Closer Examination

The cables that come with the HarmonicDyne P.D.1 are likely the best of any IEMs I have tested to date. Take the more "basic" 3.5 mm cable for instance, which has a gold-plated TRS plug in a substantial 45° angled housing. This leads to a braided 8-strand cable with silver-colored PU insulation over silver-plated oxygen-free copper conductor cores, which results in a thick, durable cable that oozes quality as it leads to the Y-splitter with the HarmonicDyne logo on it. Four strand of cable then go to each channel, and these have a transparent sheath over them towards the other end to help with the memory wire design. The cables terminate in a similarly colored and designed housing for each channel, which also have L/R markings with MMCX connectors as seen above.


If this was not enough, we get a whole second cable to address balanced needs. This one has a 4.4 mm Pentaconn (TRRRS) plug, which I am quite glad to see since it is clear now that the 4.4 mm connector has overtaken the 2.5 mm TRRS connector for balanced connector needs on portable audio systems. This cable is even better built given balanced outputs can supply more power. We again get eight strands, but it is now a hybrid copper/silver cable that looks the part and acts like it despite the weave by default being looser than on the other cable. Both cables came with a measured resistance of under 1 Ω from end to end, which is even more amazing considering the two cables are also longer than average at 1.4 m. These also exhibit no microphonics in use, at least when used with the P.D.1 without much rustling or movement. They can be a touch stiff, but did not pose any issues when used normally with the cable either behind or dangling in front.


The two earbuds of the HarmonicDyne P.D.1 come separately packed without the cable installed—perfect for me to examine them more closely. The company claims to use "aviation grade aluminium alloy," which is no different from the aircraft-grade aluminium alloy keyboard manufacturers love to flaunt and really doesn't mean too much for consumers. The build quality is good, and the ear buds look quite nice. This is really all that matters, and the use of CNC machining to get the various angles on the face plate results in facets that reflect light differently depending on how you hold them to the light. It also means that the ear buds can be supported at different angles on the face plate, which helps with different photography angles from the norm.


A trim surrounds the face plate, but everything is otherwise left in the native aluminium color you are thinking of. There is also no branding at all, which is unheard of for IEMs these days. This is a three-piece construction including the trim ring, and around the middle are some signs of excess glue up close. It isn't noticeable normally, and certainly can't be felt, either. Three vents have been put on the side towards the top, with a mesh filter underneath, and a fourth vent on the inner surface makes contact with the ear itself. This should allow for good airflow through your ears and out, but we will see how it affects seal on the next page. There is also an L/R mark if you were not sure, but the IEMs maintain an ergonomic design that should help better fit them in your ears. As expected given the cables from before, we see the use of MMCX connectors here, and the angled nozzle is meant to be directed into your ear canal better than just a perpendicular nozzle relative to the shell. The bore is on the larger side at ~5.1 mm, and a lip helps retain the ear tips. We also see a mesh filter at the end to prevent contaminants from entering the acoustic chamber.


The ear buds came with a second set of Type B size M ear tips pre-installed, and replacing them is trivial since the nozzle is pretty cylindrical at the contact point; simply push in the bore of the ear tip you want to use until it catches in place, and make sure it is in fully all around. Seen above are the Type A and Type B silicone tips on the ear buds, both in size M. The silicone is a safe bet for those who don't like the squishier feeling of foam, which can be more isolating and allows for a more secure fit, but may cause some skin allergies to flare up. I found myself preferring the Type B tips over the Type A ones, with the former also reminding me of the SpinFit tips I quite like. You can also see how the Type A tips are lower in profile, meaning the mesh and acoustic chamber is closer to the end of the flange than on the Type B tips. It can affect the sound signature slightly, with Type A tips more balanced by design, but it all really comes down to the seal they provide.


Attaching the cable is trivial since there is no wrong orientation with MMCX connectors. My main issue with MMCX is the fragility of the connectors, so much so that there is a sliding scale of quality with some clearly better than others and a few that may well fail over a short period of time. These seem fine, but I can't test for longevity, of course. Attaching and detaching MMCX connectors can be a pain at times, and manufacturers often include some sort of tool to help with the detachment in particular. The thicker, more solid-feeling housing on the connectors helps provide enough grip to easily detach the cable from the ear buds, but be sure you have the connection points in line with each other when doing so. The 45° angled adapter on the other end also comes in handy for cable management, but it's still a weird in between where I would have rather seen a straight low-profile adapter or 90° angled adapter instead. I know there are many who prefer to use IEMs throughout, but I like to use over-ear headphones when sitting down and IEMs/TWS earbuds on the go. I hence chose to use them primarily with the Qudelix 5K, which has become my new favorite portable DAC/amp and will get its own review soon.