HiFiMan HE400i Open-Back Headphone Review

I’ve heard on the internet the general word was that the HE-4XX used the identical cups and drivers as the original HE-400i and the headband of the HE-400 without the “I”, along with HiFiMan Focus pad earpads.

So with this new combination of the old HE-400i, the ear pads and the new headband as HiFiman perfected the HE-400i. Well, let’s get into it.

1.0 Physical Design

1.1 Headband

So first, let’s look at the physical construction. The most obvious addition to the HE-400i is the new headband design. This is the same headband used on the HiFiman Diva, but using black leather instead of a light brown; I think this looks much better than the Diva for comparison.

The HE-4XX use the same old-school-looking headband as the HE-400 and the E-500. I much prefer the looks of the old-school-looking headband design, but I found it lacking in comfort and adjustability. The original HE-400 I had an early version of HiFiman suspended headband design, which was criticized for durability issues.

Now, the Davis style change should solve those issues from the previous headband designs. In addition, I find the headband to be very comfortable. The clamping force is very light, and the headband has plenty of adjustabilities. All in all, I think that moving to the Diva headband design was a perfect choice.

1.2 Earcups and Pads

The HG-400i 2020 uses the identical familiar ear cups as the original and the HE-4XX. They are made with plastic cups with a mesh grill on the rear. The ear pads resemble the HiFiman focus pad design and original HE-400. However, there is a difference between the pads on the HE-4XX and the HE-400i.

The pads on the HE-4XX are called the focus pad A and both pads are hybrid designs and wed-shaped, but the focus pad A has no internal wall, like the focus pad on the HE-400i. It’s important to note that ear pads are a significant part of the tuning of any headphone, therefore, despite having the same drivers in ear cups, the HE-4XX and the HE-400i will sound slightly different from each other from those pad differences alone.

You can also tweak the sound signature to your taste by changing the pads. Speaking purely about comfort, I much prefer the focus pad on the HE-400i to the focus pad A on the HE-4XX.

For some reason, the pads on HE-4XX are kind of itchy and a bit too soft for my liking. The pads on the HE-400i have a bit more structure, and I find that they fit my head much better.

1.3 Cable

The cable connection method is the same as on most current HiFiman designs. The connection is dual-sided with 3.5-millimeter mini jacks and the length is around 1.2 meters and terminates in an angled 3.5-millimeter mini jack with a push-on quarter-inch adaptor. The cable itself is braided and not the most flexible cable around.

I do prefer a much more flexible cable myself. However, this one isn’t microphonic and doesn’t cause any vibration noise.

1.4 Technical Specification

HE-400i is still using the same drivers from the original HE-400 and the HE-4XX. They all use a planar magnetic driver with a single-sided magnet design.

The impedance is 35 Ohm and the sensitivity is 93 DB. The HE-400i is not super sensitive and not super easy to drive despite the low impedance. However, it doesn’t need a power station to go. Think the O2, the Atom, the iFi Zen Dac, or even most mobile phones should drive this headphone with no problem.

1.5 Pricing

And lastly, we’ll mention the price, which for HE-400i is $279. Again, this seems somewhat competitive, with the HE-4XX coming in at around $190 at the time of this review.

2.0 Sound Performance

All specific listening tests were done using lossless sources from a variety of genres using my JDS Atom as the amplifier of choice.

Although I did spend a fair bit of time using the HE-400i with the iFi Zen Dac, I’m going to say that I like how the HE-400i sounds along with the HiFiman Ananda. The HE-400i is close to my preferred sound signature as any other headphones I’ve tried.

2.1 Frequency Response & Overall Tonality

I had planned to do this review a little while back, but I find it kind of hard when a headphone does really well. There’s less than nitpick and I struggle to put it into words. I found the same with the Ananda, a headphone that is so quietly, superb.

And, of course, I don’t want to come across as a fanboy, but the more HiFiman’s headphones I hear, the more I realize that I really like HiFiman’s house. So, in terms of frequency, response, and overall tonality, we have another excellent-sounding headphone in the HE-400i. So, if you’re like me and prefer your headphones to be tuned similarly to the Harman target, then HiFiman always seems to fit in well.

2.2 Bass

So, the bass rolls off similarly to the HE-4XX and Ananda and the Sennheiser HD6XX, and, like most other open-back dynamics, it’s not super rolled off, but it doesn’t have the same extension of the Ananda or most close-back headphones.


But when it comes to bass quality, I think much like the HE-4XX and the Sundara, it sounds quick and articulate but not as plucky and detailed as the Sundara to my ears, but more articulate than the Sennheiser HD-6XX. I’ve always said that bass is the weak point of the Sennheiser HD-6XX. The HE-400i is probably more on par with the AKG K712 Pro than the Sennheiser HD-6XX.

I find the bass a little more present and more articulate on the HE-400i than I do the HE-4XX, as these share the exact driver. I assume this is related to the ear pad. However, I measured them with the MiniDSP Ears and the graphs disagree with my assessment.

