Dark or Light

HarmonicDyne PD1 Review

HarmonicDyne's First IEM is a Unique One

Christopher Coke Posted:
Hardware Reviews 0

HarmonicDyne has developed an excellent reputation for its over-ear, open-back headphones. We last visited the brand with the HarmonicDyne Zeus, an outstanding headphone for audiophiles and gamers alike. Today, we’re looking at the company’s first in-ear monitor, the PD1. It’s an interesting beast, combining a 10mm planar magnetic and 10mm dynamic driver to deliver natural sound full of “sparkle and energy.” Coming in at $379, that combination of drivers doesn’t come cheap but has the potential to deliver an outstanding listening experience. 

Is HarmonicDyne’s first time the charm with the PD1? Let’s dig in and find out!


  • Current Price: $379 (Linsoul
  • Dual Drivers: 10mm planar magnetic, 10mm dynamic driver
  • Materials: CNC Aviation Aluminum Shells
  • Impedance: 16 ohms
  • Frequency response: 10 Hz – 40 kHz
  • THD + N: 0.2%
  • Sensitivity: 110 dB
  • Housing material: Aviation-grade 7075 aluminum alloy
  • Cable: 4.4 mm copper-silver balanced cable, 3.5 mm OFC silver-plated unbalanced cable 
  • Connector: MMCX
  • Length: 1.4m
  • Weight: 6.5g each

HarmonicDyne PD1 - Overview and Unboxing

The HarmonicDyne PD1 is out to make an impression. That begins right from the unboxing experience with one of the most unique boxes I’ve seen for an audio product. The box is textured in a paper-like manner and a small decorative sleeve must be removed to access the larger box. High marks for outward presentation.

Once the box is opened, you’re presented with the IEMs and a travel case displayed on the left and a selection of silicone ear tips and metal ownership card on the right. (As an aside, don’t mind the one black tip. That’s a stand-in as the other is in-use). Mine unit was serialized No. 134, so I’m testing a unit early in the production run. We’ll dig more deeply into these accessories shortly.

Underneath the ear tips are two boxes that each house a separate cable for these IEMs. That’s right, while it’s common for IEMs to include detachable cables, the PD1s include both a balanced and single-ended cable to make sure it can connect to your gear and really be pushed to their limit. These cables are an absolute high point to the package, each thick and rope-like with tightly-woven braids. Despite their girth, they don’t kink or coil easily, which makes them easy to wear and manage. Both also avoid microphonics - the noise that transfers up the cable when coming in contact with your shirt or jacket. There’s also a ¼-inch adapter for the single-ended cable. 

Taken as a whole package, it’s a generous package. The cables alone could easily run upwards of $75 purchased outside of this bundle. The other items are only so-so. The case looks nice but feels pretty thin. The ear tips were also problematic, the black tips too loose to fit securely in both ears and the red tips too firm/too large to wear without completely sealing my left ear canal without leaving my jaw slightly slack. Everyone’s anatomy is different, so your mileage may vary, but I’ve never been able to not find a fit before.

Moving to the IEMs themselves, we have aluminum shells with a beautifully reflective finish. The faceplates protrude a touch, causing reflections to scatter in an appealing way. The overall design follows traditional Universal IEM shaping with contours allowing the PD1s to nestle into the natural folds of the ear without sticking out too much. There’s a triple-point vent on the back rear of each to relieve pressure and enhance their comfort. The nozzles are also long enough to fit securely in your ear canal — assuming you don’t have the same issue I did with the stock tips. 

Inside those shells, the PD1s feature a hybrid driver array. Each shell includes a 10mm planar dynamic driver for the mids and highs. Bass duties are covered by a 10mm dynamic driver. Planar-driven IEMs are still somewhat uncommon in the IEM world but are no longer unheard of. The idea is an appealing one: all of the detail and clarity of a planar without the bulky over-ear package you would typically be forced to. The dynamic driver has also been enhanced with a diamond-like carbon dome and carbon nano-tube edges. 

The downside to including planars in an IEM is that they are notoriously power hungry. With an impedance of 16 ohms, you might think that PD1s are easy to drive but don’t be hasty. These IEMs will run and sound decent with a $20 dongle DAC, but depending on what you’re driving them from they just won’t sound their best and may experience rare audio artifacts (like distortion around the fringes of certain vocals). You have to give them more power. I recommend picking up an affordable portable amp like the Fiio A1 or Topping NX1 for use on the go. At home, I ran them from my XDUUO XD-05 Plus but was able to push them just fine with both my Presonus audio interface and GoXLR, so don’t break the bank on amplification. Still, amp these earphones.

