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Note: Audio Advice has since dropped HiFiMan from their lineup due to ongoing Quality Control issues, and in a way I don’t blame them. More on that in the article! Strap in and sit back because it’s going to be a wild ride!
Hey there friend, and Welcome aboard!!
Before we get into the HiFiMan HE4XX vs. 400i vs. 400S vs. Sundara MEGA shootout, grab a snack, sit back and relax because..
I have had the opportunity to demo all of these headphones on numerous occasions, in various settings, and with a plethora of different amplifiers dating back to around 2017.
When I started frequenting my local Audio Advice back then, the 400i was one of the first really good headphones I ever tried out. Before they started using the incredible NAIM DAC V-1 for headphone demoing, there was of course the famed Bryston BHA-1 – still the best Amp that I’ve personally ever tried.
I’m not going to tell the story again as I’ve talked about it ad-nausea, but the combination of the 400i with the Bryston and a FLAC file of Over the Hills and Far Away by Led Zeppelin really made me stop and go “Yeah now I kind of understand why people obsess over this sh**”
Lol. My opinion of audiophiles and this whole prick waving contest has definitely shifted over time, but I digress.
Since that day I haven’t really experienced anything close to that moment, save for a Chord Mojo paired with a MrSpeakers Aeon Flow Closed. The other eye opener was the Audeze LCD-3 and Bryston playing Pink Floyd’s “Time.” That was also a face melter for different reasons which we won’t get into today.
The point is that I feel comfortable enough in going back and forth with these and giving a rock solid recommendation. Part of that is because I understand and have experienced first hand some of the pitfalls that come along with having a HiFiMan headphone in your possession (it’s both a blessing and a curse), but also how they all sound in relation to one another.
Material: ABS Plastic, Polymer, Spring Steel, Synthetic Leather.
Weight: 12 Oz. (350/360 grams)
Color: Silver with Black trim
Cable Length: 1.5m
Sundara (सुन्दर) is a Sanskrit term meaning “beautiful, lovely”, or generally “noble; well, right”. As a personal name, it may refer to: Maravarman Sundara Pandya, Pandyan king, who ruled regions of South India between 1216 and 1238.
Material: Spring Steel, Synthetic Leather, Anodized Aluminum, OFC Copper Cable.
Weight: 372 or 379g. No concrete number on this.
Color: Black, Silver.
Cable Length: 5ft.
Now that the technical crap is out of the way, let’s dissect build.
Well.. this is about to get complicated.
The original 400i that I have been demoing since 2017 has never had one issue, and has likely been through hundreds (if not thousands) of different hands.
Before Audio Advice dropped HiFiMan from their lineup in 2020, it would sit on the shelf unscathed, even despite many people handling it and using it (in store as well as at home).
I took it home on numerous occasions and never had any trouble. Then I started hearing about people having problems with it breaking down, but couldn’t figure out why. It wasn’t until I stumbled across a post on Reddit that talked about HiFiMan outsourcing cheaper materials for the headband in the newer production line of 400i’s.
Then it all made sense; the one I had demoed for so long was part of the old production run. Don’t ask me why they decided to use cheaper materials, but it’s been a downhill QC issue fest for them ever since. A lot of the newer models have issues with anything ranging from:
The cable shorting out/sound cutting out on right or left channel.
The headband yokes breaking.
The headphone just falling apart.
The original Focus Pads coming unglued (worst design choice ever).
And so on.
The good news is that regarding the 400S, I’ve never really heard of folks having issues, and I have not either. The problems mostly stemmed from newer 400i’s and still do to this day.
Fortunately for us, the birth of the Sundara in 2018 fixed pretty much all that was wrong with the build quality of the former. Sorta.
It streamlined the design and replaced all of the plastic with a rock solid and robust metal. The headband padding retained the look of the 400i and 400S, but the piece over top supporting it rounded off in a much more aesthetically pleasing way. The pad itself also seemed to be made from a better quality material.
