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Hifiman HE400i Review (planar headphone)

Cahudson42

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Does the HE5XX differ much in driver technology to the HE4XX (HE400i)? If it has a different driver technology then that might be interesting,
Yes. It does. The HE4XX has a single side of magnets, on the outside of the diaphragm.. The HE5XX has double -sided magnets, on each side - inside and out - of the diaphragm. The audible result - has been debated ad nauseum.

The double -sided do appear to be the approach HFM started with , with the HE6 etc

Here is the HFM 'evolution tree':
https://hifiman.com/evo-fhp/tree.html#id_0

The right branch, double sided. The middle, double but asymmetric. The left, single-sided.

Note the $6000 Susvara is part of the double-sided. As is the Ananda, and Arya.

Well worth digging into the differences.
 
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amirm

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The older one (with SMC connector) most likely has backplates, newer one not - I haven't seen any reports of one with an SMC connector and no backplate. The distortion measurements posted above were from that older one. The frequency response from that matches better with the unit measured for this review, suggesting the latter also has backplates. The newer unit measured in 2017 has less distortion than the older one (and less distortion pretty much across the board than the HD800S measured on exactly the same rig, as posted previously).

Newer HE400i from 2017 (no backplate):

dist-he400i-l.png


So yeah, no distortion issues there.
Please stop posting random conjecture like this. I purchased mine in November 2017. By then the pack plate was removed. Here is a shot of mine:

HE400i no back plate.jpg


This is what it looks like on the inside: https://www.head-fi.org/threads/new...n-or-just-a-mixup-with-he400s-drivers.791185/

1520332


In contrast, the so called "back plate" looks like this from the same thread:

1521504


Mine also has the 2.5mm connectors, not SMC. As far as I can tell, the only version newer than mine is the 2020 which has completely different headband and such which can't be confused with my version.

As for HE4XX, it too lacks the back plate and seems quite similar to mine:

f46515ad-45b7-4473-a6f8-b1bad33b32b6.__CR0,0,970,600_PT0_SX970_V1___.jpg


I also want to caution you against copy and pasting other people's measurements without attribution. Not only is that the proper thing to do, it is also important to let us see what the test conditions were.

Bottom line, your conclusions so far regarding distortion are incorrect. There is mid-frequency distortion that doesn't exist in other headphones and all else being equal, this distortion is more important than what is in bass area.
 
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amirm

amirm

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Most distortion measurement plots and posts are aimed at 2nd and 3rd harmonics. There are a number of AES papers that document that 2nd and 3rd harmonics are largely benign or are masked by the program material.

I am of the opinion that higher harmonics are much more problematic, additionally higher harmonics are not masked by the program material.

If we are focused on 2nd and 3rd harmonics we may be focused on innocent bystanders and not the real offenders.
Yeh, I don't know why some AP measurements limit the harmonics to just two. There are other measurements that show them so I could try to format those and print them instead. For now, we can infer the level of the higher order harmonics from what I have posted:

index.php


Notice that THD (in red) has all the harmonics included and how the second order, in green, hugs the THD curve well. What it doesn't include seems to be covered by third harmonic leaving little room for higher order harmonics. The exception seems to be in bass so I will see if I can get the make up of that and post.
 

F1308

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Ok, I honestly feel super confused reading statements like this. Can you tell me how you factor in the way the recording is mixed and the fact that it already comes to you 'EQed' by the studio engineer?

I tried 'correcting' towards the Harman target and while it was nice on some records, I found many others plain unlistenable. In most of those cases my impression was that I had boosted the frequencies already emphasized in the source material itself.

I listen the most during work, and sometimes I go through 10-20 different releases. I just can't imagine tweaking the EQ for each record...
I assume that @amirm is using beatifully produced reference recordings, but my mood swings can take me from a jazz album to a noisy black metal one, then to some 80s synthwave and so on:) I just can't imagine how this would work in real life, unless you limit yourself to consuming only 'audiophile-grade' recordings.


Am I missing some basic point here or is it right to say that EQing towards any target curve without analyzing the actual input does not make much sense? Shouldn't 'The Holy Grail of Equalization' be something closer to an auto-tune processor?
I don't know...
It is said an EQ is applied (such as 1516/3dB/Q3 to a loudspeaker) and the thing turns to sound outstanding.
https://www.audiosciencereview.com/...dio-monitor.18505/#lg=attachment99914&slide=0
That is it. A believer...? No...? Yes...?
 