HarmonicDyne PD1 - Fit and Comfort 

Never before have I felt so much like the Princess and the Pea. Using the included tips, I wasn’t able to find a reliable fit no matter which combination I tried of each color. The black tips are softer and worked better for my left ear, but were too small for my right. The red tips are firmer and worked great for my right ear, but even using the smallest size, were too large for my left. Inserting it enough to feel secure and deliver the proper amount of bass, closing my jaw sealed off my ear canal enough to completely kill the sound. Given that ear tips can impact sound, mixing and matching wasn’t a good option either. Very, very weird and a first for me across dozens of IEM reviews.

Thankfully, I was able to pull another pair from a set of Fiio headphones I had nearby and solve the problem. The ironic thing is that this problem could have been avoided entirely if HarmonicDyne had included a set of foam ear tips, but despite the high price, it was silicone only.

With the ear tip issue sorted, comfort is actually quite good. Full-aluminum IEMs can be heavy and slip out over time, but that wasn’t the case with these. The buds are medium-sized and were able to be supported easily by my outer ear and stayed in place well. Even after several hours, I didn’t experience any soreness or irritation. 

HarmonicDyne PD1 - Listening Impressions

HarmonicDyne has an interesting description for these headphones. They emphasize the “natural” and “soothing” sound signature with “good sparkle and energy.” Those two descriptions almost seem at odds, but after spending a couple weeks with these headphones, there really is a dynamic quality to these earphones that allows them to work for relaxed, acoustic music all the way to crashing heavy metal with a pleasing overall sound.

So let’s break that down. These headphones have a U-shaped sound signature. The bass is deep and rich, so when kick drums and low bass lines kick in, you can really feel their impact and presence. The planar driver does a good job of pulling out mid- and high-frequency detail, which is where the sparkle comes in. Listening to acoustic or atmospheric jazz, like Arve Henriksen’s Saraswati, I was repeatedly surprised by how well articulated tiny details in the mix were. Chimes, quiet cymbals or high hats, didn’t break up prematurely. In the mids, vocals are indeed intimate and natural sounding. Instruments in this range, like trumpets, impressed me with how detailed they were. Clearly, the tuning and driver combination are well done and finely tuned.

Another thing worth mentioning is that the PD1s have one of the bigger soundstages I’ve heard from a closed-back IEM. I’m not sure how they do it, but I found myself double-checking my phone to make sure Dolby Atmos wasn’t enabled throughout the review process. These IEMs won’t replace a good set of open-back cans, but the sense of space and air they deliver is impressive.

But with that, we have to return to power. Despite their 16 ohm impedance, these earphones just don’t compete without enough juice behind them. Much like the Tin HiFi P1s, I suspect we’ll see opinion split on these headphones among people who are driving them with some kind of amp and those plugging straight into a phone or headphone jack dongle. Likewise, they just need volume.

Before writing this review, I went back and forth between a basic dongle DAC and my desktop amp listening to Spotify on its highest quality setting. There is an immediate and noticeable bump in detail and space moving from a low-powered dongle to a proper amplifier. Worse, listening through that dongle DAC sometimes resulted in audible distortion at the fringes of male vocals. This did not occur on the exact same tracks with a proper amp. Give. Them. Power.

Final Thoughts

The HarmonicDyne PD1s are an interesting earphone. Not only are they a departure from what the brand has done before, but the blend of planar and dynamic drivers isn’t exactly common in the earphone space. I really enjoyed their sound signature and the added crispness the planar delivers in the mids and highs. The bass is also darned good and really fills out the music with real weight.

The sticking point here is price. At $379, they’re an expensive headphone that essentially demands outside gear, be that ear tips or an amplifier. I really enjoy these earphones, but at the current pricing, they have steep competition that also delivers outstanding sound quality without the need for an amplifier to really sound their best. The PD1s are doing something unique, however. The planar dynamic blend works well and, frankly, has a higher cost to implement. The two inclusion of not one but two excellent cables helps mitigate the high price, too. 

The point here is that this is a reserved recommendation. These earphones have a lot going for them, but they’re worth really considering before pulling the trigger at this price.

The product described in this article was provided by the manufacturer for evaluation purposes.
  • Excellent bass response
  • Great detail retention in the mids and highs
  • Two high-quality cables included
  • Excellent build quality
  • Comfortable long-term fit with proper tips
  • Quite expensive
  • Problematic fit with included tips
  • Requires ample power to sound their best


Christopher Coke

Chris cut his teeth on MMOs in the late 90s with text-based MUDs. He’s written about video games for many different sites but has made MMORPG his home since 2013. Today, he acts as Hardware and Technology Editor, lead tech reviewer, and continues to love and write about games every chance he gets. Follow him on Twitter: @GameByNight