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Neumann NDH20 Review (Headphone)

respice finem

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Very interesting, especially since this is a headphone Neumann recommends for mixing... So it should be as neutrall as it gets.
Knowing the attitudes of Neumann, this is probably as neutral as Neumann (Sennheiser) is able to make it...
 

xykreinov

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I have to say that they look damn good on Amir's photo. Every other marketing photo hasn't sold it so well.
My dad had one. They do look better in person. Too bad the sound wasn't there. One of the weirdest sounding headphones I've ever listened too. I think it can be summed up as an uncanny valley.
 

GWolfman

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@amirm Maybe I missed it, but how was the comfort (on your head)?
 

Maiky76

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This is a review and detailed measurements of the Neumann NDH20 closed back headphone. It was kindly sent to me by a member and costs US $499.

The NDH20 is an attractive and solidly feeling headphone:
View attachment 158331

It weighs slightly above average but per above, it felt fine wearing it:

View attachment 158332

The removable headphone cable is light but has this spring action to it that was annoying. I literally had to put something on top of it on my desk to keep it from interfering with my mouse.

Note: The measurements you are about to see are made using a standardized Gras 45C. Headphone measurements by definition are approximate and variable so don't be surprised if other measurements even if performed with the same fixtures as mine, differ in end results. Protocols vary such as headband pressure and averaging (which I don't do). As you will see, I confirm the approximate accuracy of the measurements using Equalization and listening tests. Ultimately headphone measurements are less exact than speakers mostly in bass and above a few kilohertz so keep that in mind as you read these tests. If you think you have an exact idea of a headphone performance, you are likely wrong!

Fitment on the fixture was VERY difficult. It would not fully surround the artificial ear, and I could not get it to fully seal no matter what I did. Slight movements and changes would vary the levels but in practice, I noticed frequency response did not substantially change. Still, be on notice that my confidence in measurements are not super high (although EQ settings verified that they were good enough for that purpose).

Neumann NDH20 Measurements
Let's start with our usual frequency response:

View attachment 158335

I was quite surprised by this response. Given Neumann's heritage for neutrality in speakers, I expected a flat and bass shy response. Instead we have plenty of bass but then a suck out in the 1 to 3 kHz. We also have a deep cancellation around 2.6 kHz. I am not used to seeing such at such a low frequency. Relative response therefore shows somewhat a "V" response:

View attachment 158336

Distortion is very good considering that we don't need to boost the bass where it rises:

View attachment 158337

View attachment 158338

Something is definitely not right around 2.5 to 3 kHz though. We see the same in Group Delay:

View attachment 158339

It seems like a strong resonance of sorts out of phase with the response of the driver.

Impedance is middle of the road and mostly fixed:

View attachment 158340

Sensitivity is decent:

View attachment 158341

Headphone Listening Tests
First impression is not bad. You can hear the emphasis in bass and also some accentuation of highs. It is not until you dial in some EQ that you realize the imbalance:

View attachment 158342

I had to play a lot with these dials as the sound wound up being too bright after my initial correction. I was mostly happy with it but not quite there. It is possible some would prefer the heavier bass response.

Sub-bass response as you would expect is excellent.

Conclusions
This was a surprising outcome from Neumann. I expected a more neutral headphone but instead got a bass heavy one. Even though I am a fan of bass, it needs to be balanced relative to the rest of the response. I find that when the 1 to 3 kHz is sucked out, the sound becomes closed in which is a death sentence in my book for headphones as they already bad in that regard.

Equalization helps a lot but needs more refinement to get to a good place.

I can't recommend the Neumann NDH20 without EQ. With EQ, it barely gets there.

----------
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Hi,

Here are some thoughts about the EQ.

