Head-Fi Contradicts InnerFidelity Sony MDR-Z1R Measurements

Out on my morning web surf and I stumble onto a bombshell on the front page of Head-Fi:

"Sony MDR-Z1R Measurements: Head-Fi HQ’s compared to InnerFidelity’s"

That article links to a much more comprehensive post in the Z1R thread by Jude Mansilla, Head-Fi's Founder. It seems Jude's measurements are somewhat different than mine, particularly in terms of the peak in response around 10kHz. Here are the two plots in question:

InnerFidelity Frequency Response

Head-Fi's Frequency Response

It's important to note here that the Head-Fi plots are compensated plots and are best compared with the top blue and red traces in the InnerFidelity plot. It's also important to note that it is somewhat unwise to compare plots between different systems as they will vary. And lastly it's also worth noting that Head-Fi's system is of excellent quality. There's a description in the linked post above and I'm jealous...very nice gear.

In Jude's post he concludes:

What's our conclusion? Right now, we'll assume that perhaps Tyll has an outlier Sony MDR-Z1R. n=3 across two different measurement setups isn't enough to come to a conclusion. If Tyll will allow us to measure the MDR-Z1R he has, that would certainly be helpful. We'll also be receiving at least one other production MDR-Z1R, and we'll measure that, too. Based on what we've heard here (and also on hearing other MDR-Z1R's)--and based on many reviews/impressions that predated the publishing of Tyll's measurements--we'll also assume for the moment that our impressions and measurements are more representative of the MDR-Z1R's that are out in the wild.

Bit by bit:

"Right now, we'll assume that perhaps Tyll has an outlier Sony MDR-Z1R."

I've found assuming a poor idea. Usually I'll try to think of a number of possibilities and then move toward gathering evidence that points towards a conclusion. It could be that I have an outlier, but it might be that Jude's compensation curve has a big bump at or near 10kHz. I'd certainly like to see the compensation curve used, and I'd really like to see the raw measurements from his HATS (head and torso simulator).

"If Tyll will allow us to measure the MDR-Z1R he has, that would certainly be helpful."

Absolutely, and back attcha. Let's trade headphones and re-measure. I'll shoot Jude an email.

"...we'll also assume for the moment that our impressions and measurements are more representative of the MDR-Z1R's that are out in the wild."

Yeah...that assume stuff. Given other measurements available on the web, I think there is a significant peak at 10kHz. Let's take a look:

From Speakerphone:

Raw Frequency Response Measurements 170616_Blog_HeadFiMeasurements_Measurements_SpeakerphoneRaw

Cumulative Spectral Decay 170616_Blog_HeadFiMeasurements_Measurements_SpeakerphoneCSD

From PMR Reviews:

Frequency Response

From Superbestaudiofriends.org:

Frequency Response

CSD Left

CSD Right

CSD Foam Coupler

From SBAF Member spawth:

Frequency Response

Again, comparing measurements from a number of rigs is rife with potential miss-assumptions, but it does look like there is a significant feature at 10kHz in all of them.

Since Jude has measured three Z1R headphones on his system that measure similar to each other and without such a feature, I'm lead to believe his system is measuring repeatably. Possible sources of this error might be (in order of likelyhood from my experience):

  1. The geometry of his head may be different than mine and may not measure the 10kHz area the same as mine. It's clear from Audeze's comments about measurements on various systems that this might be the case.
  2. His compensation curve has a feature at 10kHz that is reducing the peak in the headphones. Peaks at or around 10kHz are common in these curves. Here are commonly used DF and FF curves, both show elevated high frequency energy or peaks:
  3. Frequency response repeatability at high frequencies is know to be riddled with error. Small differences in headphone position can make all the difference. It's possible that Head-Fi's method for positioning the headphone on the head for measurement is generally different than mine and may result in differences in high frequency measurements.
  4. The headphones that i have are indeed not representative of currently produced product.

Personally, I'm inclined to believe #1 above, but I'd really need to see the raw data to move forward on that thought. Jude willing, I'd be very happy to pursue this further.

I'd love to hear your thoughts in the comments below!

thefitz's picture

Even Jude's measurements show a spike at 10kHz, but none of them (except maybe the last one) show a spike that's like 6db higher than the 3kHz spike. In fact, in most graphs, the 10kHz spike is a db or two lower than the 3kHz one.

Maybe's picture

The Speakerphone graph is uncompensated. Diffuse-field compensated it shows quite a peak at 10kHz.

See: https://lh3.googleusercontent.com/-tviKM8RJVsY/WKm3RCV4M8I/AAAAAAAAFh4/H...

