I just posted over on HF my detailed impressions on the Hifiman Sundara after having had them for a little over 2 weeks on loan. I also want to share those impressions here.
I didn’t find a specific Sundara thread and it seems the title “Hifiman Sundara” has already been used (in the Deals section I believe) which is why I added the “Review” part to the title, but please move it to the correct thread if I missed it or there is somewhere more relevant for this post.
Disclaimer:
This set of headphones was kindly sent to me by Hifiman as part of the Sundara loaner tour. I have been able to test these for a little over two weeks (they allowed me a few extra days for burn in due to the unit being new). Hifiman requested that I posted on Head-fi my initial impressions upon receiving them and more detailed impressions after spending a couple of weeks with them. No other requests were made in exchange for the loan.
About me and the set up used
While I am still new in the headphone world, I have been working in the pro audio world for around 25 years. My experiences range from performing on stage, stage monitor mixing, FOH mixing, studio recording, live concert set ups and permanent live venue audio installs.
My main (over-ear) headphones are the Beyerdynamic DT1990 and the Sennheiser HD6XX, the majority of comparisons in this review have been made against the DT1990 due to their similarity in price range but also the fact that I use the DT1990 for most mixing and production purposes (music production).
I have been listening to the headphones using either the SMSL SU-8 or the Topping D10 DACs, feeding the JDS Labs Atom or Loxjie P20 amplifiers. I have also used the Sundara powered by the Topping NX4 DSD. However, all detailed comparisons and opinions have been made while using the Topping D10 into the JDS Labs Atom.
The tracks used for testing this unit have been both FLAC and Spotify 320kbps. The majority of detailed listening has been with FLAC files whereas lot’s of listening time spent in my office is with Spotify.
Unboxing and First Impressions
Upon receiving the box, directly from China, I opened a plain cardboard box to find the Sundara product box inside.
The headphones themselves are packed surrounded by what feels like a styrofoam type cut-out covered in a silky type material. In the center of the box there is a space for the cable.
While the packaging is sufficient, it does not scream high quality but that means more money has been dedicated to the unit and not the packaging, or at least I hope so!
The cable included is a stiff rubbery cable which is 1.5m long. The cable is terminated with a 90º 3.5mm connector at one end (with a 3.5mm to ¼” adapter included) and two straight 3.5mm connectors at the headphone end, one for each cup, clearly labelled L and R. I must say that I am not overly impressed with the cable. While it seems to be of decent enough quality, the rubbery feel and the stiffness are just not something that appeals to me.
The fact that they have opted for a 3.5mm connection on each cup is highly appreciated as it means that making a balanced cable for these headphones is not difficult and doesn’t include purchasing some kind of proprietary connectors.
There is nothing else included in the box and while I did say that I would rather them spend money on the product than the packaging, some kind of simple carrying bag would have been nice.
Build quality
As mentioned above, I have spent time comparing these to the DT1990 which is of amazing build quality, so the Sundara were facing some tough competition from the start. Having said that, upon inspection, the build quality of the Sundara seems to be pretty good. These are my first pair of Hifiman headphones so I can’t compare them to other models but they do look to be well put together.
A small issue I find is with the metal cup holder that is connected connected via the plastic part (the part with the logo) that offers adjustment. Other than it having a little bit of slack allowing it to rock slightly backwards and forwards, the adjustment is also quite stiff. This may slacken over time but it causes the paint to rub and leave marks when adjustments are made, it also makes it difficult to adjust them when they are on your head as both hands are needed. This is only a minor issue but it is worth noting.
Comfort
I have found the Sundara to be very comfortable, even for long listening periods (5 and 6 hours). Once the headband was adjusted and placed on my head I felt no need to make any adjustments or move them. I find the pads to be very comfortable, more so than the Beyerdynamic or Sennheiser pads which cause me to itch after a while, and although the opening is of a very similar size to the DT1990, it seems that the type of material (some kind of perforated imitation leather) on the inside of the pads does not cause the sensation of rubbing on my ears.
My head is rather large and I wear the Sundara on the 4th setting with another 2 positions available before being fully open. When placing the headphones on P (my headphone modelling assistant 
) the fully closed position is still a little large for her small head.
Power
I had no issue powering the Sundara from the Atom, the P20 or from the Topping NX4 DSD. I do not listen to music at very high levels anyway (I learned my lesson over the years) but I found that 50% on low gain of the Atom was more than enough for my listening preferences (for 90% of songs). With the volume at 50% on high gain of the Atom it was too loud for my personal comfort. Obviously everyone has different preferences for listening levels but I don’t think anyone will have issues powering this with any semi decent amplifier. I did try these using my phone (Xiaomi Note 4) and my Shanling M0 and while they did reach volume levels that were acceptable, they didn’t offer the power needed to get the clarity and detail that these headphones offer.
Sound
While I have taken measurements with the MiniDSP EARS, I have not posted any previous measurements of any headphones and as this is not an industry standard device, nor is it consistent from one unit to the next, I am not going to post these measurements because you do not have anything relevant to compare them to. I am afraid that you are going to have to put up with my subjective opinions only!
(Note: My hearing test this year, the official test for work health purposes, reflected that I can hear just over 18kHz but it did not conclude that I am good at it! )
My first impression of the Sundara was that it was much more laid back than the DT1990 and actually lacked the clarity of the Beyers. However, after acclimatizing to the Sundara (or maybe it was burn in) before going back and forth between them, I realized that my initial impression was wrong and that the Sundara do not lack that clarity at all. In fact, after two weeks of constant listening between the sets, I feel that the Sundara has the same clarity but presented in a different way.