Notes about the EQ design:
  • The average L/R is used to calculate the score.
  • The resolution is 12 points per octave interpolated from the raw data (provided by @amirm)
  • A Genetic Algorithm is used to optimize the EQ.
  • The EQ Score is designed to MAXIMIZE the Score WHILE fitting the Harman target curve with a fixed complexity.
    This will avoid weird results if one only optimizes for the Score.
    It will probably flatten the Error regression doing so, the tonal balance should be more neutral.
  • The EQs are starting point and may require tuning (certainly at LF).
  • The range around and above 10kHz is usually not EQed unless smooth enough to do so.
  • I am using PEQ (PK) as from my experience the definition is more consistent across different DSP/platform implementations than shelves.
  • With some HP/amp combo the boosts and preamp gain need to be carefully considered to avoid issues
  • Not all units of the same products are made equal. The EQ is based on the measurements of a single unit.
  • YMMV with regards to the very unit you are trying this EQ on.
Decent L/R match.

I have generated one EQ, the APO config file is attached.

Score no EQ: 36.1
Score Armirm: 43.4
Score with EQ: 88.5

Code:
Neumann NDH20 APO EQ Full Flat@HF 96000Hz
October112021-135129

Preamp: -9.3 dB

Filter 1: ON PK Fc 95.44 Hz Gain 4.26 dB Q 2.08
Filter 2: ON PK Fc 108.67 Hz Gain -5.62 dB Q 0.57
Filter 3: ON PK Fc 2256.34 Hz Gain 10.00 dB Q 1.07
Filter 4: ON PK Fc 3555.50 Hz Gain -6.95 dB Q 3.15
Filter 5: ON PK Fc 7396.15 Hz Gain 6.27 dB Q 3.96
Filter 6: ON PK Fc 8331.02 Hz Gain -7.18 dB Q 6.00

Neumann NDH20 Dashboard.png



Edit:
For those who think more is better:
Score no EQ: 36.1
Score with Score EQ: 88.5
Score with Full EQ: 91.8

Code:
Neumann NDH20 APO EQ Full Flat@HF 96000Hz
October112021-142215

Preamp: -9.4 dB

Filter 1: ON PK Fc 96.19 Hz Gain 4.26 dB Q 2.08
Filter 2: ON PK Fc 111.67 Hz Gain -5.62 dB Q 0.56
Filter 3: ON PK Fc 450.51 Hz Gain 0.91 dB Q 2.57
Filter 4: ON PK Fc 2249.34 Hz Gain 10.00 dB Q 1.08
Filter 5: ON PK Fc 3557.50 Hz Gain -7.37 dB Q 3.07
Filter 6: ON PK Fc 5787.60 Hz Gain -4.95 dB Q 3.15
Filter 7: ON PK Fc 7412.15 Hz Gain 9.47 dB Q 1.70
Filter 8: ON PK Fc 8356.46 Hz Gain -12.10 dB Q 5.98
Neumann NDH20 APO EQ Full Flat@HF 96000Hz.png


Same EQs but with modified Harman curve (within preference +3dB@LF & -1.5dB@HF).
Score no EQ: 56.0
Score Armirm: 64.3
Score with EQ: 80.4
Neumann NDH20 APO EQ Full +3dB@LF & -1.5dB@HF 96000Hz.png
 

Attachments

  • Neumann NDH20 APO EQ Full Flat@HF 96000Hz.txt
    483 bytes · Views: 65
  • Neumann NDH20 APO EQ Score Flat@HF 96000Hz.txt
    382 bytes · Views: 82
Last edited:

solderdude

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@solderdude Can you please comment on the cancellation? I have seen a similar thing in your measurements, even though it might be unrelated in this case.
Yes, can be cancellation.
I see this often and sometimes moving the headphone a 1 or 2 mm can make it much less deep or even disappear.
Amir (just like me) does not use smoothing.
Most measurebators do apply some smoothing.
smoothing removes dips and peaks. These do say something but is not easy to translate into perceived sound.
An interesting plot that should be accompanied when one sees sharp nulls is the GD and CSD can also be handy.
In some cases you see a sharp dip but on the CSD you just see that there is a little delay at that frequency.
So the level is not low, merely slightly delayed.

Below the DT1990 FR response. Look at the sharp dip at 4.7kHz which = -20dB

dt1990-120-ohm.png


Now look at the CSD (same measurement) one can see the dip is not as deep after approx 0.4ms

csd-120-analyt.png


so it can also be a delay thingy.

