HIFIMAN SUNDARA REVIEW: Versatile and maturely tuned Precision King



SOUND: 9/10
VALUE: 8.5/10

THE PLUS: Lightning fast transient response, Incredible Imaging, Transparency, Tonal Balance, Realist timbre, Well-controlled bass,  High resolution and details, Neutral yet musical, Sturdy construction, Good Value at 350$
THE SO-SO: No carrying case, cheap cable, attack lack a bit of snap and definition a bit of edge and bass a bit of extension (even if already incredible for a planar), was too expensive at 500$

Hifiman has a special place in my heart, not in the sense I’m a hysterical fanboi that loves everything they launch, but in the sense they have been part of my audiophile quest since a very long time. In fact, my first ‘’serious’’ DAP was an Hifiman HM601 and while it’s far from reference sounding with its warm bassy analogish sound signature, I was extremely impressed by its power output as well as open lively sound, it was the only DAP I own that can inject life to my headphones collection of the time (Grado Sr325i and GS1000, Fostex T50rp, Sennheiser HD590 etc). Then, Hifiman begins to launch earphones and sometime after they begin to launch their first Dynamic Headphones. I do own their HE300 and again, like the HM601 DAP, it was far from perfect and feel more like a prototype product than accomplished one. So, a love-hate affair begins with this company and extends further when I test their RE800 Gold which I found underwhelming again. Then, I test the extremely pricey RE2000 iem, and yes, I was blown away by its lush musicality. This is when I understand they earn a lot of experience in audio engineering and tend to try to push sound boundaries with new technology as used with topology drivers of RE2000 Gold and Silver.

11 years ago, the Hifiman revolution begins with their entering into high-end Full-Size Open Planar Headphones with the first HE5 model and then follow the HE6, HE5LE, and HE4 models. In 2012, price value was pushed to their limit with the launch of the mythical HE400 series. At first, this model was priced 400$ but fastly go lower with a new version, to finally stay in the 200$ zone. Now, the Massdrop version of HD400 calls H4XX is selling as low as 145$, which is just insane unbeatable value. Since this time, Hifiman never stops launching new ortho-dynamic full-sized headphones, perfecting this sound technology with every new models. In total, they have at least 13 Planar Headphones but the one I decide to review today is second most budget-friendly model call SUNDARA.
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As soon as the SUNDARA go down from 500$ to 350$, I know this can be the cheapest Planar headphones eng game some were waiting for. The fact that it has a sturdy metal construction, looks more comfortable than other models (including infamously uncomfy HE300) and most of all use a NSD orthodynamic diaphragm 80% thinner than all past models really make me obsess to test those.

Indeed, my expectation was incredibly high, but realist too, because I own a pair of Magnepan Planar speakers and know to some extend the particular sound transmission this technology offers. Until now, I was very unsatisfied with planar earphones compared to speakers, so what I wish to get with the SUNDARA was an open, detailed and delicate sound with a fast transient response that avoid any type of congestion, as well, I cross my finger that it does not sound too clinical or thin in timbre and have some proper bass response.

Let’s see in this review if my Planar dreams come true.

The Hifiman Sundara can be bought for 350$ from Hifiman Official EBAY store HERE.


Type: Over ear, open
Usage: Home usage
Driver type: orthodynamic
Pads: replaceable, slanted hybrid pleather/polyester cloth
Inner pad dimensions: depth: 20mm rear, 25mm front side, Diameter: 55mm
Collapsable: No.
Headphone connector: 3.5mm TRS (marked L and R)
Cable entry: double sided
Cable: replaceable,  1.6m. 3.5mm TRS with 6.3mm adapter
Nom. power rating:  not specified (assumed 1W)
Max. voltage:  6 Vrms (assumed 1W)
Max. current:  160 mA (assumed 1W)
Max. S.P.L. 122 dB (assumed 1W)
Frequency Response: : 6Hz-65KHz.
Impedance: 37 Ω
Efficiency: 94 dB/1mW  (108 dB/1V)
Weight: 372 g.
Clamping force: low/medium
Accessories: 1.6m. cable with 3.5mm TRS jack and 6.3mm adapter, booklet.


The SUNDARA has a very big orthodynamic driver of about 9-10cm diameter, it’s take the full space of headphones cups and have a square shape. It’s among the thinner planar diaphragm ever created with only 1 to 2 micron of thickness. This technology call ”Neo super-nano diaphragm” is stated to be 80% thinner than all previous Hifiman headphones.  This ”NSD” diaphragm promess extremely fast and detailed transient response.



The SUNDARA come in a luxury box, lying in a bed of black silky fabric like a precious diva.  It does not have any carrying case included, which is a little disappointing if we wanna protect this diva. Apart from the cable and the 3.5mm to 6.5mm jack, their an instruction manual and the warranty cards.


