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Hifiman Sundara Review (headphone)

solderdude

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Ah.. yes .. I get what you mean ...you are correct.
You basically are looking at errors in the measurement chain. They are measurement rig dependent so different rigs will have different peaks and dips. Even on a really flat headphone. On top of that the dips and peaks also differ when the distance, angle and driver size of a perfect driver differs.

headphone measurements are not exact. It is handy to know the limitations of each HATS and take measurements with a grain of salt. Especially mine are rather limited from 1kHz to 5kHz depending on angle of the driver where the measurements from Amir and Oratory are vey trustworthy there. One can use that info when evaluating measurements.

Below 200Hz seal issues can create substantial errors, above 6kHz placement and the headphone itself (interaction with the test fixture) can completely skew resulting plots (as well as the used correction and target).

So it is approximate and can tell something about the headphone.
 

RHO

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Are you telling me it is a natural phenomena because of the way the ear is constructed?
If the latter, then the brain has learnt (over few thousend years) to compensate for that, and it should no longer be shown or at least included in the Harman curve!
The "concha simulator" has ignored the brain/ear combined effect.
That is how I understand it.
Nothing wrong with it showing up in the measurements. It's the same as the ear-gain thing but in reverse.
I don't think Harman is relevant above 8kHz. (or was it 10Khz?)
The rigs with pinna never take the brain into account. That's why we don't want to see a flat FR when looking at measurements on those rigs.
 

Ken Tajalli

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Ah.. yes .. I get what you mean ...you are correct.
You basically are looking at errors in the measurement chain. They are measurement rig dependent so different rigs will have different peaks and dips. Even on a really flat headphone. On top of that the dips and peaks also differ when the distance, angle and driver size of a perfect driver differs.

headphone measurements are not exact. It is handy to know the limitations of each HATS and take measurements with a grain of salt. Especially mine are rather limited from 1kHz to 5kHz depending on angle of the driver where the measurements from Amir and Oratory are vey trustworthy there. One can use that info when evaluating measurements.

Below 200Hz seal issues can create substantial errors, above 6kHz placement and the headphone itself (interaction with the test fixture) can completely skew resulting plots (as well as the used correction and target).

So it is approximate and can tell something about the headphone.
Again check to all.
Indeed Amir has a disclaimer at the beginning of every test of a headphone in bold letters, still some ignore that.
I was having a discussion at HE560 review page with a couple of members, it got heated when I claimed that I listen to headphones and ignore the graphs - They implied the data from graphs is irrefutable, and takes precedence over what I hear!
 

RHO

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Basically if a perfect transducer should exist, with a ruler flat FR, then showing a "graph of the transducer" should be a flat line, and any irregularity of the ear canal, microphone response curver etc. should not be included.
It would be ruler flat in what situation?
You would need to have perfect copy of your own outer and inner ear on the rig. You would need to know how your brain compensates for deviations from a perfectly flat FR response (which changes over time when using different audio gear with different FR -> brain burn-in).
And then it would only measure flat for your ears in exactly the same position it was in on the measurement rig.
That makes no sense.
 

RHO

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They implied the data from graphs is irrefutable, and takes precedence over what I hear!
They are not irrefutable, but take precedence over what you hear.
A computer has no brain burn-in for instance. It does not suffer from different moods or changes in health ... It shows repeatable data that you can learn to read. And imperfections can be taken into account when reading the data.
 

Ken Tajalli

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They are not irrefutable, but take precedence over what you hear.
A computer has no brain burn-in for instance. It does not suffer from different moods or changes in health ... It shows repeatable data that you can learn to read. And imperfections can be taken into account when reading the data.
We are all good here.
I judge my headphones by what I hear - you can judge them by computers and graphs which can incidentally be wrong!
If a pair of headphones you listen to has plenty of deep bass, but Oratory curve says it is drooping by 8dB, I should ignore my ears and boost my bass by 8dB and keep convincing myself "Now this is correct!" .
Because that is exactly what a lot of people are doing!
Repeated test gear imperfections should be compensated for, and not thrown at people as information.
After all that is the difference between Data and Information, Data is raw, information is deducted from it.
After all that is what we are trying to do, judging headphones, not imperfections of test gear or how nice raw data looks on a coloured graph, or did I get that wrong too?
 
