The Hifiman Sundara Closed Back have been loaned to me directly by Hifiman for me to test them and share my opinions in this review. As always, they have not requested anything specific and I will do my best to remain unbiased and sincere in my review, however, it is always worth considering the fact that it has not cost me anything to try these headphones.
You can find the official page of the Hifiman Sundara Closed Back here: Headphones & portable audio - HIFIMAN.com
This is a non-affiliate link, as are all links that I share.
Before getting on with the review, l am going to do a little reminiscing…
I have a special place in my heart for the Hifiman Sundara, the original open back that is, as it was the first set of headphones I ever reviewed. Back in June 2019, before I had even thought about a blog or YouTube channel, I was included in a tour of the Sundara, with the agreement that I would publish my thoughts on Head-Fi after it concluded. I did so, publishing them also on forum.headphones.com, where they actually got published on the main headphones.com page.
Also around that time, I was looking for a set of closed back headphones, as I was sharing an office at the time and that meant could no longer opt for using speakers (which are still my favourite means of listening to music), and I really didn’t find anything that was in a decent budget range and that could live up to the quality of other similarly priced open back alternatives.
I have had chance to try a few higher end closed backs since then but I haven’t found anything that has made me want to run out and buy it at the price point it sits. My closed back option has been the Custom Studio Pro for quite a few years now, which is a decent set of headphones, at a decent price, but is by no means anything special.
All of this is to say that, when Hifiman released the Sundara Closed-Back version, I was very interested in getting to try it out, both due to the above and to see what Hifiman are capable of doing in the closed back space in comparison to their open back range (which I have been lucky enough to try out plenty of models, from budget to high end, and have quite a few on hand).
So, after that bit of a ramble, let’s talk about the real subject, the Hifiman Sundara Closed-Back.
Hifiman has changed their presentation recently, now optiong for plain brown cardboard boxes for most of their products, with a black strip that identifies the contents, in this case the Sundara CB of course.
Inside the box, the packaging has also changed. Instead of the silk covered foam inserts that were the standard for Hifiman, they now opt for a different foam without the silk lining. One of the things that I have to say about this new presentation is that the insert is shaped like a headphone stand and can be removed from the box and used for that exact purpose.
Personally I cannot store headphones on stands as I live in a place with a very high level of dust, so leaving a planar headphone (or any headphone for that matter) out of its box is a recipe for disaster. Therefore, all of my headphones live in their original boxes and in the case of this new presentation, I can grab the headphone and the temporary stand from the box, use it while I need it and then put it back. I feel it is a very useful way to make the most of the packaging.
Included with the headphones, we don’t get much. A standard 3.5mm cable, an 3.5mm to 6.35mm adapter and the usual documentation is the extent of it. As always, a storage case would be a positive but in my case, I just use the box so I am not complaining (although others would probably prefer a case of some sort).
Build and Aesthetics…
The Sundara Closed-Back opt for using wooden cups which I am quite fond of. It is nothing extravagant as far as wood goes, just a light coloured Beechwood, but it still gives them a premium feel. I don’t see any flaws or blemishes in the finish of the wood but even if there were some irregularities to the grain, that is what makes wood special.
One thing that I am extremely happy about is the choice of headband on this model. Now this is a very controversial topic as there are people in both camps, those who hate this headband and those that love it. The majority of Hifiman models lately are using the headband found on things like the Edition XS, whereas the Sundara CB opts for the one with the suspension strap.
The main difference is that this headband (on the Sundara CB) does not have any cup swivel, whereas the other headband (Edition XS) has swivel but no suspension strap. Personally I don’t miss the swivel as the headphones that use the suspension strap system just happen to fit me correctly without the need. However, the version with no strap does cause me a hotspot on the top of my head after a while. Sure, I would love to have swivel on this headband also but if I have to choose, I go with the suspension strap over the swivel. As I said, this is a controversial subject and everyone has their own preference.
As far as build quality, the only thing I have noticed on the set I have is that the right hand slider doesn’t click into place the same as the left slider does. It’s not really an issue, as the resitance is enough to keep it in place. For the rest, I really can’t say anything sticks out as an issue but only time will tell as always. There is a bit of driver flex when putting the headphones on but this is to be expected with closed back planar drivers, as they are so thin and there is nowhere for the air pressure to go. It is not noticeable in use, no matter how much I head bang
All tracks mentioned are clickable links that allow you to open the reference track in the streaming service of your choice (YouTube, Tidal, Spotify, etc.)
