Hifiman HE400i Review (planar headphone)

[Bob-23]

As is, the headphone has a rather "open" sound but nowhere near the spatial effects that the Sennheiser HD800S had. The sound is compressed around a grouping close to my ears.

Thanks, Amir, for testing headphones now. We headphone lovers have been waiting for that! And, of course, we want to know if headphones are eq'able to satisfying results. (Nearly) no headphone is perfect.

Rtings also has a somehow critical take on HE400i's soundstage, and that may be the difference to K702's famous soundstage:
"However, the notch around the 10KHz region is not very accurate or deep, which suggests a soundstage that is relatively natural and large but located inside the listener's head."

Maybe, someone could elaborate on that (in)famous 10k-notch - which is supposed to determine if the soundstage is located inside or outside of the listener's head?

The 10k-notch you measure seems to be 'more accurate' than Rtings'?

"What it is: The depth of the "10kHz notch" of the headphone's PRTF, which is caused by phase cancellations at the concha. This quality is monaural and can be perceived even with one ear. This test does not apply to in-ears and earbuds, due to the lack of pinna interaction. " (Rtings)

EDIT: with regard to rtings measurements: the notch of the HE400i seems to be a little bit deeper than the one of the K702, but the notch on the He400i is 'less accurate' than the one on the K702. Taken seriously, not only the depth but also the form ('accuracy') of the notch could be decisive?

 

[JohnYang1997]

There's one way to find out whether the notches are real. Just use sine generator website. And manually sweep across the 5khz+ region. Planars do get some sort of cancellation but you always should try for yourself.
https://www.szynalski.com/tone-generator/
Reduce the volume before playing the tone

 

[Doodski]

Online tone generator.

 

[solderdude]

Amir measured HE400i before on the more expensive 5128:

below the same headphone measured on the Gras 45CA..

 

[JohnYang1997]

Amir measured HE400i before on the more expensive 5128:

View attachment 100221

below the same headphone measured on the Gras 45CA..

View attachment 100222

That's how we know we are fucked...

 

[Helicopter]

How many people actually EQ I wonder. We talk a lot about the advantages, but if you are not using a player that plays nice or includes it, then is is often a PITA technical problem.

I really need to get some hardware based PEQ like Qudilex K5, MiniDSP, and Behringer DEQ2496, because I almost exclusively listen to vinyl and Amazon HD, rarely on a computer, and I have not had much luck with free PC software anyway, including the Focusrite program, the Audeze one, and REW.

I really want something from Schiit, Topping, Loxjie, SMSL. I think it is time to start incorporatimg it. With headphones, I mostly listen to digital music, so I would be in good shape with PEQ in the DAC, but it would be a nice option on an amp.

 

[pavuol]

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.

Yep, was thinking about the same. How does distortion correlate to EQ-ing. Do have specific headphones "problematic" frequency regions that reply worse to EQ changes than others? Do lower frequencies distort worse post-EQ than higher ones? How do different driver technologies respond to EQ distortionwise (dynamic, planar, e-stats..)? Are pricier models of the same driver technology (maybe same mfg as well) better?
Would make for a nice separate article..

 

[Matias]

How many people actually EQ I wonder. We talk a lot about the advantages, but if you are not using a player that plays nice or includes it, then is is often a PITA technical problem.

I really need to get some hardware based PEQ like Qudilex K5, MiniDSP, and Behringer DEQ2496, because I almost exclusively listen to vinyl and Amazon HD, rarely on a computer, and I have not had much luck with free PC software anyway, including the Focusrite program, the Audeze one, and REW.

I really want something from Schiit, Topping, Loxjie, SMSL. I think it is time to start incorporatimg it. With headphones, I mostly listen to digital music, so I would be in good shape with PEQ in the DAC, but it would be a nice option on an amp.

RME ADI-2 DAC fs has 5 band PEQ built in so that you can set it for your headphone(s) and use whatever source you wish.

 

[pavuol]

Just to point out one of the "non-audio" factors specific to headphones. In this manner planars seem not so "open" as the dynamic headphones, of course earcup padding material comes to play as well.
Courtesy of Rtings - left - Sennheiser HD800s (in fact the best in their "breathability" chart - open-back+over ear filter),
right - Hifiman he400i (in lower tier):

 

[bobbooo]

Hmmm. You post this in the 800S thread:

Unlike what you post jut now, this one shows the clear problems in the mid-range and correlated well with my measurements:

Both show similar distortion in 300 to 400 Hz range and again around 1 to 2 kHz. Yet you said distortion was "nice and low?" Regardless, the correlation is good enough between my measurements and Tyll are good enough that I say we are looking at a real issue here.

I would caution against putting any trust in distortion measurements from Tyll. This wasn't his forte and there is no evidence that his measurements are correct.