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These Headphones are real full-size open-back with big cups that will fit even biggest ears. This is quite big and heavy headphones, with its 90% metal construction, it has a weight of near a pound (372g), but due to its weight spreading headband, the heavyweight isn’t felt and make these comfortable for long listen. Quality of construction is very impressive for an Hifiman product, it feels well crafted with good attention to details, the metal parts are smooth and the thick metal cups have a special black painting that isn’t prompt to easy scratching. After 2 months of use, I have nothing to report about headphones durability, but I read some people have an issue with the planar driver behavior, perhaps I’m lucky, but they work as well as the very first day for me. These are 100% open-back, and the big metal grill is both beautiful and sturdy. Only part of construction I feel might be fragile is the plastic covering of metal headband, the type of plastic reminds me old Sennheiser Headphones which were easy to break, anyway, their no pressure on this plastic, just be cautious to don’t drop them on a hard floor or hit this part.


CABLE is about average, it’s a step up from the HE-300 in terms of flexibility and softness, but not in terms of component because HE-300 has a Silver plated braided cable. It looks similar to the HE4XX cable. We talk about a basic copper cable with inner wires that feel loose in its thick rubber body. What worry me with the durability of this cable is the two 3.5mm plugs that bent dangerously when you sit the Headphones on its cups, this surely can lead to cable damage.


COMFORT is really nice, while the headband diffuses the weight and form to your head for an ergonomic fit, it will not cancel totally it’s weight, perhaps this will be a problem for people with very fragile neck but personally, I never feel any long term discomfort with them. The ears cups are very big and the ears pads quite thick so you do not feel any pressure on your ears, in fact, perhaps it will lack some for smaller heads because as say, the SUNDARA is large and big headphones. About the pads, it would have been even better if a little thicker and softer so it seals perfectly around your ears, which is important to get the best sound possible. One thing certain, the SUNDARA aren’t portable headphones.


These are capricious headphones to drive, not the most difficult on the market, but even with a rather low impedance of 37ohm, their very low 94db sensitivity as well as demanding orthodynamic drivers made them harder to drive than lot of higher impedance Dynamic Headphones. To be safe, I would say you need a minimum of 2000mW@32ohm to push their dynamic range at full potential. Lower than 1000mW@32ohm amping will not do them justice and create a more closed sound lacking in bass impact and imaging accuracy. Read the PAIRING section for more info about different amplifier’s synergy.



Enjoying the SUNDARA is some kind of sacred audiophile experience that needs a meditative critical listening devotion. The unsaturated layers of nuances in musicality is like learning a new language, once well translated, with the help of best amplifier pairing possible, you discover the truth within its musical language which is an Elegy poem about the waves of transparent layers of sound. This isn’t your typical Planar headphones, this one knows how to sign with gradation, this one extends in both low and highs end effortlessly. Subtly balanced dynamic range, smooth breezy timbre, floatings mids as light and complex as feathers, delicate treble with otherwordly brilliance, the SUNDARA deliver a translucid ocean of sounds where we can contemplate for hours musical marine life. Even after 2 months of daily usage, these headphones still amaze me and learn me something new about timbre, tonality or imaging due to its fascinating articulation. In more rudimentary terms, the SUNDARA sound signature is airy, neutral with slight V shape bass, a hint of warmth in timbre, extremely transparent and fast in transient response but though the attack is ultra fast, it’s not too edgy, but rather soft in low and mids with some extra crispness in the treble.

SOUNDSTAGE is really unique, very tall and quite wide, it has a circular spatiality to it, sometimes you wanna turn your head to ‘’look’’ at the sound source, instrument surrounding you from every side possible. To achieve the best headroom level, you need to amp this sophisticated maestro well, otherwise, it will sound less open and airy.

IMAGING is one of the numerous highlights of SUNDARA, because whatever the numbers of instruments that play in the busiest music, it will play it at the same dynamic range, with same accuracy, definition and clarity. Again, it isn’t shown in a clinical way where it extracts some boosted highs or mids and takes it apart for you, it just divides all layers of sound equally and precisely. You swim in sound complexity and can pinpoint any instrument you want, even if the space between them isn’t boosted or lowered. Precise and highly revealing is the instrument placement, clear is the separation.

TONALITY is hyperrealist and has a high level of fluidity in balance. Yep, it has some liquid edge to its mid-range, avoiding any harshness or shoutyness to its vocal presentation. Tonal balance does have extra push in the treble but keep it laid back enough.

