The reviewed headphones are among the most expensive models offered by the American company HiFiMAN. The HE-6 (‘HE’ in the name is the name of their designer, Mr. He, a born Chinese) is the newest addition at the top, while the HE-500 are positioned between the old “flag” model EL-5LE and the HE-6.
The latter are a classic evolvement of the previous design – they have rather low impedance (among headphones only the Grado have a lower one) and, most of all, very low efficiency. This makes them very difficult to drive – they require a very powerful amplifier.
On the other hand, the HE-500s were designed to work with a wide range of headphone amplifiers. Not much is known about their construction, except that they are planar, magnetostatic (orthodynamic) headphones. It is really hard to learn anything about them. Srajan Ebaen, who tested them earlier, had the same problems. Fortunately he managed to pull out some information from Mr. Fang: “The HE-500 uses a more complicated array of bigger magnets to increase sensitivity over the HE-5LE plus a different diaphragm to improve midrange performance. Sensitivity is 89dB, impedance 38Ω. Our portable players can drive it well. The magnetics are actually the HE-6's. The diaphragm was modified to provide better vocals and bass. The voice coil traces are coiled aluminum, not gold. Then we apply a different treatment to the surface of the HE-500's diaphragm. That makes it different from our HE-5, HE-5LE and HE-4 models. The HE-500 is better than the HE-5LE in almost every way. While the HE-500 lacks the HE-6's ultra clarity, its sonic signature over a regular headphone amplifier is pretty close to that of the HE-6 over a high-end amp.” (Srajan Ebaen, HiFiMAN HE-500, 32Ohm Series, Chapter 37, „6moons.com”, May 2011, review HERE)

Looking at the HE-500 and other headphones of this manufacturer, letting aside the different color of the metal components in the newest HE-400 and HE-300, it is hard to catch the differences between them. They are headphones with soft shells surrounding the ears. The reviewed units have their soft parts made of a soft material (velour). The headband is also the support point on the head – it is covered with leather in that place. From below each earcup we see a detachable cable. The sockets are very good – gold plated, with Teflon used as isolator.
With each model we get a different cable; for the HE-6 it is balanced, with an adapter to an unbalanced 6.3mm “big jack” plug. The cable is made of high purity (single crystal) copper. The adapter is very heavy and located quite uncomfortably – the whole time I had problems placing the cable in such a way that the adapter would not pull it away.
The HE-500 comes with a thick, rather cumbersome cable from the Japanese company Canare, originally designed as a speaker cable (3m length). However, in the set we get another, thinner cable, terminated with a 3.5mm mini-jack, but with four rings. It looks almost the same as a standard mini-jack, but has separated ground for the left and right channels, for Mr. Fang believes in superiority of balanced connection of the headphones. Usually, a stereo cable with a jack plug has common ground for both channels; here it is separated. Of course, you need a special amplifier, with a dedicated socket – HiFiMAN has a suitable model in their catalog – the EF-6, also an optional amplifier card to the HM-801 player, with a balanced output. In the box we also have a spare earpads and spare sockets – to be able to use any cables.
All big HiFiMAN headphones have orthodynamic design, also called planar-magnetic – they are magnetostats (similar to loudspeakers from Magnepan). Their diaphragm is made of ultra-thin Mylar foil with the voice coils sprayed on it. According to Mr. Fang, the HE-500’s coils are made of aluminum, and the HE-6’s of gold. The magnets in such constructions can be placed on one side of the diaphragm or on both sides. In the HE-500 and HE-6 they are on both sides.
The HE-6s are nicer on the outside – it can be seen that the company went to great lengths to make them look more luxurious: shiny metal components, nicer leather, etc. Except for this, both models look identical and come in very similar boxes. The biggest difference is their effectiveness – HE-500s have 89dB (1W/1m) and the HE-6s 83.5dB (1W/1m).
The headphones fit well on the head, although they seem heavier than the HD-800 from Sennheiser. But they clamp on harder and maybe that’s why their bass seems more energetic.

SOUND

HE-500 + Leben CS-300 SX [Custom Version]
I started the listening session from the comparison of the HE-500 to my headphone system, meaning the modified amplifier from Leben and the Sennheiser HD-800 headphones. In my opinion this is a killer combination. Many times I cannot wait to sit down in the evening, with a book in my hand and headphones on my head to listen to something new, or something I know very well. It is not easy to compete with such a duo, and to date nothing came even close, including my beloved and valued AKG K701 headphones. The only breach in this wall was the system from STAX. But only in a few aspects. And if I had to choose, I would take my own system without a hesitation.

