Planar on a Budget

Hifiman make exceptional open back Planar headphones ( though their closed backs so far have been disappointing ) but can we really expect that planar experience for little over $100. he400se-overview.jpeg

What is the planar ’experience'

If you are new to headphones you might wonder why would I want a planar magnetic headphone instead of a traditional dynamic driver headphones. Well Planar’s typically provide better detail retrieval, a much more even frequency response resulting in a much more balanced sound. They also typically have much better bass than open back dynamic drivers and have lower distortion meaning playing music with a larger dynamic range without affecting the fidelity, but the downside is typically that you need more power (so are less portable) and with an open back headphones in general, you will hear the outside world and other people near you will hear your music, so not the best headphone for commuting or a shared workspace, but when listening at home or in a private office space they provide an excellent audio experience.

Read on to find out if the base model in Hifiman lineup can live up to reputation that their more expensive planars deliver …



Note: Shout out to Mark @ hifiman for supplying these headphones for the purposes of this review.

In my headphone journey, I somehow missed out initially on the Hifiman HE400SE - when looking at headphones at this price point I went with closed back AKG and Sennheiser dynamic driver headphones. When I did go for an open back AKG K702 I was disappointed with the bass and the lack of balance which caused some of sibiliance issues with the treble. I simply didn’t believe I could get a decent open back planar experience on a budget, when I eventually did buy a planar with Hifiman Edition XS I was completely blown away. But the Edition XS made me curious about other Planar’s such is the headphone hobby. When some friends were asking for advise on what to get on a budget I became curious about the HE400SE, so I was very thankful with I got a HE400SE to review.

Packaging and unboxing

The package includes the headphones, a dual-sided high-performance 3.5mm cable, and a 6.3mm adapter. he400se-packaging.jpeg

Similar to the packaging in other Hifiman headphones, the protective construction clever doubles as a headphone stand, though not a particular high quality one. But I do like this clever re-use of the packaging: IMG_9152 Medium.jpeg

Build Quality

The HE400SE has a solid construction that exceeds expectations for its price range. Its combination of metal and plastic components, comfortable padding, and sturdy connectors contribute to a build quality that is both reliable and comfortable for extended use.

The supplied cable is also a much better quality than the one that shipped with the original HE400.

Comfort and Fit

The Hifiman HE400SE excels in providing a comfortable listening experience. I found that I could wear these all day without it feeling heavy, unlike say the larger heavier egg cup shaped Hifiman, like the Edition XS.

Both the headband and earcups are designed with the user’s comfort in mind, making these headphones a great choice for those who value comfort as much as sound quality.

Let’s get into the detail:

Material & Padding:

The headband of the HE400SE is a blend of functionality and comfort. It is padded adequately, possibly with memory foam, and wrapped in a soft, durable material that rests comfortably on the head. This design choice not only ensures comfort during prolonged usage but also promises durability.


Adjustability is a strong suit of this headband. IMG_9153 Medium.jpeg It easily accommodates various head sizes, maintaining its position reliably. This feature is particularly appreciated during extended listening sessions, as it eliminates the need for constant readjustment.

Weight Distribution:

The ergonomic design of the headband distributes the weight of the headphones evenly across the head. This distribution minimizes pressure points, making the HE400SE suitable for long listening hours without discomfort.

Clamping Force:

The clamping force is well-balanced – firm enough to secure the headphones in place without exerting excessive pressure on the ears or the sides of the head. This balance is crucial for comfort, especially for users who are sensitive to pressure.


The earcups are generously sized, fitting comfortably around the ears. This design choice not only enhances comfort but also adds to the overall sound experience, providing a sense of spaciousness while obviously not as good as the egg shaped design, IMG_9156 Medium.jpeg

I did find it a perfect size for my large ears unlike say the new FiiO FT5 which has a similar circular design but the internal diameter was smaller so just that bit smaller and less comfortable. Comparison EarCups.jpeg

Shape and Depth:

The earcups have a thoughtful design, with an circular shape and adequate depth, preventing the ears from touching the drivers – a common issue with shallower cups. This depth enhances the comfort significantly.


Hifiman has used plush cushioning in the earcups, likely a high-grade memory foam, which molds to the shape of the user’s ears. IMG_9155 Medium.jpeg The outer material, possibly a soft velour or leatherette, adds to the luxurious feel and comfort.


The material of the earcups also aids in breathability, reducing heat and sweat build-up during long sessions. This feature is essential for maintaining comfort over time.

Sound Isolation: i

For an open back headphone the design of the earcups provides some sound isolation, but like all open backs its designed to blend you music with your surroundings. This not only enhances the listening experience but also adds to the comfort by minimizing external distractions.

Sound quality

The Hifiman HE400SE not only impresses with its comfort but also stands out with its remarkable sound quality at this price point. This section explores the nuances of its bass, midrange, treble, soundstage, and imaging, underpinned by some song references that highlight these characteristics.



The HE400SE produces a bass that is both deep and articulate. It’s not overly boosted but offers a natural and balanced low-end presence. The bass is tight and controlled, avoiding any muddiness or bloating. However, it may not satisfy those seeking deep or impactful bass, especially in genres like hard rock or electronic music. But a little bit of EQ can provide that boost for those genres of music.

