hifiman he400se review banner HIFIMAN HE400SE Open-back Planar Headphones Review

HIFIMAN HE400SE Open-back Planar Headphones Review

The HIFIMAN HE400SE is a product we’re focusing on here in our HIFIMAN HE400SE Open-back Planar Headphones review. We’ll discuss its features, performance, design, functions, and specifications. 

The HE400SE is an entry-level magnetic planar pair of headphones from HIFIMAN – a Chinese audio manufacturer. It’s known for creating headphones and audio players. But lately, the brand has gained popularity for its impressive and expansive range of magnetic planar headphones. 

The HE400SE is a brand new product of the company’s classic HE400 circumaural open-back magnetic planar headphones. It’s one of the cheapest models in the range and today’s audio market. 

This HIFIMAN HE400SE Open-back Planar Headphones review will see if it’s as good as its competition or better. And if it’s worth purchasing. Before everything else, we’ll check out its packaging and contents. 

HIFIMAN HE400SE Open-back Planar Headphones Packaging

When our headphones arrived for this HIFIMAN HE400SE Open-back Planar Headphones review, we saw and instantly loved its packaging. The box sports an all-dark theme combined with sleek silver/grey fonts giving off a premium aesthetic. 

hifiman he400se review1 HIFIMAN HE400SE Open-back Planar Headphones Review

The front of the package displays one side of the headphones, HIFIMAN’s branding, and the product’s name. Inside the box there was a headphone cable included.

hifiman he400se review4 HIFIMAN HE400SE Open-back Planar Headphones Review

HIFIMAN HE400SE Open-back Planar Headphones Review – Design and Functionality

These headphones sport big, over-the-head style, circumaural ear cups. The HE400SE uses the current HIFIMAN aesthetics for a redesigned headband and more articulating ear cups.

We also noticed the product’s headband while creating our HIFIMAN HE400SE Open-back Planar Headphones review. It’s something we won’t skip since it’s an essential element for comfort.

The headband sports a classic arching design instead of the older models’ suspension strap style. It’s a single piece that’s durable and wrapped in soft, comfortable, leather-like material.

hifiman he400se review2 HIFIMAN HE400SE Open-back Planar Headphones Review hifiman he400se review3 HIFIMAN HE400SE Open-back Planar Headphones Review hifiman he400se review5 HIFIMAN HE400SE Open-back Planar Headphones Review hifiman he400se review7 HIFIMAN HE400SE Open-back Planar Headphones Review hifiman he400se review6 HIFIMAN HE400SE Open-back Planar Headphones Review hifiman he400se review9 HIFIMAN HE400SE Open-back Planar Headphones Review hifiman he400se review8 HIFIMAN HE400SE Open-back Planar Headphones Review

The headband’s new style looks quite familiar and will likely become HIFIMAN’s regular piece. It’s the same as those on the company’s other models: from their Deva to the HER10. The latter is one of their top products, and the feature is now on the  HE400SE.

Its aluminium yoke sits inside the headband rather than attaching it to the exterior for easy adjustment. 

The company focused on making the ear cups less prone to vibrations by stiffening the design, making it more solid. Additionally, it improved the ear cups’ recessed 3.5mm connectors for better efficiency. 

The tips are positive, while the sleeves are negative. This conventional HIFIMAN pin setup allows you to utilise any HIFIMAN wire. Also, the configuration makes it easier to search for an efficient aftermarket cable. 

The HE400SE’s ear cups sport a side hinge design with the yoke linking on each side. This setup gives you a free 360-degree motion, and it also lets you angle it in either direction. Aside from that, the design effectively matches your head’s contours. 

These ear cups also have large foam earpads sporting a hybrid design. This part has a leather-like finish on the velour and edges inside. Additionally, these pads are replaceable and detachable. 

The pads look like Pali pads but with stiffer foam inside and slightly thicker. Its construction is like the Pali pads with a hybrid design and perforated faux leather inside. 

Aside from being angled, the pads are thicker in the back, resembling Pali pads. The difference between them is that the HE400SE is stiffer. Its cups have a standard 100mm size with HIFIMAN’s clip-on design for its pad mount. 

You’ll see the driver and magnet arrays inside the ear cups. Its whole design and build come wrapped in thin cloth with nothing between it and the ears. 

The ear cups’ other side has metal grilles concealing their drivers. You can remove these grilles with a little effort, but it’s best to avoid this. 

These headphones come with a new audio cable similar to what you’d get with the pricier models. It has a 3.5mm L-shaped termination with thicker and more durable cables with 3.5mm connectors for each driver. This supplied cable also features a nice black, rubberised sheathing that doesn’t tangle. 