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the_brunx

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I wonder why the big professional companies like Sennheiser, AKG, Sony, Shure, beyerdynamic etc. never touched planar magnetics, although have sometimes done other types of transducers, is there a reason for this?. I know from online stories of audezes and hifimans that they are very prone to go defective. is this a planar magnetic thing or just badly implemented?
 

wasnotwasnotwas

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I wonder why the big professional companies like Sennheiser, AKG, Sony, Shure, beyerdynamic etc. never touched planar magnetics, although have sometimes done other types of transducers, is there a reason for this?. I know from online stories of audezes and hifimans that they are very prone to go defective. is this a planar magnetic thing or just badly implemented?

Pick up a pair of planar , wear them for 20 minutes then tell me you'd like to wear them on/off/on/off for a 10-30 hour day. Compared to a pair of these https://www.amazon.co.uk/AKG-Profes...dphones&qid=1608425202&sr=8-6&tag=googhydr-21
 

Robbo99999

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I think we need to take care here. "probably wouldnt sound good without EQ" really needs a qualification- "probably wouldnt sound good without EQ to someone who's preference is [insert target curve of choice]" .

I guarantee they sound absolutely heaven sent to someone who listens to music through some dogs**t supermarket own brand poorly sealed earbuds.

I place no value on user reviews on sites- but to illustrate my point, I bet a goodly proportion of these folks aren't lying. Whether they have the widest and deepest experience in head-fi is a different story. https://drop.com/buy/drop-hifiman-he5xx/reviews#reviews

Point being, as with electronics that introduce audible (euphonic) distortion, we need to separate "sounding good" from objectively "good".
Well, in terms of the "random frequency responses" of headphones that aren't based around either Harman or Diffuse Field then it's a matter of blind luck if your own HRTF happens to match that of said "random frequency response", therefore it's probably safe to say that for most people if there are big deviations from the Headphone Harman Curve that it won't sound right. Sure they're bound to sound better than some super ****** really cheap headphones, but that's not our benchmark is it. In my opinion, if the Headphone Harman Curve doesn't sound right to you then it's a major uphill battle to find good sound from headphones....if I wasn't a Headphone Harman Curve "positive responder" then I'd probably create my own Target Curve by using trial & error around tweaks on the existing Headphone Harman Curve (& comparing that to "flat reference speakers" on my favourite tracks as a means of sanity checking EQ changes), rather than randomly trying headphones that have random frequency responses....would be impossible to find a match for accurate sound that way. So I think it's safe & legitimate to make some generalisations to how a headphone would sound based on it's frequency response.
 
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Robbo99999

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Please stop posting random conjecture like this. I purchased mine in November 2017. By then the pack plate was removed. Here is a shot of mine:

View attachment 100347

This is what it looks like on the inside: https://www.head-fi.org/threads/new...n-or-just-a-mixup-with-he400s-drivers.791185/

1520332


In contrast, the so called "back plate" looks like this from the same thread:

1521504


Mine also has the 2.5mm connectors, not SMC. As far as I can tell, the only version newer than mine is the 2020 which has completely different headband and such which can't be confused with my version.

As for HE4XX, it too lacks the back plate and seems quite similar to mine:

f46515ad-45b7-4473-a6f8-b1bad33b32b6.__CR0,0,970,600_PT0_SX970_V1___.jpg


I also want to caution you against copy and pasting other people's measurements without attribution. Not only is that the proper thing to do, it is also important to let us see what the test conditions were.

Bottom line, your conclusions so far regarding distortion are incorrect. There is mid-frequency distortion that doesn't exist in other headphones and all else being equal, this distortion is more important than what is in bass area.
Ah, fair do's then on the lack of bass plate on your HE400i measured headphone. (So that version wouldn't measure any better than the one you measured, because that is the one you measured!)
 
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amirm

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@amirm, could you export the error curve for the HE400i and/or HD800S, just so that I can make sure my interpolated curve isn’t causing issues?
Sure.


BTW, personally I would zero out all response errors above 10 kHz or even a bit lower as I am not trying to optimize anything there and the fixture has no assurance of correctness there. Furthermore, no one but Harman has the proper pinna used in the research (the one that Todd built) and the coupler is the older one as well (with higher peaking in treble). So while it would be good to compute the number, we are not going to get precision.
 

