HiFiMAN HE6se Open-back Headphones Review

By : Theo @ Samma3a

Samma3a Tech Rating 8

What Rating Means ?


  • ● Reasonably wide sound stage
  • ● Good instrument separation and overall frequency response
  • ● Comfort is relatively good


  • ● Extremely power-hungry
  • ● Minor build quality issues

Bottom Line

If you do already have a headphone amp that can provide adequate power, then the HE6se offers a very respectable sound character, and so could well prove to be a healthy upgrade over something like the Ananda, and perhaps even the Edition X V2










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Sound Quality









  • Frequency response: 8 – 65kHz
  • Sensitivity: 83.5 dB
  • Impedance: 50-ohm
  • Weight: 470g


he6se-boxThe packaging for the HE6se is rather typical of what we’ve come to expect form HiFiMAN as it follows the same theme as that of the vast majority of their other headphones.
The large box comes wrapped in a faux leather texture and some contrast stitching. on the inside we get the familiar satin material giving the presentation a a real sense of luxury.he6se-open-box


Not a whole bunch is included with the HE6se other than the cable and a short ¼-inch adapter cable. The feeling of the cable is typical of other HiFiMAN cables in the sense that it feels a bit rubbery. he6se-box-contentsI’m personally not a fan as they just don’t exude that premium feeling that I’d want at this price-point. The storage case is pretty much identical to what you get with the majority of HiFiMAN’s other headphones.


The overall design of the HE6se looks very similar to that of the Sundara, The only thing we see that’s been carried over from the original HE6 is the mesh design of the grill, whereas the grill on the Sundara has more of a chain-link design.he6se-side-2The other notable difference is with regards to the weight. Whilst the HE6se is 32g lighter than the original HE6, it’s still nearly 100g heavier than the Sundara. This means that you have to size it just right in order to avoid having all the weight centred on the headband which would subsequently create a hotspot during longer listening sessions.
The headband does create a bit more clamping force than what I would like, though, but of course, your mileage might vary. If I were to purchase these for myself I would perhaps stretch it out just a bit to give me a little more comfort.
The only place where we can see that plastic has been used is where the headband adjustment system meets the rest of the spring-steel headband. he6se-text-2I do feel that, given the substantial price-gap between the Sundara and the HE6se, HiFiMAN really should’ve done something more premium here.  There is a little bit of creaking when slightly twisting the cups, but I won’t say that it feels cheap to me. But still, there surely could’ve been a more premium approach to this part.
The only other area of slight concern for me is with the grill. As we can see, we can move them about. Now, they don’t rattle around if you shake the headphones, but I can’t help but wonder if they might introduce some slight rattling when playing music. Perhaps not so much that you’d be able to pin-point the issue, but perhaps just enough to have a slight effect. Who knows?


One of the downsides to an open-back design is that, because your ears aren’t isolated from the outside, not all of the sound energy is directed towards the listener. As a result, what you’ll find is that an open-back set of cans will require more power to get to the same volume as a closed-back set of headphones with equivalent impedance and sensitivity.
So, if we look at the specifications we’ll see that the HE6se has the same listed specifications of 50-ohm impedance and efficiency of 83.5dB/V as the original HE6.
That impedance of 50-ohm really isn’t very high, so at first glance you might think that the HE6se would be pretty easy to drive, but the more important figure is the sensitivity. Unfortunately, it seems that manufacturers simply can’t make up their minds with regards to whether to list sensitivity or efficiency figures. For the most part, headphones and IEMs are usually listed with a dB/mW figure, whereas HiFiMAN provides a dB/V figure for the HE6se. It’s perhaps even possible that they did this intentionally to make it seem like the HE6se is easier to drive than what it actually is, and they did the same thing for the original HE6 too.
Now, often we’ll see people quoting impedance figures as some sort of indication of how hard a particular set of headphones will be to drive. However, in reality, the impedance figure doesn’t actually tell you much on its own.
For example, we can easily work out that a headphone that has an impedance of 2000-ohms and rated at 86.5dB/mW would require the same of mount of power, to get to a certain volume level, as what would be required by the 50-ohm impedance and 70.5dB/mW of the HE6se. So, is impedance important? Sure it is, but it’s not as indicative of the power requirements as the sensitivity or efficiency figures.
So, when we consider the open-back design along with the low sensitivity of the drivers, we can see that the HE6se would indeed require a pretty substantial amount of driving power. In fact, HiFiMAN recommends that you use an amplifier of at least 2W per channel.
I found this to be quite spot on as I had to run the HE6se on my Micro iDSD Black Label on its Normal power setting which is capable of delivering up to 1.9W, and for some music I did turn the volume pot all the way up. But really, where it sounded like I had hit the sweet-spot was when putting the Black Label in its Turbo power setting. This is capable of producing quite a bit more power than what would be needed by the HE6se, but it sometimes proved quite useful in making the HiFiMAN sound its best.