HIFIMAN utilises a standard TRS 3.5mm jack plug, but it doesn’t feature a recess extension. If you use it with a rubber cover/case or a recessed jack, you can’t easily connect the wire. 


Generally, the HE400SE are comfortable headphones with ear cups that don’t feature large cutouts. It’s comfortable to wear for individuals with smaller ears, but those with large ears may disagree. 

The product’s earpads are soft, comfortable, and feel good on your ears. Even if you wear them for long hours, you won’t feel any discomfort.

The cups are deep enough, so your ears won’t touch the cups’ sides. Although these get a bit warm, they’re still cooler than closed-back headphones. 

Aside from the ear cups, the HE400SE’s headband is also notably comfortable. When we tried the headphones, the shape fit us perfectly, and there was also adequate cushioning on the ear cups. 

Its clamping force was nominal, and it felt secure without being too tight or irritating on the head. Remember, the headphones don’t fold in any manner. That means it’s mostly for indoor use and not on the go or while travelling. 

Then again, it’s something usual when we speak of open-back headphones. 

Stealth Magnet Technology with the HIFIMAN HE400SE Open-back Planar Headphones

A few years back, people began installing modifications on their planar cans. They did it to optimise their sounds by decreasing refractions. 

Manufacturers like Audeze made their version using Fazor technology with enhancements over the classic non-Fazor versions. Because of that, HIFIMAN came up with a comparable but more straightforward solution and implemented it on these headphones. And the company calls it the Stealth Magnet Design. 

By controlling and managing sound waves that pass through the magnet arrangement, HIFIMAN successfully removed refractions and sound interference. The company did it by decreasing wave diffraction turbulence. 

It’s the equivalent of sound bouncing off objects and walls from speakers to reaching your ears off-phase at differing times. This occurrence causes sound purity degradation and phase issues. 

The company created a magnet cluster that’s close to being sonically invisible. It avoids interfering with sound waves from the diaphragm while it reaches the ear cups. To us, HIFIMAN did a successful job in achieving this feature. 

Key Features of the HIFIMAN HE400SE Open-back Planar Headphones

What are the unique features of HIFIMAN’s new headphones, and what makes them better than their competition? Let’s find out in our HIFIMAN HE400SE Open-back Planar Headphones review.

Planar Magnetic Design

Conventional headphones use dynamic drives that diffuse a sound wave through vibration, but this doesn’t move the whole membrane. The planar magnet design utilises conductive layers to cover most of the membrane for improved movement capacity.

The architecture of the HE400SE reduces a considerable amount of distortion and improves the quality of rendered audio.

Stealth Magnet Technology

The Stealth Magnet is a unique design that lets sound waves pass through the magnet without interference, unlike conventional magnets. As a result, it reduces diffraction and prevents losing the integrity of the sound waves. This technology allows for delivering rich and highly accurate sound across the entire frequency range.

Comfortable Listening with the HIFIMAN HE400SE Open-back Planar Headphones

With the newly designed ultra-lightweight headband, you can use the HE400SE for hours without any discomfort. At 390g, the headphones are lightweight and comfortable to wear. Although it has an adequate clamping force that keeps the headphones secure, it’s not too tight to cause fatigue.

The speakers have a sturdy and durable casing that provides protection.

High Conductivity Cable and Maximum Compatibility

The HE400SE’s detachable cable uses copper and silver conductors for high conductivity. Also, the headphones come with a 6.35mm adapter for compatibility with a wide range of devices.


Knowing the specifications of a product is essential. And that’s why we’re discussing it in our HIFIMAN HE400SE Open-back Planar Headphones review. 

This product is an open-back, planar magnetic pair of headphones with a frequency response of 20Hz to 20kHz.  It has an impedance of 25Ω, a sensitivity of 91dB, and it weighs 390g. 

Hands-on with the HIFIMAN HE400SE Open-back Planar Headphones

Now, we will share our hands-on experience with the headphones in this HIFIMAN HE400SE Open-back Planar Headphones review. We used it for over a week to see how it would fare. 

We tested everything we could to see if it performs better than its competition or if we should look elsewhere. And for starters, the HE400SE is an amazing-sounding pair of headphones with a neutral sound signature. 

If we had to compare, the product sounded like HIFIMAN’s more expensive pair of headphones, the Sundara. They’re pretty much the same, save for the lower price tag. 

So if you’re on a budget but love how the Sundara sounds, we suggest going for the HE400SE.


We’re starting with the best part of the headphones’ sound – the treble performance. When we listened to audio using the product, its treble was lively and articulate in delivering sounds. Unlike the mids and bass, the treble peaked freely, thus, giving us striking tones than constant smoothness.

