Closer Examination

The reason we were provided a 4.4 mm to 3.5 mm adapter with the HarmonicDyne Zeus is now obvious—the stock cable is terminated in a 4.4 mm TRRS balanced connector for the source. This is a bold move since next to no desktop sources cater to this connector, and even portable sources have only recently started using it owing to the cost of the connector. It has a plastic cover on it for protection, and the metal housing matches the design language of the adapters with a knurled finish towards the bottom where the cable wire enters the picture. This is a substantial cable too, using thick paracord that is braided very well. It's still denser and stiffer than I would like my headphone cables to be, and kept the folds it shipped in even when stretched out. It took over 5 hours of re-shaping before the cable cooperated, though it remained in position to where this is similar to memory wiring in IEM cables, I suppose. The splitter is of a similar design as the other metal components, but we see the smooth base with the HarmonicDyne logo on it. It is after the split that there are clear signs of the promised OCC (Ohno Continuous Cast) high-purity copper conductor, with two braided strands per channel terminating in two 3.5 mm TRS connectors. These come marked as such, and all the connectors are gold-plated for oxidation resistance. Note how ridiculous it becomes if you need to use a desktop source with a 1/4" (6.35 mm) headphone output though, since you first need to go from 4.4 mm female to 3.5 mm male to convert the stock balanced cable to single-ended, and then from 3.5 mm to 6.35 mm—both adapters are needed, and you end up with an unsightly looking adapter chain. A replacement cable might not be a bad idea thus, and I recommend the Tripowin Granvia in the length, color, and connectors of your choosing.


I had a good idea of what the HarmonicDyne Zeus looks like going into this review, but still had an audible "whoa" moment when I first took these out. Aesthetics are certainly subjective; however, calling these striking would be fair. Front-on, it does not seem all that different, with a headband that has foam padding towards the middle to support the headphones on your head. This is an over-ear set of headphones with large and deep ear pads too—so far so good. It's at any other angle that the Zeus makes its presence felt, which makes the design language HarmonicDyne set across its Helios, Zeus, and Poseidon series of headphones apparent. The steel headband is semi-open on the top with a plastic frame over it for some structural integrity and aesthetics, but we then have genuine walnut wood inlays combined with more of the same on the ear cups, too. The ear cups have a complex geometric pattern that seems right at home inside a kaleidoscope, and it is sharp in more ways than one. The headband with its plastic frame forms a natural segue to the ear cups, and the composite of foam and plastic on a moving part hides the sizing steps if not used. L/R markings also indicate the left and right channels respectively, with the serial number matching the one on the case.


We now get to take a closer look at the walnut wood inlays in the headband, as well as the steel band for sizing, structural integrity, and clamp force. Instead of having discrete steps cut into the steel band on either end, the sizing happens by moving the plastic frame and wood inlays around the steel itself. While technically the same thing, it results in more play between moving parts, which does not feel great in practice. In fact, notice that gap between the wood or plastic and steel that dust would love to get into. This will eventually fail, I just don't know when. HarmonicDyne did mention that this mechanism has been improved in the newer Poseidon, though whether they responded to customer complaints or deemed it an actual issue is unclear. The other issue I have with this sizing mechanism is that anything other than the shortest, fully closed setting results in exposed steel on either side, which changes the aesthetics of these headphones. Sizing options are aplenty, however, so these may be used with heads small and large alike.


Apart from the accessories, aesthetics, and build quality, one thing that you do get with the Zeus compared to the less expensive HIFIMAN HE400se and Sivga Robin is an articulating support system for the ear cups. On the outside is where subtle HarmonicDyne branding has been put, and below it, a tested horizontal swivel-point implementation moves around self-lubricating plastic planes. This has the C-frames, if you will, connect to the ear cups at two points on either side of the cups and then move nearly up to 360° horizontally and just slightly less vertically, as the thickness of the C-frame stops the ear cups from completely rotating as with the HIFIMAN Arya. The HarmonicDyne Zeus is thus extremely customizable when it comes to fitting them to your head and over your ears as best as possible.


Here is a closer look at what is effectively the face plate equivalent for IEMs on the Zeus, which is a machined metal disk that has been cut into this symmetric geometric pattern. Make sure not to move your headphones with your hands on it since the metal is somewhat sharp and quick motions can be jarring. It won't cut your fingers, but sure won't feel nice. Behind this grill is a finer metal mesh; it is so fine that it is primarily about aesthetics, not a wave guide akin to what the likes of Audeze and HIFIMAN have done. As such, this is among the lesser open open-back headphones I have used, so semi-open might be a better description. The other side hosts the ear pads, and HarmonicDyne is using soft suede pads with medium-density foam filling. These are among the most comfortable to wear courtesy them being so thick that your ears are easily put inside them, but suede or velour seals differently and does not sound the same as leather, pleather or hybrids. These will also pick up dust, hair, and ear wax quicker than the others, so have a lint remover on hand. There is no contouring to the ear pads; as seen above, they are quite circular.


The good thing is that these pads are easily replaceable, at least in the sense of HarmonicDyne going the traditional route of having them squeeze into a gap around the ear cups. New pads can be separately purchased for $50 a set, which are described as "nano-velvet cushions with a geometric inner membrane" and still easier to remove than install. This gives us a closer look at the inside and sides of the ear pads, including the inner screen keeping the drivers clean.


At this point, we can also get a closer look at the 50 mm dynamic drivers. These are offset for sound closer into your ear canals, and the baffle is placed accordingly. HarmonicDyne is using marketing to claim these are beryllium drivers, but they are Be-coated at most. The driver assembly is held in place inside the ear cup with four Phillips head screws, two of which are under telltale stickers. Removing these allows a look at the underside, including the thin wires going from the cable connectors to the onboard PCB. At this point, you might as well remove the grilles as I did here.


Doing so reveals an acoustic screen on the outside after all, which is built to capture unwanted resonances that would affect the listening experience. Enterprising readers may find this section relevant, an inspiration to design their own grilles perhaps, which is a disc held in place inside a support frame.


On the bottom of the ear cups, placed closer towards the front, is where we find small cutouts for the cable connectors from before. These have the cable plugs connect easily enough, which naturally directs the cables away from your body and comfortably sets them down at the splitter on your chest, or a desk when sitting down. The HarmonicDyne Zeus has dual 3.5 mm TRS connectors on the ear cups to increase compatibility with aftermarket cables, which is handy if you don't like the stock cable. With the two cables meeting centrally at the splitter and moving to the source, weight balance is still centrally placed as it then heads to the source. The cable is a standard 2 m long before any adapters, making it too long for portable use and only about adequate for a desktop setup.