I'd say this specific measurement is the most comparable to Tyll's and Jude's setup, as the others are all flat plate couplers whereas Speakerphone uses a Cheek and Pinna Simulator.

Additionally the CSD plots suggest ringing at that frequency across all the systems.

spwath's picture

I made the last measurement. That spike is much bigger than others. I would not necessarily trust mine completely. My measurement rig is a piece of leather and some felt tapped to a broken lamp. But it does seem relatively accurate for most measurements.

thefitz's picture

... as evidenced by being so insecure that his mods remove references to SBAF. I mean, that's insane.

Magoo's picture

I think all of us would just like some consistency in Measurement AND Production. These TOTL hp's cost waaaay too much money for these differences to show up.

It's will interesting to discover where the inconsistencies lay....maybe they are in both Production and Measurement???

ultrabike's picture

I don't think there is a consistency problem with these headphones.

Every measurement rig will have discrepancies when compared to another measurement rig. But several headphones of the same make and model should measure very similar in the same rig.

Based on what we are seeing from even different measurement setups, I think it's clear that the headphones Tyll has do represent the product well, and Jude's measurement rig paints a better picture than most every other measurement rig from a variety of different sites.

darkswordsman17's picture

I can't agree simply because we have a distinct lack of hard data to support things either way. I would guess things have improved, especially in the past just few years it seems like there's been a movement towards tangible objective improvements across the industry, and I'd be willing to bet that has helped improve quality consistency. There's likely to be outliers though, and some of these companies treat things more like a boutique production, where variability almost seems to be a desired trait.

I really liked how the HD-800 came with frequency response plot of each individual pair for the owner. I wondered how many pairs were tested and compared to the Sennheiser measurements.

ultrabike's picture

Plenty of HD800s have been tested. The HD800 in particular is a very consistent headphone across samples when measured.

Same could be said about HD6x0, PortaPros, KSC75s, HD202, Beyerdynamic classic line, ...

Measurement setup variation can be dramatic however. Specially when using a body and head model and when lacking experience, which unfortunately I think is Jude's case.

darkswordsman17's picture

How well did they matchup with the Sennheiser provided plots?

Definitely there have been some that are the model of consistency, which is why I don't know that it is a big issue, although in this sorta odd high end boutique niche they've always seemed a bit...off. Some definitely were better (one reason why the HD-800 is so lauded even though plenty of people say it isn't quite to their liking) than others.

AstralStorm's picture

They do match up with regards to peak locations and general tilt.

There is a plenty of high frequency magnitude variability due to pads being "broken in" or not as well.

All of the above is why I personally measure the headphones by ear as a check and recommend everyone to do that. It's a reasonably quick process involving sine sweeps and results often match ones from good measurement rigs almost to a point. With minor wideband differences in compensation. (Less than 3 dB.)

halcyon's picture

and results beyond 8K are infamously prone to small adjustments and changes from HATS, mic positioning, etc.

They might be all right.

The final proof is in the (eating of the) pudding.

spwath's picture

Do note my measurements are of the same pair as the SBAF pair, but different measurement rig

francisk's picture

Do take into account of the graph scaling which obviously has a great effect on how the graph looks. It's not a very good idea to compare graphs that's scaled differently.

ultrabike's picture

Were is the like button when you need it.

This is a great observation. Graph scaling is a tool used by some to make things look better or worse.

Journeyman's picture

IMO the best way to show off a new measuring rig is comparing it to standard used by most enthusiasts, in this case Innerfidelity.
Jude needed something to call attention to his new fancy rig and that's about it.
Anyway lets asume I'm biased because I don't really like or want to like Jude and what Head-Fi represents, glad at least Sony is not their sponsor, some companies don't really need all that hype train.
This will end with something a long the lines of "Oh we made a little mistake and we are sorry for all the commotion but look we promise we will use our new rig better next time"...

tony's picture

Jude says he's a fan of the Sony.

I'd say he's a big fan of everything, he only uses superlatives.

Tyll & Co. are the Scientists in the Room.

Has Sony Hi-Fi ever been anything more than Mid-Fi?

Sony's A7 Camera is quite good by Canon 5d Standards, their Pro Video stuff is pretty good ( not quite a RED ).

People buy Sony because they want Sony, they've never heard of Audeze or Focal or probably Stax for god's sake.

I'll bet these Sonys are better than those pretty Beats.

Tony in Michigan

ultrabike's picture

Jude is a Fan of Head-Fi

darkswordsman17's picture

Sony has made some pretty boutique audio gear over the years. Sure a lot of their stuff is fairly generic consumer stuff and I've found it to be somewhat lacking.