On most tracks we listened to, it came through beautifully with the right amount of energy and sparkle. We were pleased with how it completed the soundstage since the clear upper highs offered instruments and effects the right sizzle. 

Although sometimes, the treble got too bright at some points in the frequency range. However, it wasn’t a common issue with content that’s well-recorded. 

Low-end and Mid-range of the HIFIMAN HE400SE Open-back Planar Headphones

The mid-range response of the HE400SE was also good. It tracks efficiently through most of the range, resulting in adequate delivery and a strong presence for male vocals. 

Keep in mind that the mid-range isn’t perfect. It slightly faltered on the upper ranges where HIFIMAN introduced a dip from its reference tone. It resulted in pulling back female voices and a few string instruments. 

Some users may consider this a fair trade since our ears tend to be sensitive in this range. 

Pulled back responses sounded more pleasing, relaxing, and less shouty. Just remember that it isn’t accurate, so it can sometimes cause mixes to sound slightly hollow.

Fortunately, it’s easy to make up for the upper mid-range and low-end shortfall in the sounds by using EQ. Lots of headphone amps even feature a bass-boosting function that fixes bass deficits. But you’ll need to find another way to adjust the mid-range. 

Setting aside squabbles about tonality, the HE400SE impressed us because of its technical performance despite the lower price. Its drivers were nicely resolving and brought about fine details in our recordings. 

There was a satisfying level of layering and texture in sounds with instruments that occupied definite space in the mix. 


For the bass response, we consider it a mixed bag. Since it’s on the leaner side, it brought lots of impact and enjoyment when we listened to specific music genres. Planar magnetic drivers have a precise and fast bass response which these headphones deliver. 

Its bass was filled with impact and had noticeable detail and overall nuance. We consider it to have the most natural-sounding bass with the perfect amount of texture for most music genres. 

We loved the HE400SE’s low delivery since it was free from distortion and boom. 

Percussion instruments like smaller drums had excellent snap quality and timbre. Male vocals had adequate warmth without sounding too brittle or thin.  

However, the headphones have little to offer in the frequency range’s lower regions. Bass can be punchy, but there were no excellent rumbles or thumps to their sound. 

So while cellos and bass guitars still sound nice, the lower notes didn’t come through like how they should. We noticed this occurrence while testing the product for our HIFIMAN HE400SE Open-back Planar Headphones review. 

Generally, it’s a common issue with open-back headphones, but it looks like the HE400SE goes ahead in this regard.


Imaging is another evident aspect of the headphones. The HE400SE excellently created well-localised audio that made us turn our heads in the direction of the sound source.

Even in standard stereo recordings, the headphones sounded great. The vocals and various instruments had precise three-dimensional locations.


The soundstage of the HE400SE was as open as other HIFIMAN headphones having great height and width. These excellently layered images with articulation and clarity. We enjoyed the audio’s depth since the HE400SE delivered highly immersive sounds wrapping around our headspace.

The overall soundstage relied on a closer image than other HIFIMAN headphones communicating distance. But despite that, the audio still sounded natural.

Although its sounds were not completely holographic, it was highly engaging. It was also a surprise for open-back headphones at this price. 

The HIFIMAN HE400SE Open-back Planar Headphones for Gaming and Films

While testing, we found the HE400SE’s performance to be exceptional for games, TV shows, and films. While playing games with these headphones, we noticed the audio’s superior imaging and accurate object positioning. Technically, the HE400SE performed better than most headphones marketed for gaming.

When we used them for watching films and TV shows, the headphones sounded exceptional. However, particular sounds lost their boom and rumble.

We specifically enjoyed using the HE400SE for playing games, and we highly recommend it as gaming headphones. But note that it doesn’t have a built-in microphone and ambient noise cancellation.

HIFIMAN HE400SE Open-back Planar Headphones Review  Summary

With the HE400SE, HIFIMAN has proven that they are true headphone experts. They can offer both high-end and affordable headphones without compromising quality.

This product is excellent in terms of price to performance ratio. It’s the best when it comes to overall clarity, detail, and dynamics.

Aside from audio, we noticed that HIFIMAN is improving its headphones’ build quality with better cables, sonics, and other features. Using this model is also more enjoyable since it provides the same comfort.

Overall, the HE400SE is an excellent pair of headphones offering high-quality audio, great design, and comfort in a budget-friendly package. Its punchy, dynamic, detailed, and natural sound is the best you can get for its price.

To learn more about the HE400SE Open-back Planar Headphones, visit HIFIMAN’s official product page for additional information.