The headband adjustment itself (The small piece that you use to move the pad up and down), was also replaced with a more reliable piece of metal on both sides.
The same 3.5mm terminations appear on all 4, but the ear cups on the Sundara no longer swivel like they did with both the 400i and 400S. All 4 terminate in a 3.5mm jack as well and come with a 1/4″ adapter.
Drop’s (Formerly Massdrop’s) newer model 4XXdoes hearken back with those same swiveling cups, but they still don’t swivel all the way around (90 degrees) like they did with the originals.
Notice how both the original 400S and 400i above fold flat in the same ways, and also move and contort in a myriad of ways. They tended to move around a lot more freely.
With the 4XX, it stops at around 45 degrees now, while the Sundaras don’t move or rotate at all. I kind of enjoyed the swivel action, but in the grand scheme of how the headphone sits on your head, it’s not really that big of a deal.
All 4 sport the same circular comfy velour pads, but they are still the Focus pads, and they’re still awful. My issue with them is not that they aren’t comfortable, but that they’re built horribly and utilize poor design choices with regards to the piece of faux/protein leather on the back that wraps around the cup and attaches.
It should be noted that the original 400i had a protein leather outside with the velour seen on the front of the cups. The 400S’ original pads were all velour. Inside them all is of course memory foam.
As for the piece of protein leather, it’s haphazardly glued on and ends up peeling over time if you tend to switch out ear cups a lot. If you don’t do that, but only replace the cups when they wear out, it’s not really an issue because you’ll only be swapping once and then not handling them at all for awhile.
If you do a lot of pad swaps though, the material will break off from the plastic and leave you wanting to gouge your eyes out. Trust me. I’ve read plenty of reviews that echo the same sentiment and have had it happen to me on more than one occasion. In fact, I had to glue back the one from Audio Advice because it just fell the f apart. Not cool man.
The great news is that there’s a company called Dekoni that makes really really good sheep skin replacements for all of these headphones. They do run a bit pricey but you’ll see why they’re worth it below.
There’s no glue needed. The piece (now sheepskin) still wraps around the plastic, but notice how there’s more real estate. With the old cup, they glued a tiny sliver of it around it’s circumference and called it done.
Yeah that’s not going to lead to issues down the road .. said no one, ever.
It gets on my nerves thinking about it, but I digress.
The Dekoni’s are the preferred option for sure. They’re also very comfortable and plush as well. An all around great product that should have been HiFiMan’s own creation from the start. Ah well. Live and lear.. well no. I can’t say that about HiFiMan either. Because HiFiMan didn’t learn. They keep pumping out headphones with connection problems and sh**y pads.
Alright I’ll stop.
I’ll put it to you this way: Would you rather just pay for the Dekoni’s up front (a quality product) and have zero headaches down the road, or would you rather spend more money later when you have to keep replacing the originals because they suck and fall apart?
Ok I’m done for real.
Some of the other differences between these 4 are fairly minor. The Sundara boasts a somewhat updated “look” and feels more aesthetically pleasing than any of the others. The lattice grilles are in stark contrast to the honey comb configuration of the 400i, 400S, and 4XX, but that’s really about it as far as the outside of the cup. The Sundara just feels extremely solid to the touch and I think you’ll definitely agree that it’s a marked improvement over the earlier models when you finally hold one in your hand.
The 4XX is a bit of a different animal altogether when it comes to build.
The headband is an awkward looking piece of steel (I assume) wrapped in an odd, somewhat messy piece of stiched faux/protein/whatever leather. It just clashes with the rest of the headphone in my opinion.
The bales of the headphone are a robust spring steel, but the adjustment itself is basically a round piece of plastic and feels like it’s going to snap over time or something. The combination of materials here is strange, and feels like an afterthought rather than a carefully planned protocol.