Hmm. Can't have it both ways In the context of the HD800S's 35% post-EQ distortion (which is what really matters since both need EQ), yes, the HE4XX's distortion is nice and low. Jude of Head-Fi's measurements that I posted above were with a GRAS, so more comparable to yours. He also uses a proper isolation chamber:

To help improve the quality of the measurements, we wanted to maximize environmental isolation. Though we obviously do not have the space (not to mention the budget) to build a full walk-in anechoic chamber, we still wanted to achieve as much acoustic and vibration isolation as reasonably possible. Skylar Gray (formerly of AudioQuest, now with Definitive Technology) recommended we contact Herzan. We worked with Herzan to carefully spec out a custom-built acoustic and vibration isolation enclosure. Our Herzan enclosure has thick walls, made with 11 variable density layers of sound-damping material, and the interior of the enclosure is lined with acoustic sound absorption foam. This enclosure is (by design) fairly massive, weighing around 1200 pounds -- the more mass there is, the more energy it takes to excite the system. The enclosure has two cable ports, both covered with solid machined metal screw-down blocks that are damped, and also have soft gaskets that allow full sealing around the cables. (See photo below.)

The headphone measurement manikin or fixture being used at the time is placed on a Herzan Onyx-6M vibration isolation table, to further help isolate the system from vibrations caused by foot traffic, HVAC systems, vehicle traffic, etc. The Onyx-6M is essentially a steel tabletop supported by pneumatic isolators, and provides isolation beginning at 4.5 Hz.

(Above) Closed left-side cable port on the Herzan acoustic/vibration isolation enclosure.

Even with the Herzan enclosure, we still make sure to keep it as quiet as we can in the office while doing measurements. Both of the office HVAC systems are switched off when we measure. You'll frequently hear the tongue-in-cheek cry, "Measurement in 3...2...1...fire in the hole!" before we start a measurement, and everyone remains quiet until an all-clear is given.

Oh and Rtings' (who use an isolation box) measured the HE400i (left, no backplate) to have better distortion than the HD800S (right):

This puts the HE400i (no backplate) joint best of all the over-ear headphones they've measured in terms of distortion. Once again, any inferences from measurements of the HE400i (with backplate) to the no-backplate version are invalid, and stretching that even further to the HE4XX even moreso. So no, there is no evidence that there is a real issue with the latter two's distortion.

 

[Dro]

Someone post that the HE400i is one of the lowest distortion headphones out there. I sure hope not given the above performance!

Headphones are generally bad with distortion. Planar magnetic headphones tend to do better than dynamics, especially in bass. The 400i seems good, not great, for a planar. Here is my Ether 2 measured with a MiniDSP EARS, a good bit better than the 400i:

Notes:

• Spikes in distortion and frequency response at 4.7 and 7.4 kHz are an issue with the EARS. It has resonances there.
• Dip in frequency response and spike in distortion at 9.4 kHz might also be an issue with the setup. It being really narrow means it would be hard to confirm by ear. This is why Amir paid a lot more on his setup.
• Spike in distortion at 25 Hz is mains noise at 50 Hz picked up as 2nd harmonic at 25 Hz, 3rd harmonic at 16.67 Hz etc.
• 5th and higher harmonics are not material.

 

[rodtor]

RME ADI-2 DAC fs has 5 band PEQ built in so that you can set it for your headphone(s) and use whatever source you wish.

Yes, and the RME's bass and treble settings give you an additional two bands, as long as you have at least one each (and no more than two) of a low shelf and a high shelf in your settings. I recommend it if like Helicopter (and me) you would rather not always be using a computer.

 

[solderdude]

The whole distortion thing, especially in the bass area is grossly overestimated.
Distortion should be low in the 300Hz to 5kHz range.

I can play the HD800 (and HD800S which is here on loan) very loud with bass EQ'ed (not as severe as Harman and certainly not at louder levels) and bass sounds very clean and undistorted. And this is louder than I would normally ever listen (only for tests)
Bass is only lifted +5dB at 20Hz and +1dB at 100Hz. It also is not digital EQ so cannot advice any settings.

HD800S distortion:

Ignore 50, 100 Hz spikes.. This is done with a $ 0.60 microphone. That's why the 2nd harm doesn't go below 0.2%. This also is measured in a normal quiet room, no special measures taken.

The reason the 10kHz spike is not visible in Amirs plot is because his HATS has a very deep dip there, mine doesn't.
Removal of the peak makes the HD800(S) much less 'special' b.t.w.
Notice the treble extension of the HE400i compared to the HD800S. The angling of the HD800S may have something to do with this.

HE400i distortion (same conditions)

Both are low in distortion (90dB SPL). Granted at loud listening levels using music distortion in the lowest frequencies will rise. Most music doesn't have much LF below 32-40Hz.