I have been using the Sundara Closed-Back for quite a while now, powering them from a selection of systems, however, my main use has either been in the office, powered by the iFi Gryphon, or at home powered by either the Hifiman EF400 or the Feliks Audio Echo Mk2 (fed by the EF400). I have to say that I was pleasantly surprised by how well the Gryphon powers these headphones even if I do personally prefer them connected to my home system.
I have also been using the Viking Weave cables with these headphones, I am not sying that it makes a sound difference but it sure does make them look great
Before getting into the description of the sound in my usual way, let me just say that, if you are thinking that the Sundara closed back is going to give you the usual Hifiman planar sound in a closed back, then I’m afraid that is not what we are getting here.
Now, that is not necessarily a bad thing, I am not saying it in a negative way, I am just trying to make it clear from the start that if you think that these are going to be an exact replica of the Sundara but in a closed version, that is not the case.
With that said, I am going to evaluate these headphones on their own strengths and weaknesses, not as a comparison to other Hifiman open models that I have on hand. I may drop in a reference here and there just for explanations sake, but a comparison is not something I believe to be useful as they are different headphones.
So starting off with the subbass, here we have the usual extension of the planar driver reaching way down into the lowest notes. The roll off of subbass frequencies starts around 35Hz and does drop quite quickly after that point but is well balanced down to that point.
Putting them through my usual test with “Chameleon”, there is no boost to these lower ranges but the clarity and lack of roll off makes the bottom end impressive. If you are someone that is looking for skull rattling rumble in the low end, then that is not what you can usually expect from planar drivers and the Sundara Closed-Back are no different. However, if you are looking for a clean representation of that subbass, then they will certainly give you that.
“Royals” by Lorde may actually be a more suitable track for these headphones as they give you that subbass presence without boosting it and actually present the track the way it is (in my opinion). In other words, that low end hit is clean but the following rumble is a little dirty, if that makes any sense.
Moving the focus onto the midbass region, with things like “No Sanctuary Here” or “Sun Is Shining”, the bass is clean, detailed and well balanced, without things sounding out of place. I find that many closed backs create to much of an emphasis on the midbass region, losing the control that I Iike so much with open back headphones, however, the Sundara CB does a good job of keeping it together and not pushing it too far.
I am still a big fan of a good dynamic driver for the bass regions, especially for bass guitar, and there are only a few planars that have really made me feel like I could live without a DD for some of those amazing bass performances. I think this is mainly due to the fact that, as a bass player, I have been so used to listening to my bass through dynamic driver cabinets that that is what I associate with correct. In the case of the Sundara Closed-Back, I can’t say that these have made me reconsider my preference for dynamic driver but they are a pleasant experience especially for those fast moving complicated bass lines, due to the speed and response.
If we take “Elephants On Ice Skates” as a sample from my playlist, I feel that the lower notes are missing a little “body and warmth”, leading to a timbre that I find a little cold and distant, yet there is no issue with keeping up with the speed of the bass in something like “The Room” by Ostura. The same could be said for things like “Whole Lotta Love”, where every bass note is clear and defined, yet the timbre is just a little “cold” in the low end.
Moving into the mids is where I have my reservations with the Sundara Closed-Back and this also ties in with the bass I just mentioned. As we move into the lower end of the mids, there is a bit of a bump that does restore a little of that body that I mentioned was missing in the bass, however, this can result overly exaggerated with certain tracks, more so because it seems there is a lack of mids in the center of the mid range.
I don’t have the equipment to measure over-ear headphones correctly, I only have the MiniDSP EARS and they are not the most reliable when it comes to measurements. Therefore I usually don’t bother measuring over ear headphones and depend on graphs from others such as Resolve (The Headphone Show) when I want a visual representation. However, it seems that the Sundara Closed-Back are not something that has been graphed by anyone I know at least that I can find. Therefore, as the EARS are “sort of accurate” in the midrange, being the part that can be trusted the most from the device, I decided to throw the Sundara CB on them to see why Iwas getting strange experiences in the mid range that varies from track to track.