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amirm

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In the end, I won’t buy anything which doesn’t have tone controls or the possibility of tailoring the sound of my music the way I like it. It is a deeply personal experience after all, no?
It is worse than that in that there are no standards in audio production. That is, we don't know the frequency response of the monitors used to produce/master the music. So some amount of tone control is necessary. Indeed many times I get the EQ done and it sounds good on a number of tracks then all of a sudden it sounds a bit bright. Or bass is a bit much. We need real-time tone controls or better yet, per track/album equalization in our players.
 

MZKM

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Sure.


BTW, personally I would zero out all response errors above 10 kHz or even a bit lower as I am not trying to optimize anything there and the fixture has no assurance of correctness there. Furthermore, no one but Harman has the proper pinna used in the research (the one that Todd built) and the coupler is the older one as well (with higher peaking in treble). So while it would be good to compute the number, we are not going to get precision.
Ok, I actually get a score of 81 from that (compared to the 77 I got); so I’ll have to investigate that.

EDIT: That is at like 1/2 the resolution, so the smoothing is likely helping the score. Also, this looks like the deviation of just the left channel, not the average.
 
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F1308

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It is worse than that in that there are no standards in audio production. That is, we don't know the frequency response of the monitors used to product/master the music. So some amount of tone control is necessary. Indeed many times I get the EQ done and it sounds good on a number of tracks then all of a sudden it sounds a bit bright. Or bass is a bit much. We need real-time tone controls or better yet, per track/album equalization in our players.

How funny is the fact I can remember sellers recommending that maker for pop music, that other one for classical....
I guess you could match a loudspeaker maker for every singer singing...
Definitive Technology...? Vangelis.
JBL? Julio Iglesias.
HEDD ? XII-XVII centuries.
HEDD+subwoofer/s? Anyone !!!! But wait for MK2.
 
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wasnotwasnotwas

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Well, in terms of the "random frequency responses" of headphones that aren't based around either Harman or Diffuse Field then it's a matter of blind luck if your own HRTF happens to match that of said "random frequency response", therefore it's probably safe to say that for most people if there are big deviations from the Headphone Harman Curve that it won't sound right. Sure they're bound to sound better than some super ****** really cheap headphones, but that's not our benchmark is it. In my opinion, if the Headphone Harman Curve doesn't sound right to you then it's a major uphill battle to find good sound from headphones....if I wasn't a Headphone Harman Curve "positive responder" then I'd probably create my own Target Curve by using trial & error around tweaks on the existing Headphone Harman Curve, rather than randomly trying headphones that have random frequency responses....would be impossible to find a match for accurate sound that way. So I think it's safe & legitimate to make some generalisations to how a headphone would sound based on it's frequency response.

I think you just kind of proved my point. Several times over. I never once mentioned a specific target curve, yet you say.. "if there are big deviations from the Headphone Harman Curve that it won't sound right". There are many posters on here who dont think the Harman curve sounds "right" So, as a "positive responder" I think you mean "right to me"?

"but that's not our benchmark is it" - "our" being who? Also, which headphones hit "our" benchmark as stock? Please, limit to your personal experience.

"rather than randomly trying headphones that have random frequency responses"- who suggested this ? You said , quite clearly , "HE5XX looks like quite a messed up frequency response at stock though, so probably wouldn't sound good without EQ." I am cautioning you from making such pronouncements. I would limit to "HE5XX looks like quite a messed up frequency response at stock though". You surely understand the difference between objective assessment and subjective preferences. Ever listened to a pair of headphones that have the same FR as the 5xx? If yes, then you have a valid point, for you and you only.
 
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amirm

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EDIT: That is at like 1/2 the resolution, so the smoothing is likely helping the score. Also, this looks like the deviation of just the left channel, not the average.
I did indeed smooth that to 1/12 octave I think to make it easier to figure out what to EQ and what to not. I don't do any averaging of the two channels. I am not happy with averaging as a filtering tool. If you average two channels, it is not representative of either! There is a primary channel I use to calibrate so that is what I use there.
 