One issue I’m having with the 4XX is that the silly right adjustment won’t even move up or down. It’s one of those things that you don’t want to mess with because it feels like applying too much pressure is going to result in the same phenomena that happens when your Grandpa tells you NOT to reach down into that freshly opened cereal box for the toy and you do it anyway. XD
In other words, an earth shattering explosion and subsequent mess on the floor. Rest in Peace Grandpa. Anyone else miss their Grandpa?
The piece that’s used to adjust feels so stiff and rigid, but doesn’t really move freely up and down which is could be a problem if you’re unlucky and get a bad apple. It feels like trying to adjust the headband is going to result in a broken mess. The left side does adjust, but you’re kind of having to really labor to get it up and down.
It might sound like I’m tearing this headphone to pieces (figuratively lol) but other than that glaring issue it’s not a badly built headphone. I’m just not sure I would fully be comfortable relying on it for the long term is all.
Some others have reported issues with the small hex screw that goes into the ear cup (pictured above), and honestly I can see why. Who would ever think it a good idea to drill steel into plastic? That’s a story for another day, but the main takeaway is this:
You get what you pay for. The 4XX is roughly $130 on Drop most of the time. Does it feel solid in your hand? Absolutely. It’s actually heavier than both the 400i and 400S. It doesn’t feel cheap at all when you’re holding it, but some of the decisions they made in actually putting it together are a bit suspect in real world practice.
The other issue is that of the sound cutting out, but thankfully that doesn’t apply to the 4XX. I never have had an issue with it on the Sundara, but I have with the 400S and 400i. The Ananda also had the same issue, which is in part why I think Audio Advice just got fed up with it. I remember telling them about it on a few occasions and I think they finally got the hint when their customers kept complaining.
That’s neither here nor there though.
The overall winner here is definitely the Sundara. I haven’t had any issues with it. It’s the one bright spot in another wise dark history with regards to quality control and HiFiMan.
400S: L-shape, braided, 3.5mm termination, splits off into a Y for each cup.
400i: L-shape, braided, 3.5mm termination, splits off into a Y for each cup.
4XX: L-shape, traditional, 3.5mm termination, splits off into Y for each cup.
Sundara: L-shape, traditional, 3.5mm termination, splits off into Y for each cup.
So what about comfort?
Thankfully, the comfort on all of these is very good, to the point of you being able to wear them for long periods with minimal adjustment.
They fit very well on your head, with a nice enough clamp pressure to feel snug but not overpowering. For comparisons sake, something too snug would be like the feeling of a Sennheiser HD600 fresh out the box.
Both the 400S and 400i are lighter than the Sundara and 4XX, with the S version being the lightest out of the bunch.
* = Reports may vary. My scale weighed the 400S at 360g.
Sundara: *372/379g. Tyll weighed it at 379.
It’s interesting to note that all websites I’ve seen claim 370g for the 4XX when that number isn’t even remotely close.
It is the heaviest out of the bunch, and as I mentioned earlier, feels more substantial in your hand.
with the Dekoni pads you’re adding about 11g to the overall weight, but it doesn’t make them really feel all that much heavier on your dome.
The 4XX’s headband padding is kind of “meh” in my opinion, in both look and comfort. I find myself adjusting them when they’re on my head way more often than I do with the others. The feel of a 400S on my head right now is similar to the feeling I get wearing an HD600. In other words, blissful. Wearing both is like receiving a warm hug from an old friend.
With the 4XX, I find that the headband tends to dig a little into the top of my head over extended listening sessions. Because the 400i and 400S are lighter, the thin sliver of padding works extremely well. The Sundara’s also have a thin pad and I find it works just fine too, even despite the headphone being a tad heavier. The headband padding on the Sundara is also a slightly different material as I mentioned earlier.
All in all, comfort is borderline exemplary for the Sundara, 400i, and 400S, and maybe average to slightly above average for the 4XX. You’re not going to be adjusting the former much, but with the 4XX you will be doing so a bit more often.
Let’s talk sound.