But even in headphones the R10s and Qualias have legendary status. Something interesting to note is that there was even talk about bass light/heavy versions of I think the R10s, so it seems that there were production differences. I always found it odd that people seemed ok with that, when to me it seemed to indicate an issue, and on such an expensive item.

ultrabike's picture

I've hear a "legendary" R10. I have a lot of respect for the owner, but it was not just bass lite. It was a complete mess. I was told the driver degrades over time. If that is the case, it is likely that this was not a production difference issue. It was a production longevity issue.

I don't think that's the problem in the MRD-Z1R case discussed here. Those things just came out.

Again, I could be wrong but I don't think this is a Sony production variability problem. I think it's more likely that Jude lacks experience in audio characterization, and may lack some critical listening skills. He is pretty experienced in running audio forums for commercial purposes though.

John Grandberg's picture
I've owned two different sets of "bass heavy" R10s over the years. They were beautifully built and sounded... "interesting"... but I think nostalgia and rarity have elevated them to a status they don't deserve. That said, Sony can make some good stuff - the ZX2 player is killer.
ultrabike's picture

Yup. I think R10's will be all over the place probably due to driver degradation. Here are my impressions when I heard them:


I didn't measure them, but it seems Bill-P did:


AJ's picture

@Tony in Michigan,

I always enjoy reading your comments.

Wanted to clarify on the Sony comment. I do own stuff from Audeze, Hifiman, Sennheiser, JH Audio, Stax, Shure, Cypher Labs, Alo Audio, Chord and so on and the Z1Rs are my first Sony audio purchase in a long time. Yes they are largely a midfi company but from time to time companies do surprise with innovation (Focal was a surprise recently with their headphones while they have been good with larger drivers). While this thread is about measurements and the discussion is both good and important, I am curious where this topic goes because I am impressed with the Z1Rs. I enjoy listening to music on them and was surprised by how negatively they have been discussed here. This hasn't happened for the longish time I have been following this site. I think Sony has come up with a good product and feel sad about them getting this negative buzz.


tony's picture

I'm certain that most folks will be delighted with their Sony Gear, just like folks being satisfied with their Toyota cars. ( I've always wished that my GM could build as well as Toyota )

If I were Sony, I'd ignore the high end of headphones and push for a Global acceptance.

Measurement data is a wonderful catalyst for deep rooted argumentation that only more measurement will begin to resolve. I'll trust Tyll & JA when it comes to measurement but I'll buy on sound quality and probably ignore the graphs. ( kinda like Katz )

This topic goes to Insanity unless there is repeatable consistency which seems unlikely because these transducers are working with such low energy levels. ( just a tiny increase in energy will yield 3db difference).

I'll simply apply digital signal processing to accommodate my personal Ear's response characteristics and live happily ever after.

These latest high end headphones are secondary to the much larger Format change that we're about to embrace : "Streaming", we're about to have access to much higher quality sound sources.

Tony in Michigan

HiFiArt's picture

Hiya Tony in Michagan:

What about...

1) Sony MDR-R10 "King" Headphone

2) Sony MDR-7520 Headphone (and other Sony Pro headphones used is broadcast studios worldwide and headphone entusiasts also)

3) Sony SS-R10 Electrostatic Speakers

4) Sony SS-M9ED Loudspeakers

5) Sony TA-NR1 Power Amplifier

6) Sony TA-NR10 Power Amplifier

7) Sony SCD-1 SACD Player

8) Sony DAS-R10 DAC / Matching CD Drive


How's everything in Michegan?

tony's picture

I finally got round to looking up all these Sonys on Google images.

This is nice stuff, indeed.

But it's not High-End like the stuff you'd see at LAAS 2017!

True HighEnd stuff sits on the floor, not in Racks.

There are no $50,000 Sony interconnects or $25,000 to $125,000 Sony Reference Speaker Cables that need 300 to 400 hours of proper break-in. ( maybe considerably more )

I didn't see a Sony Record Player, hmm, can't quite be HighEnd without a proper Vinyl playback with $15,000 MC phono pick-up, can it?

To top it all off, Sony has way too much distribution, high-end stuff like darTZeel have only "One" dealer in the entire USA ( for gods sake ), it can't be high end if anyone can buy the stuff. (can it?)

Sony is nice stuff for "Everyman" not quite twitchy enough for true High-end believers.