As you might expect, the HE6se does have a removable cable design and it uses a 3.5mm connection for each channel.
If you’re a fan of XLR connection you’ll be happy to know that the cable is terminated with an XLR connection, but we also do get an adapter to convert it to a more common ¼-inch single-ended connection. Unfortunately, this means that you would need yet another adapter if you wanted to use the HE6se with a source device that has a regular 3.5mm output, but given just how power-hungry these cans are the chances are that all of the amps that have enough juice to throw at the HE6se will have a ¼-inch connection anyways.


In terms of the sound, the HE6se follows what has become a pretty typical HiFiMAN signature, and judging from the fact that the impedance and sensitivity specifications are the same as for the original HE6, there’s a good chance that it’ll sound pretty similar to the original too. Although, this is not something I can really state as a fact since I’ve neither listened to nor had the chance to measure the original HE6. he6se-responseWhat we get is a pretty flat response between the bass and sub-bass region with a slightly elevated presence in the mids. There’s a steady climb from around 2kHz up to a sharp peak at 4kHz. This peak can sometimes be a little bothersome, and I found this to be particularly true when listening to Daft Punk’s Doin’ It Right where the clap sounds came across just a bit too forward and distracting for my tastes. When I lowered this region within the EQ it became less bothersome. But then again, this isn’t something that I can say that I constantly found to be bothersome, so I wouldn’t count it as an inherent flaw.
Also, our brains have an amazing ability to adapt to things, and so if your current headphones also tend to be a little mid forward, then there’s a good chance that your brain would’ve “filtered out” that characteristic, in which case that upper mid-range spike of the HE6se will probably go unnoticed to you.

Further along the frequency response we have a few more dips and spikes but nothing in particular that stands out as being problematic to me. That slight spike at 10kHz does seem to help give a bit more shimmer to cymbals which is quite pleasant.

I did notice that the HE6se didn’t sound quite as wide as I had anticipated. But this might be partly due to the fact that I was also reviewing the HE1000se, so that might’ve had an influence here. But the depth sounded pretty good to me, as did instrument separation within the sound field. It’s still wider than regular closed-back headphones anyways.

Overall the HE6se offers an agreeable sound signature, provided of course that you’ve got an amp that can throw enough power at it.


Judging the value of the HE6se is pretty much going to depend on what other equipment you have. Honestly, if your headphone amp isn’t capable of delivering more than 2W of power to these cans, then you’ll really be wasting your time. There are very few headphones that require me to switch my iDSD Black Label into Turbo power mode, but the HE6se absolutely demanded it, and even then I had to turn the volume-knob all the way to the two o’clock position.he6se-earcupsSo, what this means is that, if you don’t have a particularly powerful amp, then you might end up needing to factor in the additional cost of an appropriate amp as well if you do decide on getting the HE6se. This just is an unfortunate but nevertheless inevitable side-effect of using ultra-low sensitivity headphones.
But, if you do already have a headphone amp that can provide adequate power, then I think the HE6se offers a very respectable sound character, and so could well prove to be a healthy upgrade over something like the Ananda, and perhaps even the Edition X V2.



HiFiMAN HE6se Open-back Headphones Review

Samma3a Tech Rating 8