TIMBRE is transparent, wooly, soft on edge, smoothly textured and even unpredictable in nuance richness. I never heard anything like this before, and while it can be disconcerting at first and considered as warm or even dark, it isn’t as it have complex nuance to it that trigger your attention and ask for silent concentration.

BASS is fast, thigh and soft in impact. The extension is good, but they’re no sub-bass boost, so it’s not thick or heavy in the rumble. It’s rather flat full-bodied bass, with a slight boost in mid-bass so you can feel some slam when needed too. The texture is life-like, especially for an acoustic instrument like acoustic or slap bass, it’s not grainy nor dry, and do not bleed on mid-range. Separation is excellent even if definition is not very edgy, it’s hard to explain but the bass comes to you in a unique acoustic projection which makes it more appealing for the plucked bass line with natural extension than thick thumpy synth-sub already lacking in definition. Cello too sound light in weight but fast in attack and full in tonality. I would say that more you go up in frequencies range with the Sundara and more the definition became edgy and clearer, resolution always being at highest level possible.

MIDS are lean in presentation, ultra well layered with nuance in presence and attack. The level of transparency is incredible, as well as tonal representation. Vocal has a wide airy presentation to them, it’s not overly intimate and very natural in timbre with right amp pairing. The definition is rather soft, and I do not hear any unpleasant grain or sibilance even if they’re a slight push in upper mids that make female singer slightly more lively and present. An instrument like saxophone sound exquisite, full and airy, with a very articulate tonal modulation, adding it’s airy layers delicately over other sounds layers. The piano is a little less realist even if highly clear and nuanced, this instrument benefits extra weight in note impact in mid-range to be properly discernable in subtle pitch change which the Sundara timbre does not offer perfectly. When we listen to violin, this is again pure joy as if we can follow sound projection decay in spatiality, it’s not screechy or grainy, and attack is fast and precise, in fact, I rarely heard violin playing as beautiful than from the Sundara, it’s natural, airy, agile and highly accurate both in tonality and timbre. With this exquisite TRACK from Sokratis Sinopoulus Quartet, the Lyra sound so airy, natural, transparent and well-layered above other instruments, it’s near surrealist, as well, full-bodied acoustic bass stays in the back perfectly articulated, while well resolve piano and sparkly percussions are from each side.

TREBLE is most likely the more vivid and energic part of SUNDARA, but not in an aggressive unpleasant way, but delicately snappy one. These are very revealing sounding headphones and they easily dig lot of micro details. Strangely, I cannot consider these bright, but sure sharp and crisp, the highs are light in decay so whatever how fast is the percussions or instruments attack, it never mix or distort in transient response. As well, highs do not sound unbalanced with the rest of the spectrum, they stay in the back of mids and upper mids. Their definition is sharper than smoother mids layers. Acoustic guitar sound extremely clear, with a hint of metallic brilliance, it’s not as full sounding as I would like but make its articulation faster which sharpens overall imaging. Harpsichord has the same coldish treatment in timbre, but now you can listen to Pierre Hantai playing  BACH ”English Suites” and take apart all note individually. I’m not sensitive to treble, and though the SUNDARA isn’t light in upper highs, I think nobody will find them aggressive.




This Bluetooth DAC-AMP can deliver 240mW@32ohm with its balanced output, luckily, the Meze balanced cable fits the SUNDARA. I need to push the volume to MAX to have high volume enough, and while the sound is coherent and enjoyable, it feels little congested and bass is tamed. With instrumental music or not too busy track, like vocal-based music, it will sound quite good, very smooth and clear enough, but you got less articulation and very intimate imaging. This is not a serious solution to drive these headphones, just temporary ones when you wanna wander around your home without leaving the Sundara alone.

With Ibasso DX90+JDS LAB ATOM

The DX90 has dual sabre ES9018 DAC which deliver highly clear and accurate reference sound, but while the ATOM is powerful for its size with up to 1000mW@32ohm, the SUNDARA are the type of headphones that prefer having too much power than just enough. Well, I can’t say the ATOM doesn’t deliver enough power as it can drive SUNDARA at dangerously high volume without creating distortion, but I can’t say either it push the dynamic range at it’s best. The soundstage is deeper than wider and out of your head which affects mid-range layerings definition, the bass did dig low but isn’t perfectly articulate and nuanced, treble seems to be a little more laid back too, lacking some grip and air. Tonality is about the same, its more about sound openness and attack that feel tamed a little, still a very listenable pairing!