Tony in Michigan

ps. Although, a person might get "special" dispensation if they happen to buy some of those Sony SSR-R10 Electrostatic Speakers.

sarin's picture

next time get your fact right in first place..don't try to cover up like this.Or apologize perhaps??

tony's picture

what am I to apologize for ???

Tony in Michigan

AstralStorm's picture

"Mid" fi and is such a silly term. It is devoid of meaning because everyone moves the goalpoast.

There are no out of the box "hi-fi" headphones out there. They don't exist. Not even boutique top of the line stuff. (This includes Stax, ZMF, Audeze, Hifiman and top Sennheisers.)
Best ones can be made high fidelity either with a mod or equalizer or both - and then a spatial simulator on top.
In fact out of the box the closest seems to be Sennheiser HD 650/6xx or ZMF Eikon. Note few thousand dollar difference between these two, and neither are the most expensive.

The definition of high fidelity involves a played back recording being true to life. There are no tiers in it, only smooth comparisons.

MDR-Z1 are decent but definitely nowhere near the best bang for buck you can get in these terms. The resonance is audible but not getting to terrible levels. However, such issues are very hard to get rid of, even with mechanical modifications. The FR needs eq to sound lifelike.
About the only place they excel is at bass (except subbass) reproduction.

AstralStorm's picture

They are definitely better than anything Beyerdynamic or AKG released ever.

Luigi's picture

in my experience, having extensively tried almost every hp under 2500 bucks, i can certainly say that the akg models, from k712 to the new K872, are in another world in comparison

darkswordsman17's picture

This (the Sony as well as the issues seen with the Audeze and Focal) might be just some fairly minor hiccups in early production runs or even fairly anomalous units, but I think this might be a symptom of an issue that seems like more and more people are starting to notice. Companies are definitely listening to feedback (and especially when it can be pointed to objectively, they know what to address), and often release products that "fix" the issue. But, that is becoming an issue itself, in that has consistently come with a substantial price increase. So its like they get to have people beta test a production run, tweak it, and then since they fixed some issue they can justify a price hike.

ultrabike's picture

I think there is some evidence that Audeze had (and may continue to have) issues with their drivers.

I think Focal send a Utopia headphone to Tyll that was not very representative of the final production unit. But what is out there in the field does seem very consistent. I measured two Utopias, and both units measured remarkably the same. This BTW was repeated and shown by Tyll on a separate article in which he measured way more than two Utopia cans, and those measurements were fairly similar.

I don't think Sony had some hiccups though (aside from apparently producing an overpriced lack luster product).

Argyris's picture

We'll see how the measurements compare when Jude's headphone makes its way to IF (and visa versa).

However, does anybody else think it's a bit crappy how Tyll wasn't contacted about that article before it hit the front page of HF? Normally when you have a big discrepency like that and want to make a story about it, it's common courtesy to reach out beforehand to the person you're referencing and trade notes, or at least let them know what you're planning to. Not to mention, the article itself sounds vaguely accusatory and incredulous. It's as though Jude is questioning how Tyll could have come to the conclusions he did and is using his (Jude's) own measurements to prove a point, rather than highlighting a measurement and impressions discrepancy and suggesting possible causes, as Tyll has done in this article.

Tyll Hertsens's picture
Seriously,I've got no problem what so ever with Jude posting as he did. I might have done the same in his position. When you have a soap box, that's where you talk from. Really, it keeps the dialog out in the open and that's a good thing.
donunus's picture

I agree with this comment. It's best to put everything out there to get to the bottom of things. Everybody learns more in the end.

maelob's picture

I would definetly like to see a standard in the way Headphones are measured across the board. At the end is a good thing that Tyll and Jude collaborate on this issue. also sorry to say that I like the Z1r lol

donlin's picture

Rather than Tyll and Jude exchanging headphones for measurements, I'd much prefer they listen to each one side by side and compare how they sound. In the end that's all that matters.

Tyll Hertsens's picture
Hm. Good point. I'll see if I can work that out.
raulromanjr's picture

I like Head-Fi and I like Innerfidelity. I appreciate how you keep it professional and don't get trapped into what some people want to see (a bit of drama). If I read your you right through what you publish, you probably find this interesting and want to explore it to reach some better understanding for you and your audience. I'm sure Jude would find it equally beneficial for you two to work together on this. Looking forward to the process and I hope you both document your interactions, research and conclusions on this matter.

me klasse's picture

Despite not being a 100% reliable method, especially when ear simulators are involved, one can always compare the measurements of other (known to be consistent from pair to pair) headphones in both rigs (Innefidelity and HeadFi). If they differ similarly in the 9-10kHz region then the rigs/compensations are responsible for the exposed differences on Z1r measurements.