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Jimbob54

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We are all good here.
I judge my headphones by what I hear - you can judge them by computers and graphs which can incidentally be wrong!
If a pair of headphones you listen to has plenty of deep bass, but Oratory curve says it is drooping by 8dB, I should ignore my ears and boost my bass by 8dB and keep convincing myself "Now this is correct!" .
Because that is exactly what a lot of people are doing!
Repeated test gear imperfections should be compensated for, and not thrown at people as information.
After all that is what we are trying to do, judging headphones, or did I get that wrong too?
The problem is, given the exact same pair of headphones, you hear enough sub bass (for you), I hear too much (for me) and someone else hears not enough (for them). The measurement rigs (upon which you can equalise to Harman target) just give a common reference point.
 

RHO

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We are all good here.
I judge my headphones by what I hear - you can judge them by computers and graphs which can incidentally be wrong!
If a pair of headphones you listen to has plenty of deep bass, but Oratory curve says it is drooping by 8dB, I should ignore my ears and boost my bass by 8dB and keep convincing myself "Now this is correct!" .
Because that is exactly what a lot of people are doing!
Repeated test gear imperfections should be compensated for, and not thrown at people as data.
After all that is what we are trying to do, judging headphones, or did I get that wrong too?
I don't judge my headphones by measurements only. No-one does that!
But you can differentiate a good headphone from a bad one by looking at the measurements and you can judge if a model will likely appeal to you by looking at the measurements, without having to buy the thing first.
And even if the measurements aren't perfect, they are much more perfect then some telling their subjective experiences. Because those experiences tell you nearly nothing about how YOU will experience them. YOU may not like "neutral". YOU can have a severe hearing deficiency at a certain frequency. I can have one in a completely different frequency range. That will severely influence how we experience sound.
Measurements are a much more reliable reference, because they exclude the human experience completely.
EQ recommendations are made to get to a reference. Whether you like that reference or not is 100% up to you. If you don't than change the EQ and enjoy the headphones to your hearts content. But they will not be "neutral" (referenced to the target). If I like neutral, I will not like your EQ at all. And if I don;t like neutral, I may like something completely different than you.
 
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Ken Tajalli

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I don't judge my headphones by measurements only. No-one does that!
You'd be surprised!
But you can differentiate a good headphone from a bad one by looking at the measurements and you can judge if a model will likely appeal to you by looking at the measurements, without having to buy the thing first.
Well I can relate to that.
And even if the measurements aren't perfect, they are much more perfect then some telling their subjective experiences. Because those experiences tell you nearly nothing about how YOU will experience them. YOU may not like "neutral". YOU can have a severe hearing deficiency at a certain frequency. I can have one in a completely different frequency range. That will severely influence how we experience sound.
Correct, but majority of members I have had interaction with on ASR (in particular) are number-junkees. If one looks at data provided as an indication and not last word, then we have no issues.
Measurements are a much more reliable reference, because they exclude the human experience completely.
EQ recommendations are made to get to a reference. Whether you like that or not is 100% up to you. If you don't than change the EQ and enjoy the headphones to your hearts content. But they will not be "neutral" (referenced to the target). If I like neutral, I will not like your EQ at all. And if I don;t like neutral, I may like something completely different than you.
How many times have you met members on these very pages, that even before they recieve their gear, they have already programmed in the Oratory or Amir's EQ settings? be honest!

Those knowledgable enough to read and comprehend the graphs and data presented are in the minority, I believe Oratory and the like have a duty to include in huge letter disclaimers on every graph (similar to Amir) to say that these graphs are approximate, and try to filter out, what is test gear related.
It doesn't take a genious to collect a 100 curves from Oratory's database, and come up with computer function to filter the test gear out.
 