Here is what the EARS showed me (this is an average of the 5 most repeatable measurements, although I took a lot more):
The reason that there are two lines is because I took the measurements in two ways, the blue line is with the headphones just placed on the EARS and the orange line is with slight pressure guaranteeing the seal. I have only posted the graph to really comment on the lower to central mids but thought I would show the full graph anyway, just don’t count on the shaded areas being a true representation of the actual headphone.
Anyways, back to the mids. As I mentioned (and as shown in the graph) there is a boost in the low mids followed by a dip shortly after. I have found that this interacts in strange ways depending on the track. There are songs where the instrument or even vocals don’t seem to be affected by that peak and dip, yet in other tracks, it can clearly make both instruments and vocals sound recessed or overly present, depending on just where they fall in the frequency range.
To give some examples from my usual test list, “Crazy” by Daniela Andrade sounds nicely balanced in the mid range during the main parts of the song, yet in the chorus, the vocals seem to take a step back and place themselves behind the guitar. This is something normal due to the nature of the song but the Sundara CB does seem to exaggerate this.
“Hallelujah” is an acapella track with many voices and this song actually exhibits behavior that depends upon the voice. Here the main male vocal is actually more recessed than the backing vocals, missing some presence in the lower parts of his range, whereas the female vocal takes a step forwards and places itself in front of the backing vocals.
Moving to something more electronic, such as “Light Years Away”, here the effect is a lot less noticeable and, if anything, it actually works in favour of the track. That boost where the midbass moves into the lower mids actually makes this track very punchy, which, added to the detail, makes for a very enjoyable listen.
One last track before moving on is “Killing In The Name”. The guitar here does suffer slightly from some imbalance in their lower ranges. It is not necessarily bad but it is different to what I come to expect from this song. Zack De La Rocha’s voice does take a little step back, with the lower end of said guitar becoming a little blunt, missing a bit of presence in the center of the mids for my preference.
Moving on to the upper mids, here we have the typical Hifiman dip that is something that has never really bothered me too much, putting a bit more emphasis on that 3kHz mark which is good because it does go a long way to clean up the sound. I feel that if the 3 to 4kHZ range wasn’t as present, then we would be looking at a very dull sounding set of headphones in the midrange.
Moving up into the higher ranges, there is a nice extension which I have come to expect from planar drivers but there is a little bit of “sizzle” in the highest ranges. This is not to be confusd with sibilance as sibilance is controlled well, with Patricia Barber being very listenable in the usual “Code Cool” test. Although “Code Cool” is another track that does suffer a little with that mid range imbalance.
Details and speed are something I certainly cant complain about. The Sundara Closed-Back deliver the amount of detail that I have come to enjoy (and expect) from Hifiman planars. However, once more, that mid range does take away the sensation of detail in those ranges, especially on the lower ranges of electric guitars and vocals that have their roots located in that dip. This gives the sensation of those ranges being blunt and lacking details, however, it is more that they are masked behind that boost that precedes them.
I am going to repeat what I said at the beggining of the sound section. The Sundara Closed Back are not a headphone with the typical Hifiman “house sound”.
As some of you probably know by now, I am a big fan of the Hifiman sound and I have quite a few models on hand, from the budget HE400se up to the Arya or HE1000se, with quite a few in between. Although there are clear differences between the different models of the Hifiman line, there are also a lot of similarities, making all of them clearly Hifiman in their overall sound.
The Sundara Closed Back breaks away from that usual house sound and give something that is very different in the mid range. Because something is different, doesn’t mean it is bad, there are lots of songs that I have enjoyed very much on the Sundara CB but there are also lots of tracks that I haven’t enjoyed, finding that the variation in the lower mids has a negative effect on how I expect the song to be presented.
Again, I am by no means saying that the Hifiman Sundara Closed Back are a bad set of headphones, just that they are a “different” set of headphones. Usually, if you have tried something from the Hifiman line and like the sound, you can relate to other models that will improve on certain aspects but will, in general, sound similar, giving you a good reference point. With the Sundara Closed Back, that is not the case.
I would certainly urge anyone looking into the Sundara Closed Back, whether they have had previous experience with Hifiman or not, to give them a listen and find out whether they work for you or not. If you are someone who uses EQ, then I don’t think you need to worry as the drivers always respond well to EQ, but if you are someone who just plugs in and goes, then you may or may not like these headphones, depending both on your personal tastes and, more than ever, on the music you listen to.
As always, this review is also available in Spanish both on my blog (www.achoreviews.com) and on YouTube (www.youtube.com/achoreviews)