Placed in such a hostile environment (mentally, not electrically…) the HiFiMAN headphones showed what the Sennheisers are lacking, presenting a slightly different, alternative world (I mean, they made me realize its existence), but also paid a tribute to the HD-800.
Let’s start with the things that Fang Bian’s headphones do better. The HE-500s sound less “clumped”. I do not know how to describe it differently, but probably do not need to – this description is quite fitting for the impression we have going from the HE-500 to the HD-800. It is a little bit different the other way round, but that’s not the point. The American (although manufactured in China) headphones can put things together better, glue things together from loose elements. In contrast to “clumping”, “gluing together” is here a purposeful process, having greater good as its goal, while “clumping” is something chaotic and pointless.
Due to all this, the sound of these headphones is very coherent. The Sennheisers seem sloppier in comparison. And there must be something to it, for although after long listening sessions, after accommodation of the ears we have to modify this opinion a little (based on the same premises!), yet this first impression brings valuable information.
We can also immediately hear that the tonal balance of the HE-500 is completely different. Their midrange is clearer, much more open. This is especially well audible with vocals – either listening to Ego:X by Diary of Dreams or to the duo Fitzgerald and Armstrong, the impression of their presence, here and now, was much more unanimous.
Interestingly, with instruments that should profit from that, such as the vibraphone on The European Concert. Volume One + Volume Two by The Modern Jazz Quartet, or the acoustic guitar of Ralf Illenberger, the Sennheisers had an advantage, giving both instruments more energy, better defining their body. Why it was that way – I do not know. Maybe it was a reflection of matching the headphones with the given amplifier.
The bass reaches similarly low in both headphones, although the HE-500s show it in a more coherent way, clearer reproducing the moment of energetic sustain (because they are not sharp, so the attack is not accented). However, the Sennheisers fill it with content, in the sense that the flow of the melodic line is better with them.
A similar thing happens to the treble. The HiFiMAN headphones seem a bit closed at the top, not bright enough. Against such background, the HD-800s seem much more open, better differentiating the upper treble components.
In general, these are two completely different pair of headphones. The HE-500s play the midrange and upper midrange stronger, also the bass, while the treble is softer. Putting them on our heads we go somewhere else – the sound is very energetic and exciting. However, since this happens every time, the emotional tension is not differentiated between recordings.

I was curious, how well the Leben can control bass in the American headphones. It turned out that it had absolutely no problems. The bass was energetic, and I did not have the impression that it loses control even with the very low passages on the Diary of Dreams CD, or much more saturated but longer sounds on the CD by Pieter Nooten and Michael Brook. 7W in class A, in push-pull setting is absolutely enough to drive these headphones in a satisfactory way. The volume knob had to be set past half scale, but for me this is not a problem.

HE-6 + Leben CS-300 SX [Custom Version]
The HE-6 confirm what I heard with the HE-500, and earlier with the HR-4: the HiFiMAN headphones are incredibly resolving. Electrostatic headphones have a similar sound (I am thinking about the STAX and the Sennheiser Orpheus, which I could listen to a few times), but only the newest systems of the first manufacturer can approach, although not completely, the fleshiness of the sound offered by dynamic headphones and – yes – the HiFiMAN. The latter combine in one place incredible resolution and very nice fleshiness. And their ability to differentiate, segregate and show something that is close to the studio or stage reality is absolutely incredible.
With all this the HE-6s are even clearer than the HE-500s and have their tonal balance set much closer to what the Sennheisers show. There is no cutting in the upper treble and no accenting of the upper midrange. The bass seems a bit lighter than in the HE-500s, but seems to be better joined with the rest of the frequency spectrum. The HE-500s were brilliant, very universal and spectacular. The HE-6s are much more refined.
Their problem turned out to be their cooperation with the Leben. The Japanese amplifier could not power them up to high volume levels; it would lose control over the bass and enter into clipping. At medium volume levels, i.e. when everything was audible but it was not very loud, everything was OK. But sometimes, like with Diary of Dreams, when we need to pump up the volume because that’s what the music is all about, the Leben just could not do that.
Anyway, the voices of Fitzgerald and Armstrong, his trumpet and Illenberger’s guitar – everything was clear, coherent, and absolutely not sharpened. This was not a “thin” sound, the HiFiMAN headphones sound in a full, saturated, and very coherent way. At the same time they are very energetic, which probably comes from the fact that they have lots of information to convey, and they are not afraid to do it…
But the most important message in this fragment of my review is that not-so-powerful amplifiers will not handle the HE-6 at all. We need to use something much more powerful than my Leben – equally refined, but handling such a demanding load. I will return to this information later.

HE-500, HE-6 + Synergy HiFi APPJ PA0901A
This is a very good combination (I wrote about this Chinese amplifier in the editorial to the October issue: Little Dreams, “High Fidelity”, No. 90, November 2011, HERE). Despite its moderate power and with a single tube per channel (EL84, class A, SE) the amplifier handled the HE-500 easily. This combination was not as refined as with the Leben, but taking into account the price of this combination – it sounded surprisingly well. This amplifier showed that the treble in the HE-500 are less pronounced than in the HD-800. Maybe it was caused by the amplifier itself, which reacted differently to the more demanding load posed by the HiFiMAN headphones, but that is how it sounded. Still, the incredible directness of the sound, its palpability remained. Everything was closer than with the Sennheisers, at arm length. But… Maybe that is a paradox, but such is audio, full of paradoxes – the headphones from USA showed everything more focused, deeper than the Sennheisers. There is no wide perspective, as with the latter headphones.
On the other hand, the HE-6s show the events a little bit closer than the Sennheisers, in the sense that the stage is bigger than in the HE-500, the instruments are closer than in the HD-800, but the performers are grouped more in the front than to the sides.
The Chinese amplifier drove the HE-6 quite nicely – because this amplifier has a lighter sound than the Leben, it does not go that low, so there is no reason to clip… But it worked best with the HE-500 and the Sennheiser HD-800. The HE-6s from HiFiMAN require a more refined amplifier. But the HE-500s, also splendid, sounded very nice.
The Synergy HiFi amplifier does not have a headphone output, only loudspeaker outputs. Especially for this model the company prepared a kind of adapter – a flat, metal box with banana plug inputs (to connect to loudspeaker outputs of the amplifier) and three headphone outputs – one mini-jack 3.5mm and two big-jacks 6.3mm. It is called APPJ HP A.

