I've owned a pair of these headphones for just under a year now, and my love for them has only grown stronger. I feel like I've spent enough time with them to be able to write an in-depth review, and feel compelled to explain a few things that some reviews miss, which may be helpful to prospective buyers. I've broken down my review into sub-sections for clarity.
SOUND QUALITY & EXPERIENCE WITH DIFFERENT DEVICES:
Apart from a requirement that a headphone be durable enough to not disintegrate in the hand, the sound quality it provides is surely the second-most important aspect, especially for one of a higher-than-average price. We can tick the preliminary box. Now, the sound quality of these can be summed up as airy, light, and silky smooth in the upper-mids and lower treble. Bass is controlled, precise, and extends well into lower ranges - but it's not boomy. It's not exaggerated. It's present, but it doesn't kick. Listen for it, and it's all there.
Bass is something of a tricky issue with headphones, because people's past experiences and expectations define what they think is 'good sound'. I don't blame anyone for wanting some 'thump' to their bass; it's often a pleasant experience. However, in this case, the H6 was designed to reproduce sound faithfully, and a faithful reproduction is not one that swamps most of the sonic palette with immense bass boom. The only problem with the neutral bass characteristic of these is that, when wearing them outdoors, and when any kind of ambient noise is occurring, which of course it usually is, your perception of the bass may be slightly dulled. As such, if you're out in a busy place listening with these whilst walking, you might on some occasions find the bass to be a tad 'anaemic'. However, I've been walking almost daily with these for almost a year, and the sound has pleased me around 95% of the time.
Nothing in the audible sonic spectrum is recessed or greatly exaggerated, except for a slight mid-peak at around 1-2kHz that the reviewer Dalethorn has pointed out already. This usually has the effect of bringing forward higher-pitched, smoother-timbre vocals, which to my ears has only ever been pleasant, but which could possibly be less tasteful in some rare applications for some ears.
As for the experience with different devices, they sound great plugged straight into an iPod classic - and thus most likely all other kinds of iDevice; they were built with portability in mind, and definitely don't need an amp to shine sufficiently. However, if you plug them into an extra amp, be it a portable headphone amp or a desktop amp or speaker amp, they will sound slightly 'fuller', perhaps 'weightier' and the soundstage may be improved variably. I'm no electronics expert, but I would hazard that this has less to do with the amount of power supplied, since these are relatively low-impedance headphones anyway, and more to do with the intrinsic quality differences between low-cost dac/amps in iPods, and higher-cost dedicated dac/amps. The bottom line is that plugged straight into a portable player, these things sing very sweetly indeed.
On a more subjective note, I'd like to add that the 'silky smooth' texture I mentioned earlier is actually one of my favourite qualities of these headphones; I own the AKG K550 and the legendary Sennheiser HD 600, and though the AKG has a great soundstage and imaging, and though the HD 600 has an overall more refined sound, the H6 is the only headphone out of these three to give me an extra, subjective pleasant 'feeling' in my head; there's something I find so 'sweet' about the presentation of the mids and treble, and it strikes me every time. I'm interested to know if anyone else who owns these has the same experience.
BUILD QUALITY & THE PHYSICAL PRESENTATION:
In terms of build quality, the H6 is quite superb in most ways. These are light, yet solid-feeling. The hinges that allow the earcups to rotate are smooth and assured, the extending arms are solid and well-designed; easy to adjust. The leather on the headband is tough, yet smooth-feeling to the touch. It has a nice thickness, and looks great stitched onto the aluminium-reinforced, polycarbonate, fabric mesh-covered headband frame. Some have concerns over the unfinished-looking sides of this piece of leather, but I can assure you that this leather has been treated by B&O so well, it makes for no detriment at all.
The leather on the earcups is sheepskin, as opposed to the calfskin of the headband, so it's exceptionally soft, and feels rather like one's own skin behind the ear and around the top of the neck. Chamfered aluminium plates encapsulate the 40mm headphone drivers, and a fine-grained concentric etching produces a very eye-pleasing radial sun-burst effect against the light. The plastic this plate sits on does not feel low-quality to me; indeed, plastic does not have to mean 'cheap and nasty'; this stuff seems scratch-resistant, solid, and a good choice to reduce the weight of the headphones.
The only thing that alarms me about the earcups are the sharp-edged plastic rings around which the earpad leather is stitched to retain it. The edges of the plastic plates in the earpads themselves can be felt through the thin leather of the earpads, and produce a circular relief on the leather they meet from within. I worried about the potential for tearing here for some time, and in one unfortunate drop I experienced recently, as the headphones caught against my bedside table after slipping off it, the leather of the right earpad did indeed tear a 3 mm section against its inner retainer ring. The earpads can be removed with a firm anti-clockwise rotation about the earcups, and replaced. As a temporary fix, I used some Bostik leather adhesive to fix the leather back together.
Another potential problem with build quality can be found in the cable that comes supplied. While the cable is quite thick, and feels strong, there is some concern over quality control over the plug terminations; the termination on mine at the end furthest away from the iDevice remote has a slightly crooked plug. I should emphasise that this does not seem to be the case for most people's units, and the cable is removable and replaceable! The crooked plug my cable has does not affect sound quality, but does look annoying when sitting perpendicular from a device, against which a slightly crooked angle is visible. I have read a few other reviews mentioning the same problem. Further, I don't like the rubbery texture of the cable flex, which is very clingy, and tends to pull on clothes, potentially straining connections. The cable is also quite microphonic against clothing. This may bother me more than others, though.
Despite a couple of issues, the headphone itself is remarkably well-built, and together with the sound quality for the price for which these are available, I am very pleased overall.
As a piece of design to enjoy off-the-head, they're exquisite, as can be sampled from photos, and I challenge anyone to think differently. Jakob Wagner has excelled himself with his design.
Thanks to their lightness, the H6 is very comfortable on the head, with the memory foam earpads resting well against the ears, especially after warming up a little. Despite being closed-back headphones, the leather on these earpads breathes very well; I tend to sweat while wearing my AKG K550s, their protein leather perhaps not being so breathable. Clamping force is not too tight. I dare say the earcup openings are not quite big enough to avoid touching the entirety of the ear, but the pads and leather surrounding them are so soft, after a bit of wiggling around, you tend to ignore their presence.
Off the ear, don't worry about the lack of a hard carrying-case - extend the arms fully and hang them around your neck, cups faced against your chest, and you have a comfortable, non-intrusive style-statement (not fashion) and temporary storage solution.
I have thoroughly enjoyed my time with the Beoplay H6, and plan to continue enjoying them for a long time. If you're not a bass-head, and you've been thinking about a conveniently-sized, over-ear, closed-back headphone in this price range that works great for portable use and looks beautiful, then don't hesitate. As of January 2015, some of the World Cup special edition Pepsi-collaborative H6s in blue leather are still available on Amazon, so if you want to save some more money, you might consider those instead of the standard Black or Tan versions. For around £179, those are an absolute steal - and for the higher prices, well, I think they're well worth it.
Thanks for reading; now get listening!