Sound & Imaging
Source: Tidal Hi-Fi, Spotify Premium
Amps: iFi Zen, AudioQuest DragonFly Red, Bravo Audio Ocean, many more (See Amp Section)
I’ve always felt like the sound of the 400S in relation to the others presents the most stark contrast, but in the grand scheme of things they all do sound very similar.
The main difference between the 400S vs. the rest is that it’s bass rolls off considerably more, and does sound a bit lean by contrast, even though it’s still immensely textured and detailed. This kind of makes the 400S sound cooler, a bit more sterile, and a bit more crisp, if a tad grainier in comparison to the warmer sound of the 400i and Sundara.
The Sundara to me was like a cross between the 400S and 400i. I felt as though the 400i at times could sound a bit too warm, as if it was lulling you to sleep (similar to the sound of the HD650). The relationship between the Sundara and 400i is similar to the one between the HD600 vs. HD650 actually.
In past articles and videos, I described the 400S as sometimes trying a bit too hard to impress you, whereas the 400i is more laid back and doesn’t really care what you think. That sentiment still mostly remains, but what I like about the 400S is the treble. It sounds nearly perfect, and doesn’t have that bite or sizzle that is present in the 4XX and 400i.
The Sundara definitely remedied that treble issue as well, and is probably the most relaxed out of all of these.
So in short, both the 400S and Sundara won’t get bitey/essy in the treble, whereas the 4XX and 400i will.
The peak at 9-10k is more apparent in both the 400i and 4XX, and it sounds a bit too peaky which results in some extra sizzle that isn’t really necessary. In fact, in the case of the 4XX I think it kind of almost ruined the overall sound signature.
With the 400S and Sundara, the treble sits better in the overall mix and really never gets out of line.
On all 4, you’ll notice the mid-range tends to roll off a bit after 1kHz, which is in large part what gives the headphone it’s relaxed type of character. All 4 also slightly rise back up around the presence region (3kHz), which to me sounds just about perfect. I’m never feeling like the vocals or instruments stand out too much like I do in listening with an HD600, and I’m almost never turning down the volume because of an unnecessary amount of “forwardness.”
One of the coolest (no pun intended) things in revisiting the 400S right now is the same amazing detail and spacing is still present exactly how I remember it. It’s still a very natural sound, and has always been a perfect entry level planar headphone because it doesn’t break the bank, but also sounds marvelous. What is a Planar Magnetic Driver?
In Sufjan Stevens’ “Tahquamenon Falls” I’m hearing an extra layer of detail and subtlety that is simply not there with other dynamic driver headphones. What is a Headphone Driver? The same composition feels more intimate and delicate with a 400S than it does with even a K702 (and that’s saying a lot considering how great the 702 is). Sufjan’s voice especially feels a little bit more dynamic, as if he’s closer and in the vicinity with you. Not a night and day difference, but definitely noticeable if you’re paying attention.
Fortunately for us, the 400S almost demands your attention. I had to stop a few times in writing this just to take it all in, marveling at how well the music is portrayed. It really is something to behold, and makes you want to revel in the experience a lot more than your typical headphone would.
I would say the sound of both the 702 and 400S is very similar, but there’s just something about the 400 series that renders music better. It’s hard to explain. Notes have better attack, sustain, and decay. They trail off better and feel more fully fleshed out. A great example of this (and specifically excellent decay) is Shallou’s “Begin” feat. Wales.
Overall, you’re able to hear more subtleties in the human voice, and how certain vocal inflections may sound in reality. Tracks that you’re very familiar with and have been listening to for years may sound slightly foreign to you!
In that sense, the 4XX does mostly stay true to the original 400i. In my notes I wrote down a reminder to describe the link to the 400i and it’s Timbre after listening to “Anemone” by Slenderbodies with the 4XX. With this song, I was immediately reminded why I loved the 400i so much when I first heard it back in 2017. Fortunately, the 4XX still captures that same magic and sounds mostly marvelous (outside of the treble issue). The sound of the fret-board at :57 seconds provided an almost insane level of resolution and Timbre, with the character of the instruments standing out in a way that simply doesn’t with other headphones.
