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Hifiman HE400i Review 2020 Revision (Headphone)

Remlab

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I believe a study on the actual effect of EQ on headphones vs predicted is due. It may be somewhat cumbersome, but a one time shot at it could at least answer some questions many have regarding this issue.
 

Chocomel

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I believe a study on the actual effect of EQ on headphones vs predicted is due. It may be somewhat cumbersome, but a one time shot at it could at least answer some questions many have regarding this issue.

You mean if the frequency response changes like the EQ graph indicates?
 

GaryH

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Was there a suspicion that they changed the headphones or drivers in some way?

They use the same pads (these ones), at least ostensibly. The improvement in distortion suggests differences in the drivers:

index.php


index.php
 

BostonJack

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Great review! I own a set of Drop 4xxi headphones that I enjoy (unequalized). My main use is when I am working outside my home, as I my laptop will easily drive these. Mainly for meetings and music while working (not exactly critical listening).

I'm excited to try EQ'ing mine and doing rough compares to my Drop HD 6XX headphones, which I love.

The 4xxi's have a certain clarity that I don't get tired of.
 

Remlab

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You mean if the frequency response changes like the EQ graph indicates?
Yes.
You mean if the frequency response changes like the EQ graph indicates?
Yes. After all, this site is about communicating with objective measurements, so simply reporting on subjective improvements without at least giving a clue about what's actually going on is a little bit mystifying. Since it would be cumbersome and time consuming for Amir to do it on every headphone, I think one article with actual measurements on the subject would probably suffice.
 

GaryH

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Great review! I own a set of Drop 4xxi headphones that I enjoy (unequalized). My main use is when I am working outside my home, as I my laptop will easily drive these. Mainly for meetings and music while working (not exactly critical listening).

I'm excited to try EQ'ing mine and doing rough compares to my Drop HD 6XX headphones, which I love.

The 4xxi's have a certain clarity that I don't get tired of.

Looks like the HE4XX is generally the best of the HE400 series (highest Harman predicted preference rating among them of 89/100), with a good balance of decent bass extension for an open-back and on average closest to the target in the upper mids / treble, especially between around 1 and 5 kHz where our hearing is most sensitive:

Harman 2018-Hifiman HE4XX-Hifiman HE400i (2016)-Hifiman HE400i (2020)-Hifiman HE400se-1.png


As for EQ, try Oratory's here.
 
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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.

Good L/R match.

I have generated two EQs, the APO config files are attached.

Score no EQ: 85.5
Score Armirm: 96.8
Score with EQ: 106.6
Score with EQ Full: 108.3

Code:
Hifiman HE400i APO EQ [email protected] 96000Hz
August172021-093855

Preamp: -5.6 dB

Filter 1: ON PK Fc 32.72 Hz Gain 5.58 dB Q 0.70
Filter 2: ON PK Fc 197.74 Hz Gain -1.81 dB Q 1.29
Filter 3: ON PK Fc 372.89 Hz Gain -2.05 dB Q 1.88
Filter 4: ON PK Fc 961.56 Hz Gain -2.28 dB Q 3.23
Filter 5: ON PK Fc 2099.38 Hz Gain 4.69 dB Q 2.78
Filter 6: ON PK Fc 4973.43 Hz Gain 3.74 dB Q 5.03
Filter 7: ON PK Fc 8649.46 Hz Gain -7.68 dB Q 7.14

View attachment 147951

For those you still think it could be even better (I am not too sure)

Code:
Hifiman HE400i APO EQ Full [email protected] 96000Hz
August172021-095851

Preamp: -9.6 dB

Filter 1: ON PK Fc 13.90 Hz Gain 6.85 dB Q 0.65
Filter 2: ON PK Fc 27.51 Hz Gain 4.80 dB Q 0.66
Filter 3: ON PK Fc 200.55 Hz Gain -1.83 dB Q 1.29
Filter 4: ON PK Fc 401.66 Hz Gain -2.31 dB Q 1.64
Filter 5: ON PK Fc 557.52 Hz Gain 2.46 dB Q 5.35
Filter 6: ON PK Fc 955.81 Hz Gain -2.32 dB Q 3.53
Filter 7: ON PK Fc 2110.63 Hz Gain 4.67 dB Q 2.84
Filter 8: ON PK Fc 4984.70 Hz Gain 5.03 dB Q 7.47
Filter 9: ON PK Fc 8660.27 Hz Gain -7.93 dB Q 7.87