Similar thing with the TYGR but at a different frequency (7.5kHz):

fr-tygr-300.png


and CSD:

csd-tygr.png



and GD:

gd-tygr.png



and phase:

phase-tygr.png


Here we can conclude a resonance that shows in FR as a dip but seems to be merely delayed.
 

abdo123

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I wonder how audible super-narrow spikes in distortion (up to 104dB in this case) are?
*Since there is a dip in the FR probably not much if at all?

They probably are, they are so high that they represent speaker resonances at this point.
 

Robbo99999

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Amir's measurement of this headphone is quite similar to that done by Oratory, he's measured more than one unit though and averaged them:
I also did an EQ for this headphone about a year ago for an ASR member based on an earlier measurement that Oratory had done of this headphone, at which point he had obviously measured less units of this headphone (I don't know how many less), but anyway here's my EQ based on one of his earlier measurements & EqualiserAPO config file for this one attached at end of post. You can see the measurement has changed a bit over time since Oratory's earlier measurements of this headphone - the 3kHz peak has lessened over time as well as the 2kHz dip was lessened, so it seems there could be some unit to unit variation based around the size of the 3kHz peak & 2kHz dip as well as perhaps some changes in bass level.
Neumann NDH 20 Oratory Measurement, My EQ.jpg
 

Attachments

  • Neumann NDH20.txt
    327 bytes · Views: 88

Robbo99999

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Hi,

Here are some thoughts about the EQ.

Notes about the EQ design:
  • The average L/R is used to calculate the score.
  • The resolution is 12 points per octave interpolated from the raw data (provided by @amirm)
  • A Genetic Algorithm is used to optimize the EQ.
  • The EQ Score is designed to MAXIMIZE the Score WHILE fitting the Harman target curve with a fixed complexity.
    This will avoid weird results if one only optimizes for the Score.
    It will probably flatten the Error regression doing so, the tonal balance should be more neutral.
  • The EQs are starting point and may require tuning (certainly at LF).
  • The range around and above 10kHz is usually not EQed unless smooth enough to do so.
  • I am using PEQ (PK) as from my experience the definition is more consistent across different DSP/platform implementations than shelves.
  • With some HP/amp combo the boosts and preamp gain need to be carefully considered to avoid issues
  • Not all units of the same products are made equal. The EQ is based on the measurements of a single unit.
  • YMMV with regards to the very unit you are trying this EQ on.
Decent L/R match.

I have generated one EQ, the APO config file is attached.

Score no EQ: 36.1
Score Armirm: 43.4
Score with EQ: 88.5

Code:
Neumann NDH20 APO EQ Full Flat@HF 96000Hz
October112021-135129

Preamp: -9.3 dB

Filter 1: ON PK Fc 95.44 Hz Gain 4.26 dB Q 2.08
Filter 2: ON PK Fc 108.67 Hz Gain -5.62 dB Q 0.57
Filter 3: ON PK Fc 2256.34 Hz Gain 10.00 dB Q 1.07
Filter 4: ON PK Fc 3555.50 Hz Gain -6.95 dB Q 3.15
Filter 5: ON PK Fc 7396.15 Hz Gain 6.27 dB Q 3.96
Filter 6: ON PK Fc 8331.02 Hz Gain -7.18 dB Q 6.00

View attachment 158378


Edit:
For those who think more is better:
Score no EQ: 36.1
Score with Score EQ: 88.5
Score with Full EQ: 91.8

Code:
Neumann NDH20 APO EQ Full Flat@HF 96000Hz
October112021-142215

Preamp: -9.4 dB

Filter 1: ON PK Fc 96.19 Hz Gain 4.26 dB Q 2.08
Filter 2: ON PK Fc 111.67 Hz Gain -5.62 dB Q 0.56
Filter 3: ON PK Fc 450.51 Hz Gain 0.91 dB Q 2.57
Filter 4: ON PK Fc 2249.34 Hz Gain 10.00 dB Q 1.08
Filter 5: ON PK Fc 3557.50 Hz Gain -7.37 dB Q 3.07
Filter 6: ON PK Fc 5787.60 Hz Gain -4.95 dB Q 3.15
Filter 7: ON PK Fc 7412.15 Hz Gain 9.47 dB Q 1.70
Filter 8: ON PK Fc 8356.46 Hz Gain -12.10 dB Q 5.98
View attachment 158387