HE-500, HE-6 + HM-801
The listening session with the HM-801 player, equipped with a current efficient, fantastic headphone amplifier (an exchangeable module; the company made the schematics accessible – everybody can design their own version!!!) showed both headphones from yet another side. As with previous listening sessions, this comes with the provision that, again, the HE-500 could be driven without problems, while the HE-6 not fully. Now it was more precisely audible that the HE-500s are much darker than the HE-6s. The tonal balance of the latter reminds me more what I know from the Sennheiser HD-800. But the HM-801 and the HE-500 is something special, a beefed-up, exceptional high-end on your head. I have been listening to this combination for a long time and each new hi-res album bought on the Internet brings another portion of joy. Rumours by Fleetwood Mac, Metallica (obvious), Miles Davis’s Tutu, and others (all 24/96; unfortunately the HiFiMAN does not play 24/192 and 24/88.2 files – pity) – all sounded at least very good. Even more commercial recordings, such as Touch by Yello, created an adrenaline shot in my blood…
The same recordings did not sound equally exciting with the HE-6s. Firstly because they would need a bit more power, but secondly because these headphones need something even more resolving.

Summary
The HiFiMAN headphones are different than anything else around. They also sound different. Their sound is incredibly resolved. But it is not as thin as with most electrostatic headphones – there is flesh, bass, attack, fullness. There is also smoothness. But they need headphone amps that meet the basic requirement of high or very high current efficiency. I think mostly about the HE-6s, which simply do not play with a power lower than a dozen watts. This is why I consider their review as a first step, an open project. Even the HF-5 amplifier from HiFiMAN could not fully show their abilities. You could hear their potential, but not completely utilized. I must listen to them with the new HiFiMAN EF-6 amplifier and the Cary Audio SLI-80 tube amp.
Preparing for this review (like each project, each review requires getting acquainted with the company materials, available reviews, correspondence with the manufacturer, etc.) I read the HE-500 and the HE-6 reviews made by Srajan, which I even mentioned in the beginning. In his review of the HE-6 he mentioned one combination that – despite the low price of the amplifier – turned out to be the right one. It is the Ampino amplifier from the Serbian company Dayens. And this is another proof that there are no coincidences – that particular amplifier has been at my home from three months, waiting for a free review slot. It is distributed by Marcin Ostapowicz, the co-author of JPLAY software player. He is doing it as a hobby. Yes, this was a nice combination. Finally there was no problem with power. I’ll just add that it was also audible that it’s not a very expensive amplifier. And that it is better to combine the HE-500 with a classic headphone amplifier.
For the HE-500s are much easier to power, but they have a different timbre – there is less treble, and the midrange, especially its upper part, is stronger. It does not work well with each amplifier. It turns out that – in my opinion – the HE-5 and the HM-801 were designed especially for these headphones. Together they sound exceptional!
I did not mention cables in this test. According to Srajan Ebaen, changing them brings a significant change to the sound. I already ordered cables from EntreQ. When they arrive I will return to the case.

Would I exchange my Sennheiser HD-800 for any of the HiFiMAN headphones? No, I would not. With the Leben amplifier the HD-800 is an exceptional combination (the only issue is the audible hum of the amplifier). I would not exchange it for the HE-6/HE-500 simply because now I know that I MUST have a dedicated second system, only for the HiFiMAN headphones. I am trying to minimize the amount of boxes in my system, I am trying to simplify, but only to the point where it makes sense. Here – there is no alternative to this alternative, so to say.
The headphones from Mr. He, the designer, and Mr. Fang Bian, the company owner, are the best competition I ever heard to the best dynamic headphones. The HE-6s are characterized by exceptional resolution, without losing flesh, saturation. The HE-500 and the HE-6 sound in an incredibly energetic way and show the events very close to us. They cannot spread the sound images as wide as the HD-800, but show them deeper THERE…
As usually, the choice depends on personal preferences, but in this case mostly on the amplifier partnering the headphones. The HiFiMAN, especially the HE-6, require a strong, probably solid state unit. Should it be a tube amp, it needs to be really strong and preferably with low output impedance. For the photos I used one of the three beautiful stands I own (red, white and black), Klutz Design CanCan.