Here we have Innerfidelity (thicker trace) and HeadFi(thinner trace) measurements of Z1r scaled and overlapped so the difference is clearer:

Here we have measurements for the consistent HD650 on both rigs for the sake of comparison (IF:darkblue-red / HF:lighter blue): https://s23.postimg.org/nl0a6bfh7/hd650_Tyll_Jude.png
We can see a ~10dB difference in the 9kHz region here.

Here's also the same kind of graph comparing Utopia measurements on both rigs (IF:darkblue-red / HF:lighter blue):
We can see a ~10dB difference in the 9kHz region here as well.

Me x3

ultrabike's picture
This IMO is a very helpful comment. It comparatively shows how the different rigs produce different results in the absolute sense. I don't think it's easy to compare results from two different measurement rigs.
ADU's picture

It comparatively shows how the different rigs produce different results in the absolute sense.

Not sure I agree with this.

I believe the plots being compared in me klasse's post above are both compensated/corrected.

To get a better feel for the difference in "absolute" measurements between the two rigs, I think you'd have to compare the raw _uncorrected_ FR plots of both systems. Or possibly FR plots corrected with the same _type_ of compensation curve.

Diffuse Field is the most common. But I believe Tyll still uses an Independent of Direction HRTF for all his compensated plots.

I don't know what Jude is using for his compensated plots, but I sort of doubt that it's an IoD function.

It has been stated here before that the Head Acoustics IoD correction curve (which is what Tyll uses) results in more prominent peaks in the 9 to 10 kHz range on compensated plots than the Diffuse Field curve. That's because the IoD curve has a "dip" in that frequency range, rather than a peak...



I don't think it's easy to compare results from two different measurement rigs.

I'd agree it's a difficult proposition under any circumstances, unless you really know your way around both systems. Using the same type of compensation curve should theoretically make it somewhat easier though.

ADU's picture

I don't know what Jude is using for his compensated plots, but I sort of doubt that it's an IoD function.

After looking at the fine print in Jude's post, it appears that he is indeed using some sort of Diffuse Field compensation...


The frequency response measurements reflect diffuse field correction applied via the APx555's input EQ.

That may account for some of the difference, since Tyll is using a different type of compensation curve, namely the Independent of Direction HRTF, which is probably not as forgiving in the 9 kHz range as the DF curve.

Jude is also using a different head & torso simulator, the G.R.A.S. 45BB-12 KEMAR, while Tyll is using one by Head Acoustics. The differences between the two HATS systems could perhaps be somewhat mitigated though if they were both using comparable DF compensation curves appropriate to each system.

And as others have pointed out, it looks like Jude is probably using more smoothing on his compensated plots.

Since they're using different HATS systems (and probably also different smoothing), I would not expect Jude's raw/uncorrected plots to look the same in the treble as the raw Inner Fidelity plots. There could be more of peak at 9 to 10 KHz on Jude's raw G.R.A.S. plot than on his compensated plot. Or it could just be smoothed away.

Now, about those Audeze and Focal HPs... ; )

ADU's picture

To get a better feel for the difference in "absolute" measurements between the two rigs, I think you'd have to compare the raw _uncorrected_ FR plots of both systems. Or possibly FR plots corrected with the same _type_ of compensation curve.

I need to correct my above statement.


If there's no difference in sound quality between the two headphones being measured, then the raw plots with no compensation should show the difference (if any) between the two HATS systems.


Performed correctly, Diffuse Field compensation should show the difference (if any) between the two headphones, irrespective of any differences between the two HATS systems.

Sorry for any confusion on this.

AstralStorm's picture

Diffuse field compensation is not quite a standard you make it. Unless you have the actual compensation curve, you're essentially guessing as to what it is.

Three Toes of Fury's picture

.and post opinions...good and bad.

It appears there's a bit of a trend forming where folks get defensive when something critical is posted lately..especially involving waveforms..and then question the process to defend the gear they like, or perhaps have vested interest in.

Absolutely the science behind measurements..and methods used..should be examined and understood. And provide comparisons where/when possible.

However the reviewers that we seek input from...and I would consider Tyll and Jude tops on that list...should be able to post their: analysis, findings, data, review, suggestion, or criticism, without worrying about back-and-forth questioning of their review or stance.

The talkbacks on this site do a great job of both: agreeing with tyll in times that he's critical as well as offering differening opinions when folks own and love the gear that he didnt connect with.

Peace .n. Living in Stero


HiFiArt's picture

Let's look at that SBAF Graph.