Song Reference:

With Portishead’s songs like “Glory Box” or “Roads,” the bass elements maintain their distinct character, avoiding muddiness or blending with mid-range frequencies. With the classic “Billie Jean” by Michael Jackson. The iconic bassline in this track is rendered with precision and clarity on the HE400SE, demonstrating its ability to handle rhythmic and dynamic bass lines effectively.



The midrange on these headphones is detailed and clear, ensuring vocals and instruments are well-represented. There’s a sense of warmth and naturalness to the mids, making it pleasant for long listening sessions.

Song Reference:

“Someone Like You” by Adele. The emotive vocals in this song are beautifully articulated, showcasing the HE400SE’s ability to capture the nuances and warmth of human vocals.


The treble range is crisp and airy, without veering into harshness. It adds a delightful sparkle to the overall sound signature, enhancing the detail in high-frequency sounds. This emphasis on treble complements the soundstage, giving instruments and effects a distinctive sizzle and contributing to the overall tonality of the headphones

Song Reference:

“Vivaldi’s Four Seasons - Spring”. This classic piece, with its high-pitched violin notes, demonstrates the HE400SE’s ability to handle treble without any sibilance, preserving the finesse of classical instruments.

Soundstage and Imaging

While not as good as the Edition XS the soundstage of the HE400SE is notably expansive. Despite its modest pricing, the soundstage’s width and height create a layered, articulate, and immersive experience. This is particularly evident in complex musical arrangements where it achieves great separation between various elements, although it still relies on a somewhat closer image compared to other HiFiMAN models

Song Reference:

“Hotel California” by The Eagles, live version from “Hell Freezes Over”. The live ambiance, the placement of instruments, and the audience’s applause are portrayed with a remarkable sense of space and position, making it a great test for the HE400SE’s soundstage and imaging capabilities.

Audio quality Conclusion

The Hifiman HE400SE excels in delivering a balanced and detailed sound across the spectrum. Its ability to render bass with precision, articulate the midrange with clarity, and provide crisp treble, all while offering an expansive soundstage and accurate imaging, makes it a versatile choice for various music genres.

Specs and Measurements

Frequency Response 20Hz-20kHz
Impedance 32Ω
Sensitivity 91dB
Weight 385g

The most important specifications is the 91db here as that indicates that you will need a good bit of power to power the HE400SE, an Apple Dongle (especially the European variant) will not have enough power, but the HE400SE will work with more powerful dongles (e.g. a Qudelix 5K or a FiiO BTR dongle) but I would suggest a nice desktop headphone amplifer to really get the benefit of this headphone. I was listening to it with various headphone amplifiers, even a basic headphone amp like the FiiO K11 provided plenty of power, also my new Macbook Pro headphone jack worked well but it really sounded amazing with the new Schiit Midgard which has tons of power, so I would suggest a good headphone amplifier.


I usually present measurement to indicate that some EQ modifications might be necessarily (e.g. increase the bass or lower the treble) but in the case of the HE400SE I found the out of box tuning was excellent, not as quiet good as the next ’level’ up Hifiman models (the Sundara and the Edition XS) but effectively nothing to cause any concern, I listened to the HE400SE for hours without feeling I was missing anything or getting overlay fatiqued with the amount of treble, it really is a great sounding headphone at this price.

Frequency response

But For those interested here is the Frequency response compared to some other well known open back headphones (all of which are considering more expensive): FR A little bit of a dip between 1Khz and 2khz might be something that you could EQ and while the HE400SE has a typical planar Bass you can easily EQ that to your preference. Note: The Sennheiser HD 6XX (a legendary open back dynamic driver reference headphone has considerable worse bass).


Distortion with most planars is incredible low and the HE400SE is no exception. Here are some measurements from the AudioScienceReview: img.png The ‘green’ level above where the distortion is still only 2% is at ear shattering 114db your own listening level wiil be below 94db.


There is really nothing to EQ but you could add a bass shelf of a couple of db and possible raise that 1.9Khz dip a few DB.


One interesting aspect of the HE400SE is possible because it’s easy to lower the treble without EQ with some simple hacks. I didn’t find this necessarily but I guess some people like a little less treble and I am only referencing the hacks here for completeness. Effectively the ‘hacks’ are simply adjustments to the planar drivers which are easily accesssible once you take off an earcup: IMG_9154 Medium.jpeg

The simplest hack was suggested by DMS in this youtube video (a bit of tape over part of the planar driver will dampen the treble slightly):


At this price point ( $100-$150), there simply isn’t an viable alternative planar, but at the ($300-$500) level Hifiman have 2 alternatives the Sundara (also with round earpads) and the Edition XS (with iconic Egg shaped earpads), there is also the new Moondrop Para at about the $300.


I gave the HE400SE a pragmatic rating of 5 the same as the Hifiman Edition XS, in their price categories they are both amazing headphones and are the best choices for those wanting that planar sound. The Edition XS is better but at about 1/4 of the price the HE400SE is a superb pragmatic headphone.


Overall, the HE400SE is an excellent choice for those new to planar headphones and looking for a high-quality yet affordable option. Its strengths include a deep soundstage, detailed midrange, airy highs and comfort. While its sound signature may be pickier and more relaxed, it excels in depth and detail retrieval, making it the definitive planar headphone in the sub $200 price range. I have already recommended it a few times as good christmas presents as whoever receives will not be disappointed.