescence as a new and «correcter» curve is launched. Samsung is well known for abandoning customers with for example TVs where the software is obsolete when a new model is launched. So it’s not irrational to fear that Samsung will make other hardware too, that is obsolete by design due to software changes, or curve corrections. Samsung’s strategy is not sustainable, but it’s profitable.

 

[solderdude]

seal breach K7XX (= K712 with an added foam ring)

Below seal breakage on a closed (but ported) headphone: (beyerdynamic Custom One Pro)

Below seal breakage on HD820S

Below seal breakage on HD58X:

Below the odd one out. The only closed headphone I measured that sounds and measures the same with and without seal breakage... The Final D8000
Red = perfect seal, purple - seal broken with 6.3mm TRS plug between the pads and test rig.

 

[Krunok]

Headphone guys, no matter how hard you try to hijack this thread you are still loosing at the poll, by a big margin..

 

[solderdude]

Nope because Amir wants to measure headphones ....

 

[Krunok]

Nope because Amir wants to measure headphones ....

He doesn't need a poll to do what he wants - poll is about what people want!

 

[ExEnemy]

Why not both?
headphones pool is quite shallow compared to speakers and not like people want to see measurements of every one of them, just the juicy stuff like Beats, airpod, Grado, Focal ect )))
Honestly i knew about this forum from Reddit and my own disillusion with Schiit and that Best Audio Gang Forum(complete Schiit-show). I always see ASR as science vs nonsense or a snake-oil busting forum and that's i'd like to see: Cables, power conditioner, Chi-fi stuffs, overhyped shits got owned

 

[jazzendapus]

The Harman curve isn’t supported by theory in the same sense as the flat speaker curve. Instead, it’s measurement without theory.

That's not quite true. Harman's headphone curve follows the same logic as ideal speakers curve. The theory is that in order to achieve perceived accuracy with headphones, the headphones should sound (at least tonality wise) like accurate loudspeakers in a room. Their headphone curve is what you get by measuring accurate speakers at eardrum level + some modification in the bass range.
More on that here: https://www.innerfidelity.com/content/acoustic-basis-harman-listener-target-curve

 

[192kbps]

Got me curious: Which one was this? If it's open to the public to know? If not, I'd love to hear it on pm

SONY-7506

 

[oivavoi]

SONY-7506

I'll be damned... I just realized I have those! But some while ago I stowed them away, because I consistently preferred listening to my Sennheiser 650s. Possibly because the 650s and the Sonys are closed.

 

[oivavoi]

Nope because Amir wants to measure headphones ....

Just a follow-up question, Solderdude: Is the EQ of the Kameleon amp/board based on the Harman curve?

 

[svart-hvitt]

That's not quite true. Harman's headphone curve follows the same logic as ideal speakers curve. The theory is that in order to achieve perceived accuracy with headphones, the headphones should sound (at least tonality wise) like accurate loudspeakers in a room. Their headphone curve is what you get by measuring accurate speakers at eardrum level + some modification in the bass range.
More on that here: https://www.innerfidelity.com/content/acoustic-basis-harman-listener-target-curve

Things are a bit more complicated. The curve means you manipulate, alter, change the source. «Flat curve speaker» means no such manipulation of source.

Human hearing has evolved our HRTF. If you take away the individual’s HRTF and replace it with an alternative, it boils down to how representative that alternative is of parts of the individual’s hearing mechanism, say HRTF.

Mind you, I was ridiculed in another thread by experienced ASR members for questioning the HRTF concept, i.e. every individual’s hearing mechanism is individual (they believed every individual’s HRTF must be measured). In this thread, I have been ridiculed for asking why Harman took the individual’s HRTF out of the equation. How can it be, if we’re talking science here, that you get ridiculed for taking one position in one thread, while being ridiculed for taking the opposite position in another thread? This is a stupid question I feel is unanswered.

I am here to have fun and ask stupid questions. However, does the behaviour of ASR members make sense? Can all be right?

Or is it wiser to take a middle way, middle position, before headphones have been scrutinized by more researchers, more teams, by more interests, before putting all the eggs in the Samsung/Harman basket?

 

[svart-hvitt]

Just a follow-up question, Solderdude: Is the EQ of the Kameleon amp/board based on the Harman curve?

«The Harman curve», you wrote. Which of them? There have been more than one Harman curve. My forecast is there will be more.

You’re a researcher and scientist. How do you normally respond to references that are drifting? And this is not social sciences where drift is inherent. This is primarily the «harder» sciences. Humans don’t evolve from year to year, as the Harman curve does.

 

[wiggum]

That’s my whole point: Harman has skipped the whole HRTF issue to promote one curve to rule them all. I wonder, is it consensus in audio science that measuring individuals’ ears (HRTF) is unnecessary?

I see where you are coming from, but you are ignoring some facts.

From what I have learnt, HRTF is significant for IEMs/supra-aural not for circumaural headphones because they don't bypass the pinna and the auditory canals as IEMs do. Apart from obvious differences in ear size and shape that everyone can observe, there are gender and race differences in ear canal length and diameter that affects the position of peak resonance(2.5 -3.5kHz). Both of them contribute towards HRTF. As long as you don't bypass them, your HRTF is being applied. There are other factors like size of head that affect HRTF, but I don't think they are as significant as the pinna and the earcanal.

 

[solderdude]

Just a follow-up question, Solderdude: Is the EQ of the Kameleon amp/board based on the Harman curve?

On my 'own' correction curve which has bass boost but less than Harman (I think it is too much) and not as unnaturally steep.
Below my compensation curve

A headphone that measures flat sounds a bit 'thin' at lower listening levels.
I prefer to listen at lower listening levels.

 

[svart-hvitt]

On my 'own' correction curve which has bass boost but less than Harman (I think it is too much) and not as unnaturally steep.
Below my compensation curve

A headphone that measures flat sounds a bit 'thin' at lower listening levels.
I prefer to listen at lower listening levels.

I guess you low SPL remark is speaker relevant as well?

 

[solderdude]

I'll be damned... I just realized I have those! But some while ago I stowed them away, because I consistently preferred listening to my Sennheiser 650s. Possibly because the 650s and the Sonys are closed.

Well the Sony has a +10dB peak at 10kHz which makes them 'laser like' but not that 'hifi'

 

[solderdude]

I guess you low SPL remark is speaker relevant as well?

yes, in principle.. but in an not treated room one usually gets some extra bass boost anyway which kind of fills it in already.

 

[solderdude]

Mind you, I was ridiculed in another thread by experienced ASR members for questioning the HRTF concept, i.e. every individual’s hearing mechanism is individual (they believed every individual’s HRTF must be measured). In this thread, I have been ridiculed for asking why Harman took the individual’s HRTF out of the equation. How can it be, if we’re talking science here, that you get ridiculed for taking one position in one thread, while being ridiculed for taking the opposite position in another thread? This is a stupid question I feel is unanswered.

It depends on which harman curve we are talking about. There are several as you said. Older ones, newer (revised) ones, for speaker and for headphones differ as well. I think just like the Rtings plots it is a work in progress.
Then there is the well known 'Harman curve' for raw signals (which is what Amir meant) which incorporates the bass correction and slight treble slope + the HRTF correction for headphones (which differs from speaker HRTF corrections)

Usually with "Harman' curve one means a certain bass boost and treble slope. Those curves are well known.
I put a few in one plot. (see below) with one of the early OW corrections. I believe the newer one is closer to the GE curve in the lows.

The Harman curve is more effective in the lows and 'steeper'