HIFIMAN Sundara Closed-back Review: It's... Different?

Sundara, but cheaper, which isolates the sound better, and is even easier to drive? Nope, not even close. Let’s talk about it.

But before that, I need to state one important thing - I’m really, really not a fan of their sound. These are, so far, my least favorite sounding headphones from HIFIMAN. I wouldn’t really say that they are objectively bad, and I’ll stay as transparent and objective in this review as always.

The Sundara Closed-backHeadphones with sealed ear cups providing isolation from ambient noise; the trapped air behind the driver affects bass tuning and often produces a more intimate sound. is a closed-back planar magneticA driver using a thin membrane with embedded conductors suspended between magnets, producing sound from the entire surface for very low distortion. over-ear headphone. It features HIFIMAN’s Stealth MagnetsHIFIMAN's asymmetric magnet geometry on their planar magnetic drivers, designed to present a more acoustically transparent surface to the diaphragm and reduce wave reflections that would otherwise distort the response. technology for reduced reflections and diffractionSound bending around objects or edges, causing interference patterns; speaker cabinet edges cause treble-band diffraction that affects off-axis response., which supposedly results in dramatically improved sonic output. It’s also equipped with the NEO Supernano diaphragmThe vibrating membrane in a transducer that converts between electrical energy and acoustic waves; its mass, stiffness, and damping determine driver character., resulting in fast response and detailed image with lush, full-range sonics - according to HIFIMAN. We’ll take a look at these qualities later.

It used to be priced at $399, but it has been consistently on sale for $229, and I think at this point that’s its regular price.

Build and Comfort

The Sundara Closed-back has a suspension strap headband design, familiar from the Ananda or even the open-backHeadphones with perforated or meshed ear cups allowing free air exchange; produces a more natural, spacious presentation with no isolation from ambient sound. version of the Sundara. It doesn’t swivel, and its adjusting mechanism isn’t the greatest, as it leaves scratches in the painting while adjusting. Either way, I still prefer it over the solid headband piece any day of the week, as I find it much more comfortable - it gets rid of any hotspots.

The earcups can freely tilt and are made of this beautiful real Beechwood, which gives them a fairly solid feeling in the hand, but also adds some more weight. It uses dual 3.5mm connectors located on the bottom of the earcups - they’re slightly tilted forwardA tonal character with elevated upper midrange or lower treble that pushes vocalists and lead instruments ahead of the mix; can sound exciting or fatiguing. to improve comfort, so the cable is not hitting your shoulder.

The pads use three different types of materials - perforated protein leather on the inside, cloth-like material (likely polyester) on the part that’s in contact with your skin, and solid protein leather on the outside. We all know this approach to the pads from other HIFIMANs.

However, there’s something different this time. They used a different mounting style, which seems like it doesn’t matter too much, but the Sundara Closed-back has a different on-head feeling for some reason. It feels almost like the pads are bigger than on the open-back version. To clarify, it’s a positive thing - they feel significantly more comfortable than the regular Sundara. I don’t know what exactly is affecting that, likely the new mounting style, but it’s definitely a step in the right direction.

Sound (Tonality)

Sound, especially the tonality, is the part I particularly dislike about this headphone. Unfortunately, I couldn’t find any reliable frequency responseA graph showing output amplitude vs. frequency - the most fundamental measurement of any audio component's tonal character. graphs, and I am not going to provide you with any that could be misleading.

Starting from the bass - it’s just fine, nothing special at this price point. There’s a significant amount of bass, it’s definitely present, but it lacks in terms of detail and isn’t particularly detailed. It doesn’t quite sound bloated though, which is a good thing after all.

The midrangeThe frequency range from approximately 250Hz to 5kHz where most musical information, vocals, and instrument fundamentals reside. is where most issues come from - that’s the main reason for my aversion towards this headphone. It comes across as extremely mid-forward, more than I’m used to, and I’m not the only one that has an issue with that. Folks at Custom CansAudiophile slang for headphones, particularly over-ear models. Originates from the metal "cans" that held early aviation and broadcast headphones., in the UK, figured out the cause of that mid-forwardness and found a solution. It’s caused by the damping foam, which is present behind the drivers. So they designed a kit “to reduce the hump in the mid-range on the Sundara closed backs.” They say that “If you are finding them a little too mid-forward, this kit may be the answer.” I’ve watched their video about this mod, including some frequency response graphs and sound tests, and I’m convinced.