This is one of the best things about owning a headphone of this caliber. It makes you excited about listening to music again. One of the best examples I ever read concerning this idea came from an Amazon Reviewer. He described the sensation of it in terms of “rediscovering the music that had long since been forgotten about.”
In my Focal Utopia Review, I described the phenomena like opening doors. Door 1 is what 99% of headphones will portray. Door 2 digs a little deeper, and Door 3 opens up nearly everything that a song has to offer.
With the 400S, it feels more like an extra layer gets peeled back to reveal even more going on beneath the surface in the song mentioned above, at about halfway through. It’s like the instrument keeps on revealing more of itself, it’s character, it’s Timbre. What is Timbre? The soul of the artist behind that instrument is explored more deeply. The way it sounds in real life vs. what it sounds like through a device. You’re still listening to it through said device (Amp + headphones), but the presentation of what you’re hearing is more accurate and true to life if that makes sense.
On “Holland”, many of the same sentiments apply. Sufjan’s guitar just sounds incredibly lifelike and detailed, but delicate in a way that simply astounds me. It’s almost like catching lightning in a bottle.
Soundstage on these headphones is also above average, but it doesn’t have as much width or depth as something like a K702. It’s getting there though.
You’ll be frequently:
Taking off the headphones to look around.
Pausing the track to figure out if the sound came from the song, your apartment, your house, or even outside!
A combination of all.
With the K702, you’ll most certainly do more of this, but the 400 series is not far behind with regards to the overall spaciousness of the image.
A headphone like the 600 is very narrow in terms of Soundstage, but still has good instrument separation. It just doesn’t have very good width or depth. It’s a bit below average in that regard.
A headphone like the 400 series (400S, 400i, 4XX, Sundara) is better than the 600 series and improves on all of those things.
A headphone like the K702 takes it a step further, improving on the 400’s by providing an even more immersive experience with regard to Soundstage and Imaging. As far as the overall sound experience itself though? I would give the slight edge to the 400 series.
Let’s take a break and watch a video..
Don’t forget to leave me some love! <3
What about amplification? Will you need an amp to drive these?
Amplification & Genre Pairing
Absolutely. But don’t get too carried away.
400S – 22 Ohm Impedance/98dB Sensitivity
400i – 35 Ohm Impedance/93dB Sensitivity
4XX – 35 Ohm Impedance/ 93dB Sensitivity
Sundara – 37 Ohm Impedance/94dB Sensitivity
The 400S is the easiest to drive out of this lot, as you can plug it into your phone and get loud enough levels with most newer devices sporting better internal DACs. Beginners Guide: What is a USB DAC?
On paper, the others will need some juice from an amp to reach acceptable levels, but they aren’t that much harder to drive. I’ve never had an issue with anything I’ve used, even something like an E10K or K3 from FiiO will work.
Good efficiency is somewhere in the ballpark of 98-99dB, and anything above that. 97dB sits in a middle ground (HD600), while anything below that isn’t efficient at all. AKG headphones also reside in this area, mostly coming in at around 91dB or thereabouts.
Fortunately, the Impedance of these models is also low, meaning they won’t resist the power being fed into them. This is what kind of makes them fairly easy to drive, all things considered.
As mentioned in the open, I’ve demoed each of these with a wide array of different amps:
The list goes on. Here are all of the Amps & DACs I’ve listened to thus far if you were interested!
I would say the Bravo Ocean paired with one of these is probably going to sound ever so slightly better than the others being that it’s a Class A Tube Hybrid, but it’s not a huge difference. I really did enjoy the pairing though, specifically with the 4XX. It helps in providing a liquid smooth, buttery sound, but any of the other Amps also sound great.
What’s great about the DragonFly Red is that you can reap the benefits of Tidal’s MQA while still running it into the Bravo Ocean via 3.5mm interconnect.