From my eye, the frequency reponse (FR) looks ok, from 20 Hz to 70 Hz. (+/- 3dB, ok +/- 1). Then it begins to fall off rapidly until 2K.

From 60 to 10 kHz there seems to be a major suck-out, and the 10K I see as a recovery in FR. Ok, there's a bigger suck out from 2K to 10K.

It reminds me of the frequency response of the Sure SM-58 Vocal Microphone.


Only the FR of the '58 is better!

What's up with headphones?

You wish an transducer quality that is at least equivalent to a microphone.

Let's look at a Earthworks M50 (not a great one but ok) :


3Hz to 50kHz ± 1/-3dB (Frequency Response)

140dB SPL (Max Acoustic Input / Playback SPL with low relevant THD) so you can do 24-bit (23.25)


tinyaudio's picture

you're really comparing apples and oranges here.

You can not - ABSOLUTELY NOT - compare frequency responses of microphones and loudspeakers, let a lone microphones and headphones.

They are not measured the same way, and represent very different qualities of the specimen.
The only thing they have in common is that they can accurately be called "frequency response".
But this term describes different things for headphones/speakers and microphones.

AstralStorm's picture

I do not agree with the statement at all.
Guess what you measure headphones or loudspeakers with? Is it perhaps a microphone?

In the olden days, the measurement rigs compensated their capsules more mechanically than digitally, but in the end, there's always a microphone.

Now headphones vs loudspeakers, we have additional variables, like the room, distance, positioning of the microphone and so on.

HiFiArt's picture

For comparison, let's look at the Magico M5 Loudsepaker:


Ok, it's got a bit of a bass suckout (+/- 2 dB) at around 40, which bass heads won't prefer.

But we're literally talking about deviations of about 1 dB (or at most 2.5 dB) from a reference line for the entire frequency spectrum (20 Hz to 20 kHz).

Let's look at the Magico Q5 Loudspeaker now:


The graphs are equivalent to Tyll's now, visually.

Shouldn't headphone FR be like this?


At least to sound representative of the recorded frequency spectrum.

tinyaudio's picture

Your graph shows a roughly linear frequency response in the audible band (20 Hz - 20 kHz).
This is roughly the target for loudspeakers, yes. (There's a bit more to it to make a speaker that sounds good in a room, but a linear frequency response as measured in an anechoic measuring chamber is a good starting point)

However the target for headphones is very, very different. Mostly because you can't really measure headphones the way you measure speakers - you measure headphones on artificial heads, and not with a measurement microphone in an anechoic chamber.
This means that the various resonances of the ear canal etc play a great role.

Long story short:
The target FR for headphones as measured on a dummy head (professionally called: coupler) is very much not linear.

For further research read up on Harman's latest research concerning this very topic (ideal frequency response for headphones, conducted by Dr. Sean Olive and Todd Welti)

AstralStorm's picture

There is no "target" for headphones, even if we're talking average HRTF over big populations which nobody has measured ever.

All alleged "targets" are guesswork by someone who thought "it sounds right" or more scientifically, derived by comparison with reference speakers in a reference room.

AstralStorm's picture

Unless you're talking IEC curves which are known to be a mediocre guess and there are a few revisions thereof for various measurements too.
Even then, the exact compensation curve and measurement technique has to be specified. There's an IEC standard for that!

HiFiArt's picture

Ok, I'll disagree with you on the first point ("you are really comparing") and take up your second.

Shouldn't there then be a frequency response chart that shows deviation?


I don't have a Neuman KU81i or KU 100, so I don't know how far down the microphone capsules go on a typical binaural head used for headphone measuring - the best I've got is a Sennheiser MKE 2002 which has the microphone capsules, externally.

It's a pretty shit device, but was a pretty fun toy.

Others might have much better binaural heads for headphone measuring : it's typically used for binaural enthusiast (re: nature) recording.

I gave a pretty shit microphone comparison.

For example, if you want to record 100K, you get something like a Sanken.


It's FR is pretty shit, like headphones, but you can at least digitally introduce a compensation (given you have a recorded reference).

It's got a wider FR than a Neuman, though.

Do you really want more than a +/- 0.5 dB variation?

I'm not sure I'm really into Harmans headphone response curve.

For playback their M2 Monitor, recommended by Franco Filipetti, is apparently a pretty decent bargain.


The reason I'm bringing up speakers and microphones on the topic of deviation is that I believe it brings something to offer to the conversation.

If the microphone capsule is not too deep on the binaural head (not a full represenation of a ear, full canal, drum, etc.) then you will at least get some direct recorded sound.