The highs initially had a feel of a lack of detail. But after listening to these headphones for a while, as I always do with my evaluations, I think I know what’s going on. We’ll get back to that in the sound characteristics part. The high frequencies don’t have a lot of airiness to them, for sure. That makes them sound a bit darker than most HIFIMANs, which emphasizes the mid-forwardness even further. The treble extensionHow high in frequency a system accurately reproduces; good treble extension captures the fundamental and harmonics of cymbals and strings. is also unimpressive - there were times when I felt like I would like it to go just a little bit higher to achieve the desired amount of pleasure and fun with the song.

Sound Characteristics

HIFIMAN states that this Sundara Closed-back has a huge soundstageThe perceived three-dimensional acoustic space in a stereo recording - width beyond the speakers, depth front-to-back, and sometimes height information.. I cannot disagree with that - maybe it’s not huge, but still fairly large, especially for a closed-back. I was pleasantly surprised by that. However, it doesn’t sound very open. You can say that’s nothing unexpected for a closed-back design - however, there are headphones that sound much more open through the frequency range than the Sundara Closed-back.

Sound separation is at an acceptable level, nothing more. In some more crowded mixes, the sounds were slightly blending in with each other. That didn’t happen too often, but we’re not talking about a $100 pair of headphones at the end of the day - these are $229.

Detail Retrieval

That’s the part I was initially a little bit disappointed in, but then realized that this headphone is not aiming in the direction where it shouts at you with the micro-detailThe very lowest-level sonic information in a recording - the subtle sounds like breath, bow rosin, and room ambience that reveal what a system can truly resolve. - and if it is aiming for that, then it’s failing miserably. I believe that it focuses on letting you find most of the detail yourself rather than directly pointing it at you.

So the details are still there, but they’re simply not as easy to perceive. You need to be looking for all the minor details in the recording to notice them.

Dynamics

The dynamic rangeThe decibel span between a system's maximum undistorted output and its noise floor; 16-bit audio has ~96dB, 24-bit has ~144dB of theoretical range., including punchBass impact in the 60-150Hz region - the chest-thump of a kick drum or the snap of a slap-bass note. Distinct from slam, which extends lower; punch is about the leading edge of bass transients, not the depth. and slamThe visceral impact of low-frequency transients - kick drums, bass drops, tympani - felt as much as heard. High-slam systems combine deep extension with fast transient attack and high SPL capability without compression., is a pleasant surprise at this price. It can’t hit you as hard as let’s say an Edition XS, OG HE6, or most dynamic driverThe most common transducer type, using a voice coil in a magnetic gap to push a cone or dome diaphragm - the same principle as a traditional loudspeaker. headphones, but I didn’t feel like it was lacking in this department. Neither was I feeling like it was sounding sluggish or lacking in the decay. I usually correlate the lack of dynamics with the headphone sounding a bit boring - here it doesn’t take place.

Amplification

With an impedanceThe total opposition (resistance + reactance) a speaker or headphone presents to the driving current, measured in ohms and varying with frequency. of only 20 ohms and a high sensitivityThe output sound pressure level for a standardized input - typically dBSPL at 1W/1m for speakers, or dBSPL at 1mW or 1V for headphones. of 98dB, it’s extremely easy to drive. It’s not amp-picky at all, and basically everything can power it - even my phone. Going to a better source gear, there was a little improvement in the openness, detail retrieval, and soundstage.

Sound Isolation

As it’s a closed-back, I feel that this part may be important for some of you. Speaking about isolation of external sounds getting into your ears, it does a decent job at higher frequencies but gets worse as the frequency is getting lower. The effect of this is that everything that happens outside of the headphone sounds very bassy, lower-pitched, and muffled. Speaking of the isolation of the sound getting out of these headphones, it’s quite decent, all across the frequency range - not the best, but it does an okay job at that.

Conclusion

The Sundara Closed-back is an entirely different headphone compared to the open-back Sundara. It even has a driver that looks nothing like the one from the open-back Sundara. Moreover, the Sundara Closed-back somehow manages to be mediocre in every single aspect that I care about. It’s definitely not for me, but if these characteristics aren’t bothering you, then good for you.