hifiman-RE400 Review

hifiman-re400.jpg I would like to thank Mark from Hifiman for providing these IEM’s for this review

I came across this IEM maybe 10 years ago - it was then a steal at $99 for its then reference sound. But allot has happened in the IEM market in 10 years so has this ‘old dog’ still got tricks for the ‘young pups’ of the IEM market. And mostly importantly how does it sound stack up against its competition.

Original launch

It can be funny to look back at old reviews for products that are still around, for example, here is Steve Guttenberg written Review (‘i.e. The Audiophiliac’) of the RE-400. The major complaints in this review and others from the original launch was the lack of a carrying case and a limited amount of ear tips. The price of the RE-400 at the time was $99 but unlike nearly every other bit of classic audio gear, the new RE-400 starts at an incredible $19.

Let’s see in detail how an upgraded RE-400 “waterline” stacks up - first lets have a look at what Hifiman now provides ‘in the box’:

Whats in the box:

So looking at what we get now with the RE-400, never let it be said that Hifiman do not listen to their customers feedback as the “new” RE-400 addresses these issues mentioned above immediately once you open the box.

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IEM and Cable

While the IEM itself is tiny and cable is permanetly attached, which for $19.99 that is perfectly fine but obviously more expensive IEM’s now have detachedable cables unlike when the RE-400 was launched. IMG_9071 Medium.jpeg


What I think is excellent is the sheer variety of sizes and even shapes of the ear tips provided and they have even provided some filter replacements. Different tips can have a massive effect on the sound profile and comfort of an IEM so having this variety is a massive benefit over similar priced IEMs.

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For such a tiny IEM, the variety of eartips sizes can greatly effect the comfort. For me and my large ears, I found the largest ‘fat’ tip provided excellent seal and was very secure in my ears during a few long walks. I love how they provided angled eartips also which no doubt will suit some people.

Because it’s so small, it is incredible lightweight and mostly you can wear this for hours without any discomfort, it never feel out of my ear and it lack of weight greatly helped it stay in place compared to much larger IEM’s like the Truthear Zero (see photos later), my one issue with the comfort was the cable. I found it caused some microphonics as it rubbed again my clothes. I did change its position to around my ear which greatly helped but it is something to bear in mind.

My wife on the other hand has tiny ears she loved the size of the small tip and she has now taken the RE-400 as per favourite IEM’s for comfort and sound quality.

The difference is size can be seen in these 2 photos: IMG_9069 Small.jpeg IMG_9070 Small.jpeg

Sound quality

So running through my long audiotext playlist - the RE-400 came across as very neutral, but does lack a little in the sub-bass region. As a sound signature, I thought it was more like the Etymotics ER2SR than the ER2XR, so bass heavy tracks like James Blake’s"Limit to your Love" didn’t have the bass punch you might expect coming from a Harman or V-Shaped IEM. But it more than made up with the with female vocal tracks - Kate Bush sounded amazing and Amy Winehouse had a liveliness that I have not often heard from IEM’s.

Midrange Clarity

Midrange performance is exemplary, delivering vocals and instruments with a natural and lifelike presence. This midrange fidelity is a testament to the RE-400’s engineering especially looking at the size of the IEM it is hard to believe it can make such beautiful sound, appealing to audiophiles who appreciate a true-to-source experience. It actually sounds more like a Sennheiser headphone than a Hifiman.

Realistic Treble and Imaging

High frequencies are handled with precision and without harshness, contributing to an extended and airy soundstage. This attribute makes the RE-400 particularly suitable for acoustic and vocal-centric genres.

Specs and Measurements

Some of the specification from Hifiman website:

Frequency Response 15~22 KHZ
Sensitivity 102dB
Cable Length 1.33m
Plug 3.5mm
Impedance 32 Ohms

With measurements, due to its size this IEM especially will highly dependent ear tips and there objective measurements especially of bass and treble with vary greatly.

But I thought this might illustrate what I believe is a good match for what I heard from the RE-400 compared with the ER2XR:


As you can see both are incredible similar until the treble region where each manufacturer has their own unique take on treble. I personally like the RE-400 more, that boost in the 5-6Khz region provided excellent dynamics while to me was not fatiguing even listening to albums likes Portishead’s Dummy.


Here is a comparison of the sizes of some similar priced IEM’s, the difference in size is remarkable with the Truthear Zero Red on the left, the Moondrop Chu in the middle and RE-400 on the right: RE-400-comparion Medium.jpeg

Sound quality wise the Truthear and Chu have more sub-bass both targetting that Harman curve but the RE-400 is much more balanced especially in the midrange. Basically if you want a reference IEM’s go for the Hifiman if you want a ‘fun IEM’ go for the Truthear. I would probably not recommend the Moondrop Chu due to its poor treble response, though its a similar price to the RE-400.


I gave the RE-400 an overall pragmatic rating of 4, what you get for it’s price is amazing, its sound profile isn’t perfect for everyone being that very neutral but it can hold its own against much more expensive IEM’s that also go for a similar profile. Now that it’s priced at the lower end of the market its remarkable that you can get this level of quality, making the RE-400 a good pragmatic choice.


The Hifiman RE-400 is a remarkable contender in the in-ear monitor market. Its focus on delivering an accurate and balanced sound profile makes it a prime choice for audiophiles on a budget. While its non-detachable cable may not appeal to everyone, its sound quality undoubtedly places it among the top performers in its price range. The RE-400 is a testament to Hifiman’s commitment to high-fidelity audio, packaged in a practical and everyday use design.