 

[Sgt. Ear Ache]

Re: the weak headband, my experience as well with the HE4xx. Ended up modding the cup to have it take a completely different headband, works great now. Also applied a similar EQ, and it does make a world of difference

The headband issue was eventually resolved. There was a real bad batch of brittle plastic involved. They eventually released a re-enforced headband. When the brackets on mine cracked I contacted Hifiman and they replaced my headband with the improved one for free.

I think these cans sound fucking amazing btw. lol. I've always EQ'd them though...but I pretty much assume I'd want to EQ almost any pair of headphones I own. I just dialed up Oratory's recent updated profile and I like it very much.

 

[Ron Texas]

Does anyone around here know if Equalizer APO works with WASAPI Shared in Foobar2000, or do you have to use Direct Sound.

 

[Patrick1958]

Does anyone around here know if Equalizer APO works with WASAPI Shared in Foobar2000, or do you have to use Direct Sound.

Equalizer APO only works with direct sound.

 

[BogdanR]

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.

This is very much in line with my extensive listening experience with these headphones. Also in line with the asymmetrical earpads coming with it. Also “spatiality” changes and tends to be a bit better in a certain position. I guess the large size of the planar driver has something to do with it.

 

[Robbo99999]

Hmm. Can't have it both ways In the context of the HD800S's 35% post-EQ distortion (which is what really matters since both need EQ), yes, the HE4XX's distortion is nice and low. Jude of Head-Fi's measurements that I posted above were with a GRAS, so more comparable to yours. He also uses a proper isolation chamber:


Oh and Rtings' (who use an isolation box) measured the HE400i (left, no backplate) to have better distortion than the HD800S (right):

View attachment 100241

This puts the HE400i (no backplate) joint best of all the over-ear headphones they've measured in terms of distortion. Once again, any inferences from measurements of the HE400i (with backplate) to the no-backplate version are invalid, and stretching that even further to the HE4XX even moreso. So no, there is no evidence that there is a real issue with the latter two's distortion.

I think that's pretty compelling evidence that distortion is low on the HE400i no backplate version from RTings, and the proper isolation chamber of Head-Fi for the HE4XX measurement on a GRAS unit is also very compelling. I know Amir has explained why his distortion amounts are generally higher than other people's due to different graph scale and ability to remove noise from the equation which can mask distortion....but these guys with isolation chambers don't have the noise problem, and the graph scale is not an issue really to see what's going on....so I'm still surprised by the contrast in results. Although we're comparing Amir's potential backplate version of the 400i with the no backplate version from RTings and the HE4XX from HeadFi, so it's not quite apples to apples....however I think it does show good weight towards the idea that HE400i with no backplate and HE4XX are low distortion headphones.

The whole distortion thing, especially in the bass area is grossly overestimated.
Distortion should be low in the 300Hz to 5kHz range.

I can play the HD800 (and HD800S which is here on loan) very loud with bass EQ'ed (not as severe as Harman and certainly not at louder levels) and bass sounds very clean and undistorted. And this is louder than I would normally ever listen (only for tests)
Bass is only lifted +5dB at 20Hz and +1dB at 100Hz. It also is not digital EQ so cannot advice any settings.

HD800S distortion:

Ignore 50, 100 Hz spikes.. This is done with a $ 0.60 microphone. That's why the 2nd harm doesn't go below 0.2%. This also is measured in a normal quiet room, no special measures taken.

The reason the 10kHz spike is not visible in Amirs plot is because his HATS has a very deep dip there, mine doesn't.
Removal of the peak makes the HD800(S) much less 'special' b.t.w.
Notice the treble extension of the HE400i compared to the HD800S. The angling of the HD800S may have something to do with this.

HE400i distortion (same conditions)

Both are low in distortion (90dB SPL). Granted at loud listening levels using music distortion in the lowest frequencies will rise. Most music doesn't have much LF below 32-40Hz.

Do you know which version of the HE400i you measured? Backplate version or no backplate? 2016 or 2020?

Equalizer APO only works with direct sound.

I playback my music using ITunes with it set in Windows Audio Session mode rather than Direct Sound, and Equaliser APO works just fine with that. I think I remember reading that Windows Audio Session can be in exclusive mode or not, so I think that might be the deciding factor. (@Ron Texas this might be relevant to your question, I'm not sure).

 

[solderdude]

I measured one around 2017 and an older model.

The older model has 3dB lower treble peak and is slightly better around 500Hz.

 

[Robbo99999]

I measured one around 2017 and an older model.

The older model has 3dB lower treble peak and is slightly better around 500Hz.

I'll have to let bobbooo work out the likelihood of any of those being the backplate or non-backplate model, and I suppose you'd have to let us know which of those two headphones your distortion measurements come from if we wanted to draw any conclusions.