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amirm

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You surely understand the difference between objective assessment and subjective preferences. Ever listened to a pair of headphones that have the same FR as the 5xx? If yes, then you have a valid point, for you and you only.
You are going fair bit far with that statement. :) The preference curve was determined in controlled listening tests, not a computation or modelling. So it is what people heard. There is a degree of accuracy of course and the curve is heavily filtered but still, the heart of it is listening tests. If we all use the same then there is hope that one day we all experience music the same way and as intended.
 

nj75f

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The distortion in the midrange roughly correlates to the lower level from ~1kHz to 3kHz. I've seen similar correlations at various frequencies in a lot of headphone measurements, it makes me think it's designed in by the manufacturers to keep distortion under control at the cost of more idealized FR. People then go on to EQ the headphone to correct the FR, but just give subjective impressions and don't seem to measure the distortion. This leaves open the huge question of how much distortion there is post-EQ in these frequency ranges since it's starting from a higher distortion baseline.

Is it so hard to do the measurement suite again after EQ? Otherwise these headphone tests seem like a waste of time, there are plenty of people doing the same measurements. It's just not very ASR-like to do a bunch of measurements, make some big changes via EQ or whatever, then draw conclusions with EQ only from subjective impressions.

One of the many things I'd like to see in real audiosciencereview.
But as already mentioned here, he stubbornly clings to being (for the time being) one of the subjectivist reviewers himself, since he writes subjectivist headphone reviews mixed with a tiny bit of objective data (measurements).
This is not even close comparable to the elaborate and helpful speaker reviewers, which while by themselves are also 50 % subjective/50 % objective review/recommendation, but at least I can draw on some really helpful measurements and explanation to make up my own mind.
How easy was life here, when it was only giving recommendations to dac/amps, mainly by measuring distortion/noise ...

Here it is, for the last 4 reviews/recommendations "Oh my favorite harman icecream response" and "distortion could be better".
 

wasnotwasnotwas

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You are going fair bit far with that statement. :) The preference curve was determined in controlled listening tests, not a computation or modelling. So it is what people heard. There is a degree of accuracy of course and the curve is heavily filtered but still, the heart of it is listening tests. If we all use the same then there is hope that one day we all experience music the same way and as intended.

Perhaps so, but I also dont like pronouncements like ... "if there are big deviations from the Headphone Harman Curve that it won't sound right". Seems a bit personal, to me, to make such blanket statements. Lets leave it as "it has significant deviations from the Harman Headphone Curve" - we all get what that implies.

EDIT- I should clarify, Im not anti Harman. I just know I have listened to many HP stock that sounded fine. They have been improved in most cases with EQ, to or near Harman. But that doesnt stop them being enjoyable to folks that either cant or wont EQ. "Wont sound right" is a nonsense. "Wont sound right to someone who prefers XXX target curve" is accurate.
 
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amirm

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Is it so hard to do the measurement suite again after EQ?
As I have explained a number of times, yes, right now it is hard. The audio Precision software that is used for measurements does not have any kind of parametric EQ. The signal is generated by its own hardware so it is not subject to any EQ in software/Windows.

It does have a mechanism to enter a calibration curve but I have no way of exporting my EQ from Roon into it. It does have a very crude curve editor and I could sit there for an hour to create a curve. Alternatively I can run the sweep signal in Roon which is what I did. The results are not that good so I have not yet post them since the post processing is not the same as when AP is running the test.

As with speaker testing where distortion tests took some time for me to develop and standardized, some patience is needed for headphones. FYI I didn't show you post EQ distortion tests for speakers either! :) So not fair complaining about headphones in that regard.

For now, you can predict the increase distortion somewhat from looking at the dual levels I am showing:

index.php


The red graph is a result of 10 dB amplification. That shows you the impact on the distortion relative to EQ levels in play.

Bottom line, I will develop more tests in the future. For now, I have a terrible backlog of expensive headphones that have literally been here for months and I need to get them done and back to their kind owners. I can't use too much time to develop tests.
 

sam_adams

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View attachment 100186@amirm I would suggest place the headphones a bit further back in this direction to gain some extension and more representative measurements.
Try this on the real human head as well and see how the sound changes.
But I'm 100% sure whether this is already optimized placement or not. Maybe this is the best that you could do. So this is just a suggestion. If it's already done. All good.

I was wondering about the reference @amirm was making regarding reflections that was effecting the FR. Now I see where they would be coming from, the metal plate surrounding the test pinnae. It seems that the lack of 'squishy bits'—as in "Real Human Flesh"™ ©—surrounding the test pinnae could be responsible.
 
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