View attachment 147948
I've got the Hifiman HE4XX which is quite similar to this headphone, and this is the only headphone that for me benefits by boosting the bass all the way to the Harman Curve all the way down to 20Hz, which is exactly what you've done there in your second EQ.......so I recommend your second EQ to folks reading this. My other headphones don't seem to respond particularly well to boosting to Harman Curve bass all the way down to 20Hz, I normally roll off at 35Hz as it seems to increase overall clarity.....but like I say the HE4XX (and probably by extension the HE400i in this review) is the only headphone of mine that shows no ill effects on overall clarity by boosting to Harman bass levels down to 20Hz. I do like my HE4XX, it's probably the best headphone I have for bass (after EQ) although close run with my HD560s (& NAD HP50 when I can get it to sit right), and the soundstage is pretty good on the HE4XX, so likewise probably very similar to the HE400i reviewed here, as very similar design.
 
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GaryH

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I've got the Hifiman HE4XX which is quite similar to this headphone, and this is the only headphone that for me benefits by boosting the bass all the way to the Harman Curve all the way down to 20Hz, which is exactly what you've done there in your second EQ.......so I recommend your second EQ to folks reading this. My other headphones don't seem to respond particularly well to boosting to Harman Curve bass all the way down to 20Hz, I normally roll off at 35Hz as it seems to increase overall clarity.....but like I say the HE4XX (and probably by extension the HE400i in this review) is the only headphone of mine that shows no ill effects on overall clarity by boosting to Harman bass levels down to 20Hz.

Likely because the HE4XX's planar drivers have low distortion in the (sub)bass, compared to the majority of dynamic drivers which have higher distortion there.
 

FrantzM

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Well since you ask ... I'd like to see more amps, preamps, integrateds, AVRs, and (yet even more) speakers but more floorstanders, planars, and horns and maybe fewer studio monitors. Agree about DACs and headphone amps (obviously): I've had my fill.

OK, I acknowledge the logistic issues of getting such items to him for testing, (e.g. Avantgarde Trio XD's with a Basshorn XD).

header-trio.jpg
Not expecting much from those ... Lot of output that can be matched by a complement of subwoofers costing 1/10 ?
Or a jagged frequency response with directivity all over the board? for the "mains"

We'll (not) see...

Peace
 

phoenixsong

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Question to all: Are impulse response tests done at a particular frequency?
 

GaryH

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Question to all: Are impulse response tests done at a particular frequency?

By Fourier analysis an impulse comprises of all frequencies, in equal proportion. In fact that's precisely why it's chosen to measure frequency response.
 

Oddeeo

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What?!? Yet another headphone review? Surely we're getting close to an exhaustive survey of headphones.

For yet even still more headphone reviews, (currently 615), check out Rtings Headphone reviews, (no affiliation). Rtings has a different reviewing approach but it includes objective testing.

Let's give Amir a break by stopping sending him endless headphone for review. Personally I hate headphone listening and am a pains to avoid it -- hands up people who feel the same way.

You are in the minority here. His headphone reviews are by far my favorite, and I heavily await the Arya review with baited breath (as they are my main headphones).
 

Chrisxxx26

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Gorganzola said:
What?!? Yet another headphone review? Surely we're getting close to an exhaustive survey of headphones.

I hope for a lot of more headphone reviews to come. Because Amirs approach is fresh and insightful. Also, I was and still I am a sceptic about the whole "everything is better with eq" thing, the first time that I really find things improved was with Armirs recommendation for the Bose QC 35. I am not 100% sure I did it right, but what I have attached form Neutron player really improved the headphone sq.

Interestingly when I tried out the autoeq feature with the oratory or crincale settings for my HD560S it sounded worse than without eq. What it did - to MY ears - was it “veiled” the sound it didn’t feel so direct and “live” like without eq.

Highly subjective of course and just my 50c. The only other hp I tried with Amirs settings are my 1000xm4. Here it sounded different but not better.
 

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amirm

amirm

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dorirod

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I really find things improved was with Armirs recommendation for the Bose QC 35. I am not 100% sure I did it right, but what I have attached form Neutron player really improved the headphone
You don't have the right EQ that Amir provided. It should look like this:
 

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