BASS : This is my first time with a planar-magnetic headphone so I have no previous experiences on which to “base the bass” other than what I expected from having read about them. Based on these preconceived expectations I thought it would have more in the sub-bass region. I am not saying that there is a lack of bass, far from it, but when listening to certain hip hop or EDM tracks, I feel that the bass is not quite as present as on other headphones.
This is not a negative point for me as I am a bass player but not a bass head and I will say that for tracks that include bass guitars, rather than electronically created bass lines, the detail in the low regions is amazing. I have enjoyed listening to recordings of my own bass lines and being able to pick out nuances that are not present 90% of the times that these tracks are played back on various systems.
An example of what I am trying to say about bass quantity would be “2Pac - Ambitionz Az A Ridah”. The recording of this has a rather big bass boost around the 40Hz region. On the Sundara, rather than sounding bass heavy, the bass just sounds clean and clear.
Another example could be “Billie Eilish - Bury A Friend”, this track has plenty of subbass that is not that present on the Sundara. This actually makes the track sound better (in my opinion) but is certainly not what I expected. If we take it to the extreme, the track “No Mercy” by Gustavo Santaolalla (from the OST of the game “The Last Of Us Vol 2”) is highly dependent on subbass which is not present in the Sundara, at least to the levels needed for this track.
MIDS: I find the mids to be very smooth and detailed, however, the voicing of the mids seems to be better at resolving female vocals than male. During the 8 hours a day I spend at my desk, a lot of that time is spent listening to acoustic and vocal music as it helps me concentrate more than other kinds of music. These tracks I would say are 80% female vocals and 20% male. The female vocals sound great but I find the male vocals to be slightly recessed. This is not as noticeable when the track contains purely male vocals but when there is a combination of the two, the female voice seems to be more present and forward than the male.
“The Civil Wars - Billie Jean” is a good representation of this, the female voice seems to hog the spotlight in comparison to the male voice.
Again though, the detail is very present, allowing you to pick up on all kinds of nuances such as breathing or even licking of lips, things that are usually only spotted in the studio while listening to isolated tracks, an example of this would be Lana Del Rey’s voice during the song “Hope Is a Dangerous Thing”, you can also pinpoint where her vocals are muted (at 1:26) to leave just the instruments. The same goes for instruments but to an even greater degree, the sound of string noise actually can give you an impression of how an acoustic guitar is being played such as with “Fink - Trouble’s What You’re In (Live From Union Chapel)”.
An example of the detail even though recessed would be “Busta Rhymes feat. Lenny Kravitz - Make Noise” (from the Anarchy album), in the recording of this song, the voice of Busta Rhymes is far more recessed than the backing vocals or the guitar played by Kravitz. The Sundara actually make his voice sound even more recessed but at the same time manage to provide more details than other headphones where it is less recessed.
TREBLE: As I mentioned in the “About Me” part at the beginning, I have worked far more with monitors than headphones and my favourite studio monitors are Genelecs which are very good at high frequencies across most of their models. I have found that the DT1990 can imitate those Genelec highs pretty well but can be a little harsh if not controlled, I have the same results with Meyer Sound, they are excellent but can become harsh if not controlled properly in the higher regions. I find that the Sundara are far more forgiving in this respect, they have not seemed harsh at any moment without sacrificing any of the details needed to be clear in the upper regions. This was particularly clear in certain classical pieces where violins and other high pitched instruments could be 100% present and forward without seeming harsh at any time.
There is no harshness at the 8kHz like on the DT1990, for example, “Queen - Don’t Stop Me Now” (from the remastered “Jazz” Album) is much more enjoyable on the Sundara where it can become very harsh on the DT1990. Another good example, although slightly lower than 8kHz, would be “Enya - Only Time”, the “s” of the lyrics when she sings “Who can say…” can be very sibilant on the Beyer whereas the Hifiman remove this issue.
IMAGING, SOUNDSTAGE AND OTHER DETAILS: I know I have mentioned detail in each of the three sound frequency groups above but it is something that really stands out to me, along with the speed at which this headphone can resolve even the most complex and busy parts of songs. For example, while listening to “Metallica - Master Of Puppets” the instruments remain clear and separated between themselves, allowing you to notice even how the cymbal crash decays to the left channel as it fades away. “Pigbag - Papa’s got a brand new pig” is another very busy track where the instruments can easily get lost with each other, the Sundara keeps these separate and also avoids, to some extent, the harshness of this track that can become unbearable on the DT1990’s (note that this track is unbearable on most systems I listen to it on, which is why I like testing with it).
The soundstage is not extremely wide, or at least that is the impression I get, but it does seem to be much wider than the HD6XX for example. The imaging, however, is excellent. In the case of the track “Yosi Horikawa - Letter” you can pinpoint the exact spot of the pencil at all times although it doesn’t seem to extend as far left and right as other headphones.
Conclusion and closure
Around 6 weeks ago there was a promotion on the Sundara and they were selling for 30% off and I was very tempted to purchase them. Finally, I ended up not pulling the trigger as I had never heard a planar magnetic nor a Hifiman product before. Now that I have had a chance to try these I do regret that decision.
I think these headphones are perfect for sitting back and listening to music. They are not aimed at those who are looking for a huge amount of bass, rather at those that are looking for enjoyment without any loss of detail.
After this time spent with the Hifiman Sundara, I am seriously contemplating putting the Sundara on my purchase list as they offer a sound quality that I have really enjoyed. I am also very interested in trying out one of their higher models to see what that step up brings, although it is difficult to get to listen to headphones here before you purchase. For this reason I am very grateful to Hifiman for allowing me the time to test these.