It could be a seal issue with a measurement rig. It could be a seal issue with my own head. It could be in my head or simply a case of volume matching. Now, whilst they use the same driver, the pads change the distance of your ear to the driver, and a slight volume change could be enough to hear a difference.

The only drawback I have with the bass on the HE-400i is that roll-off. This is not a reflection of the HE-400i but open-back headphones in general. However, adding a few DB of EQ, say a shelf at a hundred Hertz, will be entirely subjective. However, I’ll definitely take the HE-400i over the Sennheiser HD-6XX in terms of bass quality.

2.3 Midrange

The midrange is a lot less colored than the HD -6XX. I like that mid-bass hump for a lot of music, but these days, I appreciate the added low-end clarity that the HE-400i has.

Along with plucky articulate, low end, this gives much more definition and less mud to percussion and bass guitars. However, they certainly don’t have the same energy and punchiness as the Sundara. The upper mid seems a little bit more restrained than the HE-4XX in a good way. I find the HE-4XX has a bit of glare in places.

With many other HiFiman headphones, the HE-400i has a minor recession between one kilohertz and three kilohertz, but the HE-4XX does seem to have a little more energy between one and two kilohertz.

Perhaps this little extra energy causes the HE-4XX to sound slightly more shouty or actually comparatively the HE-4XX vocals, even a little bit telephonic in places.

This is another win for the HE-400i versus the HE-4XX, just like every other HiFiman headphone I’ve tried, treble performance is excellent. With a good amount of detail reproduction, it’s not overly bright nor too dark. It’s another one of those Goldilock situations.

There’s more energy and extension than the comparatively veiled HD-6XX, but short of being bright and fatiguing. Perhaps some might find some issues with the elevation somewhere around eight to nine kilohertz.

This is something the HE-400i has in common with the HE-4XX and Sundara. But it never bothered me all that much and I didn’t find them sibilant.

2.4 Soundstage and Imaging

In terms of sound stage, like the Ananda and the HE-4XX, staging is pretty good. It was one of the first things I noticed about the HE-4XX when I first tried them and the HE-400i is very similar.

It’s not quite up there with the Ananda, and it’s certainly not up there with the K712 Pro, which has a width and depth that I’ve never heard before, but it blows away the likes of the Sennheiser HD-6XX imaging. However, it is a strange one because I always like the imaging of planar headphones, at least for getting lost in the music, but when it comes to gaming, I feel that the imaging just doesn’t cut it.

Instead of being able to place a sound source in 3D space, I feel almost as if the images mirage compared to a good imaging dynamic headphone like the Beyerdynamic GT-1990 Pro or even the AKG K712 Pro.

There’s a night and day difference, particularly in those games where accurately identifying a sound’s position is essential. For that reason, I can only recommend planar like the HE-400i for casual gaming where positional audio is not so important.

2.5 HiFiman HE-400i Versus HiFiman HE-4XX

Something else I want to note is an interesting observation I made between the HE-400i and the HE-4XX, considering they use the same driver and ear cup design, I can only assume this is down to differences in the ear pads unless there’s something wrong with my HE-4XX. I find my HE-4XX to have an almost reverberant or ringing quality.

Surprisingly, I don’t get this at all with a HE-400i. It’s hard to pinpoint exactly what I’m hearing, but the HE-4XX sounds almost like it is applying reverb, particularly to vocals and guitar leads for example. I don’t know what would cause this and if there’s something in the frequency response that would highlight this, but ignoring everything else for this reason alone, the HE-400i sounds much better to me than the HE-4XX.

My Verdict on HiFiman HE-400i

So, I think it should be evident by this point that I really like the HE-400i much more than the HE-4XX, despite them sharing a driver. The build is much better and the comfort is a considerable improvement. The headband design is much more comfortable, and the shape and padding of the ear pads are also much preferred.

And in terms of sound, whilst they have a very similar frequency response, I prefer the HE-400i. Whilst not a full base extension, they have a decent and articulate base, clear and detailed mids and high with a good treble extension and sound staging. So there is a lot to like about the HE-400i.

So for $279, are they worth it? Well, let’s take a look at the competition. They are priced more than HE-4XX by about $100. So, it is worth the extra $100 for the performance I get. The HE-400i is also much cheaper than the highly recommended Sennheiser HD-6XX and the new HiFiman HE-5XX.

The HE-400i is unquestionably the best value. We’ve already discussed the importance of the HE-400i versus the HD-6XX, but the Sundara is obviously the better headphone. It could well be the best headphone under $500.

However, the price difference simply rolls them out as competition. You also have the AKG K712 Pro, which is a great choice, but only if you live in Europe, as prices in the US are pretty steep.

The HiFiman HE-400i is now my best $200 headphone, and I recommend it to others looking for an open-back headphone in the $200 to $300 range.