Then, like a loudspeaker played back in a room, you just have to deal with refelctions, etc.

Most Stereophile measurements you will find (I know this is InnerFidelity) are done in home garages and such (and not anechoic chambers) with microphones like the ol' DPA (now B&K) etc.

As a consumer, I don't expect a lot of variation, unit to unit (as do not most, here), and I would like a flat FR.

I am a big collector of headphones (as they're cheaper than speakers, and easier to store: less space), but was most disappointed when I heard the Focal Utopia headphones.

Actually, completely disappointed.

I was thinking of purchasing the Focal Grande Utopia III EM Loudpeakers for front and Focal Scala Utopia III 2's for rears for a home theatre, and couldn't believe how shitty the Utopia headphones sounded by comparison.

Perhaps that's why I got to comparing headphones and speakers. Same manufacturer, same product name. :)

As to headphone FR, in particular, a pair of Atomic Floyd Power Jax headpones which I purchased, which I found quite durably made - a great in-ear headphone feature - had absolutely magnificently poor FR, in terms of deviation.

Oh well, life is life.

Since microphones are used to record headphone FR, I think it is fair to compare microphone FR with headphone FR.

Since headphones are often touted as an inexpensive replacement (the same quality for less money) for speakers, I think it is fair to bring up speaker FR as opposed to headphone.

Sennheiser for example, made really wonderful microphones before making a decent consumer headphone.

Their MKH 800 48 is really nice, today.

I had some of their headphones like the 560 and 560 II Ovation, and while they were beautiful, and luxuriously comfortable: the sound was shit.

It wasn't really until their 580 that the sound of their headphones got good, and comparable to a Rotel / NHT (non Michi) system.

In terms of binaural playback their 800 is stunning!

The full 360 sphere is properly played back (from a recording with a Neuman KU81i or 100) unless every other headphone.

I love my stax, but I'll give it to Sennheiser for making both a great collection of microphones, and a decent headphone too.

Likely, I'll pick up this Sony, but I sure wish headphone FR with respect to flatness would be improved.

It's such a simple system. +/- 0.5 dB should be achievable.

ADU's picture

You echo the frustrations of many of us.

With proper correction, I believe a flat frequency response target for headphones is possible. And it's one of the things I'm working toward for my equipment. But I'm an optimist. And only do this as a hobby.

To really be useful, a headphone target probably needs to be adaptable for different measurement systems (HATS), and also different designs (in-ear, on-ear, over-ear). And maybe also different room simulations.

Harman's headphone target is certainly a step in the right direction. But its application is limited, because it was only designed for one measurement system (G.R.A.S.). And some of us feel that its modeling of room FX is not accurate enough, and too subjective.

I haven't heard the new Focal Utopia btw. It employs a fairly radical new design though (based on what I've read here). And there are bound to be some growing pains associated with that.

AstralStorm's picture

Personally, I wouldn't model room effects at all (only keep partial HRTF), as this limits what headphones can reproduce - they are much worse for video games that use advanced sound positioning systems then while not being notably better for recordings mastered for speakers.
You will want a spatial simulator regardless for the latter.

tinyaudio's picture

We own a KU100 at the company.

The Neumann KU100 is a binaural microphone, but it is absolutely not usable for headphone measuring. It's ears are "hard" (they do not fold like real ears), which makes proper placement of the headphone impossible for all but the largest Over-Ear Headphones. You could maybe stick a HD800 on there, but not anything smaller.
Its microphones are located at the EEP (ear canal entrance point), meaning that while there is a proper concha ("ear"), there is no ear canal in this dummy head.
The purpose of the KU100 is to create dummy head recordings, and for this ear canals are not needed.
But they are necessary for proper headphone measurements, because the resonance inside the ear canal changes with the acoustical impedance (not the electrical impedance) of the headphone.

Also the ears of the KU100 are not airtight, so when you try to measure a headphone on it you will always find it lacking the proper seal to achieve linear bass. (Bass is inherently linear below the resonance frequency of the driver as long as the volume between ear and headphone is sufficiently sealed and smaller than the wavelength of the sound, this is called the "pressure chamber effect"). The KU100 does not have an airtight ear assembly, which makes it impossible to achieve any kind of seal with a headphone.
That's just because it is designed as a microphone, not a measurement rig.
The pressure chamber effect is also the reason for why you don't have to concern yourself with reflections - because the wavelengths are much longer than the volume you're working in, practically all of the audio spectrum (and in the case of in-ear monitors: ALL of the audio spectrum) is happening before the lowest "room mode", in other words before you have to consider sound as a wave, an not just a change in pressure.