With Xduoo XD-05Plus

At 1000mW@32ohm, the Plus has no difficulties pushing the Sundara at very high volume, but the AK4493 DAC and overall total harmonic distortion level is higher than the ATOM so the resolution isn’t as clean and transparent. As well, the bass is warmer, but when you add bass gain it adds some very interesting punch weigh as well as warmer overall tonality that tends to thicken vocal presence. The SUNDARA are slightly cold sounding so this extra warm is welcome and adds pleasant musicality to the cost of affecting some technicalities like imaging precision and attack decay. If you want extra meaty SUNDARA, this pairing is an interesting one, especially when you upgrade OPamp.

With Xduoo TA-10

Now, we have plenty of power to drive the SUNDARA, with its 2000mW@32ohm, the TA-10 opens the soundstage and makes it airier without losing the cohesive transparency of the whole sound. Bass isn’t thick or super weighty, but more extended and controlled, the acoustic bass is wonderfully natural and full of nuances. Layerings is slightly liquid, very lively and realist. The whole sound is smoother, due to the delicate way of dealing with the treble. Still, timbre lack a bit of thickness to it, perhaps this is due to AK4490 DAC or the hybrid tube amping. Here we have reference sound which is very flat, a little cold but very fast in attack-decay

With SANSUI AU-D5 (vintage Japanese Linear A Solid State amp)

This extremely powerful amp might not be the cleanest one int term of THD, but I cannot even turn it at half volume before making explode my ears with the SUNDARA. Who know if it’s euphonic euphoria or the effortless power, but this amp injects life and musicality like no other. Bass gain body and extension without losing its control and transparent layering, the mids became more present and slightly warmer and thicker making vocal lusher and more lively. Treble too gain body, keeping a good amount of brilliance in high harmonic while feeling more natural and less bright. The soundstage is now finally out of my head, very airy and spacious, which is what I expect from open-back headphones. This is my favorite pairing and the one that shows what SUNDARA is capable of, both in terms of technicalities and musicality.



I listen to those for a full day and really think they are among the best headphones you can get under 200$. The sound difference between dynamic and planar drivers is more about transient response speed in busy tracks, while the HD58X isn’t bad, it will lose clarity and lack fast articulation in imaging that the SUNDARA offer. The soundstage is slightly wider with the HD58X, but taller and deeper and more holographic with Sundara. As said, imaging is more capable in term of clean layering, which make the Sundara more transparent in timbre too. BASS is slightly fuller and thicker with the H58X, as well, it feels it have more sub-bass extension, the slam is more impactful too, but the bass line feels better separated from mids with the Sundara. MIDS are fuller and more textured with the H58X, it has more body but less transparency, it’s more intimate too. TREBLE is notably more detailed and delicate with the SUNDARA, we hear more micro details while the H58X add texture with its lower and mid-treble, giving lusher overall sound.
All in all, Sundara technicalities are better which is evident in imaging and transient response, but the bass and mids of H58X are more bodied and natural. So, if you are into sound value alone, at 150$ the HD58X Jubilee is unbeatable.

VS MEZE 99 NEO (200$)

These are closed-back and quite portable compared to SUNDARA, as well, they are extremely light so more comfortable with people that have small ears, cause for me, they put pressure on my ears making them less comfortable for long listening. Again, it’s a dynamic vs planar competition here, but the NEO isn’t as balanced as the HD58X. Simply put, the NEO is so inferior to the SUNDARA that it’s a depressing job to do this comparison. Soundstage sound boxy and imaging mixed up and congested compared to the more open sound and transparent sound layering of Sundara. BASS is way more boosted, boomy and uncontrolled, with considerable bleed on mid-range, while it’s flat, clean and flexible with the Sundara. MIDS are more recessed, thinner, grainier and have upper mids boost that makes them sound sometimes shouty. TREBLE is less balanced, less snappy and can add splashiness to cymbals.
All in all, the 150$ price difference makes you go from entry-level sound to TOTL sound with those and we don’t talk about small benefit returns. The NEO sounds like an immature, fun-tuned, unbalanced boom-box compared to the ultra-refined, nuanced and technically talented Sundara.



HIFIMAN do an extremely impressive tuning job with the SUNDARA, it’s neither too warm or too bright and has a good amount of bass that is rarely found with Planar headphones. Once well amped, the SUNDARA show it’s true nature, which is an open, highly revealing sound with clear and airy imaging, beautifully balanced tonality and the fastest transient response I ever heard.

You can throw any music style to them, even the busiest classical symphony or jazz big band, and it will play it with articulate technicality, showing every instrument with smooth transparent resolution and snappy treble.

In the sub-500$ price range, their not a lot of choices for versatile Planar headphones, and while the HE4XX might be unbeatable in terms of value, the SUNDARA is surely the best deal for budget Planar ”End Game”. For 350$, this type of mature neutral sound is as much exquisite to listen to than revealing in technicalities, making the SUNDARA a perfect choice for those who search reference sound at an accessible price.


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