
THE PLUS:
- Above average technical ability, great imaging, well-rounded stage, neutral but still very musical
- Build quality was definitely improved if we compare these to older Hifiman releases
- Pretty efficient, although you won’t be able to fully enjoy them without an amplifier
- You get much more than you pay for
THE SO-SO:
- Sub-bass extension could be better
- Cable is horrible: it’s very stiff and has a very annoying microphonic effect
- Pretty heavy on the head
Tonality: 7/10
Technicalities: 7.5/10
Construction-Design: 7/10
Sound-Value: 8/10
PS: No BS Audiophiles is now with a S! Thanks to the new part time reviewer NICHOLAS ZAZA from AUDIO MONKEYS that join this audio blog for the sake of Diversity of No BS audio impressions.
Introduction
After sending a pm to Mark from Hifiman regarding the opportunity to make a review of the HE400i 2020, he accepted the proposal and prepared the shipping of the headphones.
I got the package delivered some weeks after those messages and I was surprised to see that there was a pair of HE400se instead of the HE400i 2020 in the box.
I was confused at first but then I started searching for informations regarding the HE400se and found out these replace the HE400i 2020 for the international market. Nothing to worry abou them, Hifiman usually know what they do.
Now, it’s time to see out how good can an affordable planar be!
Technical Specifications
- Type → Planar headphones with “Stealth Magnet Design”
- Sensitivity → 91 dB
- Impedance → 25 Ohm
- Frequency Response → 20 Hz – 20000 Hz
- Cable → 1,5m – detachable, no mic or remote
- Connector type → straight gold plated 3.5mm jack connector
- Weight: 390 g
Packaging
The box only contains:
- The HE400se
- The detachable cable
I have to say the overall package is a bit underwhelming, but I won’t be so hard in this case as these are very affordable if you think they have the same driver technology used for higher priced Hifiman headphones.

Design and Build Quality
The HE400SE are surprisingly solid and well built. Their design is clean and even if they’re not super fancy, there’s definitely some beauty to them.
The earcups are made of plastic but they do not look cheap: if I have to be honest, the first time I got my hands on the HE400SE I thought the earcups were built from metal, but then after touching the whole frame I discovered that the side joints that connect the headband to the earcups are made of metal while the latter are not.
The black grill behind the earcups reveals the magnets inside and while many are replacing it to mount a grill with larger holes (from older hifiman headphones) I like it just as it is.
Every earcup has a 3.5mm jack hole as the cable needs to be plugged in both cups (double-ended cable).
Hifiman have chosen to use the single headband instead of the old headband system used for the previous HE400i or HE400S for example, and this really seems like a more durable solution.
The velour pads are comfortable and are surrounded by memory foam. I cannot speak about their durability as I have the product since some weeks and this is not enough time (and use) for making statements about their longevity.
The overall impression is pretty good, they’re solid and there are no “creaks” while extending the cups or stressing the headband.




Cable
If there’s something that we can really complain about while looking at the HE400SE, it is certainly the cable. It’s really something I wouldn’t have included as stock cable: it’s very stiff and almost impossible to wind as its stiffness just makes everything useless. Plus, it has some microphonics that is pretty annoying.
I think Hifiman could include a softer cable and simpler cable: a cheap rubber cable could have been better (users that are more concerned about the cable would have swapped it in any case).