Proper measurement rigs are something like the G.R.A.S. KEMAR, or Tyll's HATS. They have ear canals with the exact same acoustical impedance as an actual ear canal + ear drum has.
They are also specified in the IEC711 / IEC318 (and a few other norms).

The problem is that "Flat" FR is not the goal for headphones. A headphone that measures completely flat sounds absolutely wrong.
That is because when you listen to a linear speaker and would measure the FR that arrives INSIDE your ear, it's not linear anymore (due to a lot of effects).

The actual target for headphones is a matter of debate.
The discussion for the target FR for speakers has been settled ("linear on-axis FR in an anechoic chamber, controlled sound power"), but the discussion for headphones is ongoing.
Researchers have opted for a free-field compensation curve in the past, changed to a diffuse-field compensation curve in the 80s and 90s (if I remember correctly), and Sean Olive's current research has found different results.
Audeze has a different target curve, Bose uses a different target curve again. Sennheiser uses a modified diffuse-field curve as their target for the HD800, and other target curves for other headphones.
Since there is no general consensus about the target FR of headphones, I find it impossible to compare "compensated" frequency response charts, simply because the compensation itself is not agreed upon. And this is also the exact reason why Tyll's and Jude's measurements appear so very different - they are using different compensation curves.
I don't think Tyll's IoD-compensation is a good compensation curve, which is why I never look at his compensated plots but only at the actual uncompensated, "raw" measurements.

Luigi's picture

Hey Tyll, Looking your graphs and listening to your suggestion, i've bought my best audio equipment, and my liking are similar to yours, excepts for the highs quantity. I love bright headphones, but the problem in these hp is not only in that spike in the highs, but also (and for me this is the most important issue) that incredible amount of bass that orribly bleed into the Mids. That kind of meaty, slow timbre that suffocate every voices. We can speak about the evidences, but everybody knows that a Momentum is a brown coprolite, every beats model will never be a good choice for a music lover, and in the Sony lineup there's not a single masterpiece of a headphone like audeze can do. Jude is a sales man and sometime this isore evident. Sorry for my english.

sszorin's picture

I read once an observation on the evolution of an audio buff. It begins at the first stage of a hi-fi newbie : "Give me the bass !", then it evolves into more sophisticated "Give me the mids !" and it reaches peak with "Give me the treble" ! Some people never leave the launch pad of bass.

audaCITY's picture
sszorin's picture

The creators of these headphones made a design error. 40mm driver of ORA GQ is not large enough.

dumbasstyll's picture


tinyaudio's picture

you being a complete troll aside - he did put the AKG N90q on the wall of fame just recently. So there's that.

But nevermind, you're here to troll.

sszorin's picture

Did Tyll trashed headphones which you have and value ?

Corsair's picture

this will be good for everyone (including sony and consumers) if together jude and tyll can elucidate what's going on. I'm a little surprised given how well they know each other and given what tyll has done for the community that jude didn't go to tyll first. When I first read jude's post my impression was that it smacked of arrogance (look what i found that tyll didn't). maybe that's innacurate but that was my feeling. regardless, it might have been far more expedient had jude immediately just reached out to tyll before writing a lengthy and time and energy consuming "well, this is what i found" post. If he had gone to tyll first, then it would have politely given tyll a chance to correct his error, and jude wouldn't have had to lift a finger. But if it turns out tyll's findings are more accurate than jude's, then the onus is on jude. Either way, jude's approach was not one i would have taken. Tyll seems to have taken the higher road in the manner of his response. thanks for that, tyll.

ADU's picture

This is still not an apples to apples comparison imo because Jude appears to be using more smoothing. But it's getting closer.

First Tyll's graph. For those who can't read, the raw/uncompensated plot is the gray curve...


Here's Jude's raw plot scaled to about the same dimensions...


And here's another higher resolution graph of Jude's raw plot...


So what say you all? Did one of these guys get a bad unit? Or is it differences in rigs, operators, smoothing, etc.?

There are obviously differences between the two in the treble. But we can't blame the compensation curves for that now, because both plots are uncompensated.

tinyaudio's picture

Am I missing something? Where did Jude publish his uncompensated curves?

ADU's picture

Am I missing something? Where did Jude publish his uncompensated curves?

I found Jude's uncompensated plots here...


If you click on his thumbnails, it will display the larger graphs. These were posted in response to Tyll's comments here...


I'm still playing catch-up on this discussion as well btw. So I don't know if Jude has also posted _unsmoothed_ versions of his graphs yet.