The DragonFly Red in this sense becomes especially useful if you purchase it first, but then decide to upgrade Amps later on down the road. You can use it with your phone, as an Amp with your PC, or as a DAC into another Amp. It has loads of power and sounds great with every headphone I’ve used.
With the E10K or K3, the same concept applies. Let’s say you bought one of those to get your feet wet. They’re cheap and sound great, so it’s understandable. I still have both in my studio. Because each have line out, you can easily upgrade amps down the road if you need more power. In that way, the K3, E10K, ad DragonFly Red become incredibly versatile in studio as you can mix and match with any headphone amp that supports line in or RCA in.
The other great thing about these headphones is that they all do very well with a wide variety of genres. To get an idea of what’s good, I mostly listen to Hip-Hop, Indie Pop, Rock, some Metal, Classical, Jazz, Downtempo, Folk, Acoustic, and Ambient music.
All of these genres and more sound fantastic with any of the 4 headphones. I find that, like the K702, quieter passages also sound incredible with these, and sometimes even better than any of the other genres. I would say the 400 series renders Jazz very well, but perhaps not quite as good as the 702.
What’s also amazing about the sound of these headphones is that they will really appeal to bass heads looking for a more realistic type of low end portrayal. As a recovering bass head, I used to think headphones like the M50x and V-Moda Crossfade M100 were what you went for if you were craving some slam and impact. While I still hold both in high regard, they aren’t something I gravitate towards anymore.
When I listen to Hip-Hop nowadays, I desire impact, but I also want to actually hear the individual notes better, and experience the sub-bass extension that the 400 series provides. The 400S is perfect for that, as are the rest of these.
With that, what’s the final word?
Recommendation & Final Word
The sound of these headphones is pretty similar across the board, with some subtle changes here and there. Overall, the 400S is the easiest to drive, and also presents the largest sound signature discrepancy. Even so, it’s still a pretty similar sound to the others in the grand scheme of things. The bass is a bit more rolled off, and it’s treble isn’t peaky like the 400i and 4XX’s is. The mid-range on all of these headphones is more or less the same.
Out of the 4, I’d recommend the 4XX if you just want a taste of the audiophile planar sound at an affordable price, and the Sundara if you’re wanting to splurge a little. The 400S will have a better treble response, but you may have build issues with the cables going into the ear cups. Because of that, the 4XX is the recommended solution.
I can’t recommend the 400i anymore because of QC/build issues, but I haven’t heard of anyone having trouble with the 400S. Right now I’m borrowing my friend Luke’s model and he’s never had any issues with it either. Edit: I was having an ever so slight problem with sound cutting out on the left channel, but it’s nowhere near as bad as it was with the Ananda. Still, I’d probably just go with a 4XX over a 400S because of that.
Something to also keep in mind is that while I was having some problems with the headband adjustment on the 4XX, you may not. It’s not going to manifest in every single model. I also have not had any issues with sound cutting out on the 4XX, so perhaps they rectified that with the Drop collaboration.
The Sundara is the best solution out of this group hands down. It fixed all of the 400i’s build issues, is more solid and robust than the rest, doesn’t have headband or cabling problems (in my experience), and also boasts a more relaxed treble presentation. Do be aware that your mileage may vary. There’s always a risk in purchasing any set of headphones, as they mostly all still have flaws and are never perfect.
As far as the Bass on the Sundara? It’s response is similar to the 400i and 4XX’s, and overall sounds very textured and refined while boasting some nice slam and weight. While I would not outright recommend any of the others at the drop of a hat, I would in the case of the Sundara.
Out of everything I’ve heard up to this point, only the 6XX stands in front of the Sundara for best audiophile headphone under $500 (and it is pretty much a photo finish).
Stu is determined to help you make sound decisions, and strives to deliver the best and most in depth content on the internet! In his spare time, he likes to fish, paint, play guitar, pray, rap, make beats, take photos, record videos, graphic design, and more. His sense of humour, coupled with a knack for excellence and strict attention to detail are what allow him to stand out in an crowded industry.