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RHO

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How many times have you met members on these very pages, that even before they recieve their gear, they have already programmed in the Oratory or Amir's EQ settings? be honest!
I am surprised every single time I read it, but it hasn't happened that often. So, I guess a few do it, but not many. My experience, which is completely subjective. I haven't done a statistical analysis on the numbers yet. ;)
But if you want to implement EQ those setting are a good way to start.
 

solderdude

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It doesn't take a genious to collect a 100 curves from Oratory's database, and come up with computer function to filter the test gear out.

Alas not that simple. You would still need to know what the actual depth of the 10kHz dip (and at other frequencies) are and then that would be an average which won't necessarily lead to a correct correction. The problem is lack of reference.
 

Ken Tajalli

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Alas not that simple. You would still need to know what the actual depth of the 10kHz dip (and at other frequencies) are and then that would be an average which won't necessarily lead to a correct correction. The problem is lack of reference.
Then the huge-letter disclaimer to educate & inform - at least!
 

dennis h

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Indeed this is proof the HATS used clearly doesn't measure correctly at 10kHz which is a known fact.
Look at ALL plots made by Amir and Oratory you will see that this is in the measurement rig.

Look here... different measurement rig... surprise no 10kHz dip.
Then look at consistency and notice how some people have dips and others show peaks above 10kHz.
Its the reason why most plots are greyed out above 8kHz to 10kHz.
This is the reason why some people are bothered by it and you (lucky card) cannot hear it.
thanks
this beginner can relate to those graphs
what measuring rig ?
 

Chester

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Looking at the graphs for the Sundara and the HE400 SE, there doesn’t seem to be much between them from a performance perspective.

I appreciate most people are unlikely to have spent lots of time listening to both of these. However, I will ask my question nonetheless. If one already owned the HE400SE, other than what looks like better build quality, are there any sonic benefits (with or without EQ) the Sundara offers?

Thanks
 

solderdude

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Sundara is kind of a side grade with better build quality. Whether or not you may appreciate small tonal differences no one can tell.
Someones 'huge' differences are anothers 'can't really tell a worthwhile difference'.
 

Chester

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Well, given quite a few people seem to be wondering about the differences between these two models, I just purchased a pair so I can do some side by side comparisons. It won’t be particularly objective or scientific but I will share my thoughts when they arrive and I’ve had time to compare.
 

Ezees

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I’ve observed something a little curious about my copy of the Sundara and your input would be welcome.

I bought a pair from an official retailer (Son-Video.fr) which had been out of stock for a while and only recently received a new shipment. On the box there is a stamped date mentioning April 2021 - the shipping date out of China ? The pads are of the bulging seams kind, so I’m going to assume that it’s the “revised” version.

Something that I’ve started to become quite a bit wary of in regards to FR curves are sharp, high-Q asymmetrically sloped features of that kind (which you’ll quite frequently see with quite a few planars BTW) :

View attachment 132771

Not that it looks bad per se - at such a low magnitude I probably wouldn’t be able to hear it… if indeed it turned out to measure like this on my own head.

Thing is, when I started listening to my pair I noticed that something wasn’t quite right. Running sweeps I could indeed easily notice that sharp peak then dip around 1kHz or so. Since I felt that I wouldn’t be able to hear it to such an extent if it was as moderate as it measures on this site - or on some others - I went for the next step.

I’ve started to use in-concha microphones to measure headphones’ FR below 1kHz or so. More here : https://www.head-fi.org/threads/the...-at-a-breakthrough-value.943107/post-16300055
With some larger over-ears I find the data in the 1kHz-3kHz or so range obviously inaccurate but still somewhat exploitable with care in relative terms between headphones.

This is how my pair of HD560S (Left and right channels, top traces), HD650 (Left and Right channels, middle traces) and this pair of Sundara (left and right channels, bottom traces) measure :
View attachment 132766

Don’t look too hard at the small recurring channel imbalances / tilt, if you look at the scale it’s within fairly narrow values (0.5-1dB) for the most part and a byproduct of pads compression / seal, placement variation, left and right microphones calibration - there’s one for each ear, etc. These traces are individual measurements but they’re representative of an average of five measurements where both the microphones and the headphones were re-positioned (I can provide the five individual traces for each headphones and the average, they basically overlap each others for the most part, with these specific headphones in that frequency range I get decent repeatability with these microphones even from day to day if you consider 0.5-1dB decent repeatability).