Same EQs but with modified Harman curve (within preference +3dB@LF & -1.5dB@HF).
Score no EQ: 56.0
Score Armirm: 64.3
Score with EQ: 80.4
View attachment 158380
Nice EQ, although personally I would have decided to use a somewhat lower Q / broader filter on the 8300Hz peak, as this would increase the chances of that peak being targeted when different individuals wear the headphone, I would have allowed the extra width of the filter to "blend in" with the natural measured dip at 10kHz. I used a Q of 3.5 on that peak whereas you used a narrower Q of 6.
 

solderdude

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that distortion peak just surprises me, ehm

Don't worry about the generated distortion number at 3kHz (it clearly has a resonance there) at 114dB SPL.
The moment you reach 114dB SPL at 3kHz, in music, you already have thrown the headphone a few meters away scared shitlless or have hit the mute button in record time.
You really can't hear that narrow a peak anyway if it were real.
The 114dB SPL measurement is only of value till a few hundred Hz.
It performs fine at those frequencies for such a small driver.
At 94dB SPL distortion at 3kHz is good enough not to be audible.
 
Last edited:

vkvedam

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Bummer! Someone please send in the Austrian Audio HI-X55 please :)
 

MikeJ

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If there's anything I've learned on this forum it's that "studio pros" are just as poor at judging what makes a good headphone/loudspeaker as the average audiophile is
What I've learned from this forum is that there's group of followers who take everything for granted on what is posted here, without even questioning themselves and performing their own individual research. Anyway, I'm still grateful for ASR, even if I sometimes disagree ;)
 

MikeJ

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Don't worry about the generated distortion number at 3kHz (it clearly has a resonance there) at 114dB SPL.
The moment you reach 114dB SPL at 3kHz, in music, you already have thrown the headphone a few meters away scared shitlless or have hit the mute button in record time.
You really can't hear that narrow a peak anyway if it were real.
The 114dB SPL measurement is only of value till a few hundred Hz.
It performs fine at those frequencies for such a small driver.
At 94dB SPL distortion at 3kHz is good enough not to be audible.
Yeah I value my ears so I don't listen above 85dB/SPL where it's getting uncomfortable for longer listening sessions.
 

xaviescacs

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What I've learned from this forum is that there's group of followers who take everything for granted on what is posted here, without even questioning themselves and performing their own individual research. Anyway, I'm still grateful for ASR, even if I sometimes disagree ;)
"You don't need to follow me, you don't need to follow anybody, you've got to think for yourselves, you're all individuals"
 

nyxnyxnyx

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This is my most used headphones in the last 2 years or so and I own quite a few, so I hope I have some credibility when I say this pair of headphones is a bit overpriced when it comes to sound quality only.

Amir's subjective listening opinion is similar to what I felt. Elevated bass (on the headfi thread we dragged this debate for like 5 pages), sounds clean, clear and distinctive enough from my previous headphones (hd600/650,r70x etc...), and in a good way too. I don't think it's uncomfortably bright even with or without EQ but I might have a different tolerance. It sounds good enough for me w/wo EQ but if stock sound quality is the only factor I consider, I won't pay the full $500 for it.

The build quality is really neat though, way sturdier than many other "audiophile" headphones I've had and touched. And if you can keep the headphones in good condition it's quite a looker, it also isolates sound quite great whether with stock pads or OEM ones, so all things considered I think it's pretty alright, its just more expensive than what it should be.


Always had a hunch that it wouldn't measure well but now you have confirmed my doubts. I hope they can make a revision but with their shortcomings improved :).
 

heflys20

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If there's anything I've learned on this forum it's that "studio pros" are just as poor at judging what makes a good headphone/loudspeaker as the average audiophile is
Nearly every pro audio manufacturer claims their products are the most "accurate" and "neutral". You'd think they'd want to provide measurements to corroborate such claims. Funny how few do, but people run with it.
 
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