Comfort and Isolation
Even though the single headband seems like a more durable solution, the old auto-adjustable headband was way more comfortable.
The headphones are not really lightweight and the single fixed headband concentrates all the weight in a single point, thus becoming uncomfortable after some time.
Your mileage may vary, but in my case, I think these could have been a tad more comfortable to wear considering how much I like listening to music with these.
When it comes to isolation, there’s nothing to say: they are open-back headphones so you can easily draw your conclusions by yourself.
Sound
How do these sound?
This is the real reason you’re reading this review (I guess).
[Personal preference: I listen to almost every genre, even though my main preference goes to EDM subgenres. I always like a bit more energy on the bass and on the highs, leading to a personal preference for Y-shaped sound signatures, but if I have to choose, I’d prefer having many different IEMs with various signatures, in order to choose a particular one of them when I want to listen to a specific genre. I love switching between my IEMs so it’s even better if they’re very different from each others.]
TEST GEAR
- DAC: Topping E30
- AMP: Topping L30
- Mobile phones: Poco F2 Pro, Samsung Galaxy S7 Edge
- Portable DAPs: Benjie S8/AGPTEK M30B
- Other sources: Presonus AudioBox iONE, Cooler Master GS750
HOW DO THEY SOUND?
Do they need an amp?
Yes.
They’re promoted like the perfect mobile headphones to pair with tables, smartphones, but honestly… they are not.
The average volume you’ll get from that kind of source is pretty low and performance will suffer: it’s just not worth listening through a weak source.
Sound signature
The HE400SE have a fairly neutral signature with slightly elevated treble and forward midrange.
Lows: low end is always the part of the spectrum that suffers most when speaking about open back cans. However, we have to take into account that planar drivers are totally different and can satisfy most of the listeners that search for good bass performance.
The sub-bass on the HE400SE isn’t really impressive, lower notes are not going to be hit and many of you will probably like using some EQ.
Bass is tight, it has good punch and impact and it is precise; it does not overextend into the midrange and it’s reproduced accurately but lacks a tad of weight and body (although it still sounds very good).
I have to say I’m surprised considering I was not expecting such a good bass, even though I sometimes need to apply some EQ in order to push out some more sub-bass.
Mids: if there’s an area of the overall frequency range that really shines, then there’s no doubt it’s the midrange.
Instruments are forward, detailed, accurate and when more of them are playing simultaneously the HE400SE can keep up without compromising any of them.
Vocals are great, moreover female ones: the singer is right next to your ear with lots of intimacy and delicacy, but also a lot of energy. Male voices could slightly benefit from a deeper low-end but they’re definitely enjoyable, it’s just that I’m used to even warmer vocals and this is just about right (so when I think something’s missing, the truth is probably nothing’s out of its place).
Highs: lower treble is on point and it improves both clarity and dynamic; if we had a more prominent upper bass, this kind of tuning choice would have been crucial for the dynamics as treble is not tamed down but it is left balanced and smooth.
There is not trace of sibilance, at least to my ears (this statement is based on my own test playlist, but YMMV if you usually listen to tacks that didn’t get proper care during recording or mixing) and this is a BIG plus!
The upper treble has fairly good extension and there’s plenty of detail without necessarily exaggerating treble. Plus, this tuning leads to a spacious and airy sound that gains some more space in the various direction thanks to the treble.
Are they flat so? No.
They’re neutral, but they’re part of that “segment” of neutral products that tend to go for a little brighter approach.
I think this is a very good tuning for almost every kind of listening sessions (although I prefer warmer headphones at night for example).
But please… be sure to connect them to an amplifier!
Even though soundstage isn’t particularly big in terms of size, the HE400SE play in a well-rounded stage where width prevails over depth and height, and they image very well. In fact, they can really pride their themselves for their precision in pinpointing instruments, vocals and other sounds on the stage. Instrument separation is good and there’s no congestion even in busy passages.
I do not own any open back cans in this price range but I used to listen to some music with the HE400S (although I do not have them with me now).
The HE400S were definitely something surprising in their price range, despite some minor (but still something to point out) issues.
The signature is similar: the bass quantity is on the same level, the midrange is forward on both, and the treble has the same overall tuning. It’s safe to say the HE400SE extend a tad more in the low-end, with sub-bass digging slightly deeper than on the HE400S, which had less extension on the lower end).
From what I remember, the HE400SE are a bit more refined and smoother sounding than the HE400S in the lower treble region.
It seems like the new driver used in the HE400se is more “reactive” and faster, thus granting more agile passages in certain tracks.
In terms of driveability, the HE400SE should be more efficient, but I don’t have the HE400S with me to test this out.
But we have some other good news: the HE400SE improve two of the most criticized aspects of the HE400S (and HE400i): build quality and pads.
Build quality is now better, and while the HE400S were mostly made of plastic with the elastic headband, the HE400SE have metal earcups supports and have a single and thicker headband. In addition, HE400SE’s earpads are better and it seems like they’ll last longer (cannot know for now but this is my first impression, and considering this is a loaner unit I do not think I’ll have the chance to test them on the long run).
Speaking about the cable, I really don’t like the one shipped with the HE400SE, it’s very bad in my opinion, and even though the one shipped with the HE400S and HE400i was not great, it’s still better than this one.
Final Thoughts
Dear Hifiman, I’m so happy when you push these kind of products on the market.
The HE400SE sound very good, with above average technical ability for their price range and neutral signature that makes them perfect for listening to almost every kind of music (although fans of EDM and Hip-Hop should need some EQ to get a bit more oomph in the low-end).
Closing an eye on the very disappointing cable, I can definitely recommend these, but only if you plan to use them with an amplifier as you won’t be able to fully enjoy them otherwise.
Another thumb up for Hifiman!
———–
Disclaimer: the Hifiman HE400se were sent by Hifiman as a loaner unit. I do not know how long will I be able to keep these but for now it seems like I’ll have to return these to Hifiman in the future.
At the time of the review, the Hifiman HE400se were sold for about $149 on the official Hifiman website and for about €169 on Amazon.
Hi there! Thanks for the nice review on the 400se. I was about to pull the trigger on this pair, but the sub-bass comment kind of puts me off.
What open cans would you recommend for more low end oomph?
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I would highly recommend the SUNDARA
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