The results seem to be that this pair produces on my head a very sharp dip between 1-2kHz on both channels, with a sharper slope on the right channel in orange (and I can’t help but notice another interesting dip higher up, at around 2500Hz on the same channel, that seems to be a multiplier of the first, while the left channel remains better behaved - a coïncidence or something more interesting ?).
It doesn't look quite like the older revision that was depressed in the 1000-3000Hz range, the drop is a lot sharper and more similar to what the newer units seem to produce in some measurements, albeit with a larger magnitude.

As a side note you’ll also see that the bass response isn’t that much stronger in the sub-bass than with some other open over-ears - not necessarily a surprise, some (but not all) other websites measuring the more recent version also got similar results (Rtings, among others). Sean Olive’s copy which measurements were shown here showed something similar. The way the bass response is shaped between the left and right channels on the Sundara suggest to me that there is a slightly different seal quality between the channels.

Since this is in the range where in-concha microphones start to be increasingly less reliable, just to make sure I fired up my prototype probe / tube microphones (based on a David Griesinger idea). More details about it here : https://www.head-fi.org/threads/the...-at-a-breakthrough-value.943107/post-16339008

It’s a work in progress so read even less into it than with the in-concha mics (calibration is an issue, but the most egregious peaks should have been effectively neutered), and besides I didn’t shove it quite as far as I should for accurate measurements above a few kHz as it was a quick job and I didn’t want to fiddle with it too much. But at least up to 3-4kHz the values should be at least a decent representation (with this sort of microphone, the values change with insertion depth, but there is a point beyond which they’re stable and stop changing - the higher the frequency, the deeper the insertion needs to be to reach stability. With these measurements that’s the case at least up to 3kHz for sure, I’ve designed the probe to be slidable without moving the headphones and progressively insert the probe while making regular measurements to make sure). The probe wasn’t moved between the measurements of the three different headphones.

Here it is, for the right channel only (HD560S in green, HD650 in blue, Sundara in red) :

View attachment 132769

So with a completely different microphone approach we can see the same dips at around 1250 and 2500Hz on the right channel.

I’ve tried to change position of the Sundara, apply a bit more pressure on the pads, etc. to not much avail in regards to the 1-2kHz problems even if it did change slightly the bass response (emphasis on slightly, I have a feeling that the air gap is happening somewhere else than between the pads and my skin anyway - perhaps the fact that only the inside edge of the pads seals against my head and air passes through the perforated platter on the inside and the vented fabric facing my head, the latter of which is not being pressed against my skin near the outside edge under normal use and even when pressing the pads a bit).

What I’m wondering now is :
  • Since both channels exhibit a fairly sharp and strong peak then drop, if it is a question of sample variation, at least the driver pairing process and the resulting manufacturing ensure decent channel balance. Does Hifiman practice driver pairing at the factory (for example the way Sennheiser seems to do, even at a fairly cheap price point, for their passive audiophile headphones) ? Or would it be a case of low variation within batches and higher variation inter batches ?
  • If it isn’t a question of sample variation, could it be the result of the interaction between the headphones and my own individual anatomy ? Any pointers as to what mechanism would be at play in that case in that 1-2kHz range ?
Planar magnetics can often mess with a microphone's operation - the magnetic part of planar magnetics can potentially affect the coils in a microphone, which have their own magnetic fields. May be why you see such a raggedy FR plot for the Sundaras. Maybe.
 

solderdude

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the magnetic part of planar magnetics can potentially affect the coils in a microphone

Almost all microphones used in headsets and N.C. are electret. They are not bothered by a static magnetic field.

The 'wiggles' are seen in almost all hifiman headphones and can differ in L & R drivers.
 
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