Drop + Dan Clark Audio Aeon Open X Headphone Review

Aeon X Open: High-End Headphones From Drop and Dan Clark Audio
Drop is no stranger to the headphone world, and if you’re even remotely interested in HiFi audio, the chances are good you’ve already heard of them. They’ve made their name among audiophiles on their excellent collaborations with the likes of Sennheiser (HD6XX), Beyerdynamic (DT 177X GO), AKG (K7XX), and many more.
Their model is a good one: find a beloved headphone, partner with the manufacturer to create a new version based on fan feedback, then sell it for less than the original. There’s little not to love with an approach like that, and that’s exactly with the headphone we’re looking at today, the Drop + Dan Clark Audio Aeon Open X.
Originally retailing as the Aeon Flow Open in 2018 for $799, this collaboration offers improved sound, comfort, and customization, on top of Dan’s custom V-Planar drivers, for only $499. It’s a massive discount, but still a premium. Is the Drop + Dan Clark Audio Aeon Open X the upgrade you need to take your desktop audio setup to the next level?
Product Specifications
- Manufacturer: Drop + Dan Clark Audio
- Design: Open-back headphones
- Series: Aeon, Individually serialized
- Drivers: V-Planar planar magnetic, matched +/- 1.5 dB 30 Hz–5 kHz
- Efficiency: 94dB/mW
- Impedance: 13 ohms
- Headband material: NiTinol memory metal
- Ear cup material: Plastic frame, genuine carbon fiber inserts
- Earpad material: Japanese protein leather (removable)
- Input connector: Hirose 4-pin
- Cable: DUMMER 4-pin (3.5 mm) to ¼ in (6.35 mm) , 6’5″ (2 m) long
- Weight (without cable): 11.5 oz (326 g)
- Made in San Diego, CA
Pricing
$499 (Drop.com Store)
Manufacturer Description
An Introduction
Before we get into the headphones themselves, a little about their creator, Dan Clark. Dan has been a guru in the audio world for more than 20 years. He got his start working in high-end audio stores befores developing loudspeakers for major brands like Platinum Audio. When headphones began to rise in popularity he shifted focus. Within the audiophile community he gained acclaim as a modder and an authoritative voice on audio forums. You can still find him on speaking up in forums today, but in the beginning, his early pursuits earned him more than respect: they funded the development of his own drivers.
Since those early years, Dan and his team have developed multiple headphones, each earning high marks among fans and critics alike. It’s easy to see why. The headphones they’ve released are, in a word, artisanal. It doesn’t take more than a quick glance at the company’s catalog to see that these aren’t your average headphones, mass-produced and rounded-off to land at your local Best Buy. They’re unique, hand-made in California even now, and focus on sound and comfort above all else. DCA doesn’t get into the “spec war” like so many other manufacturers with long-winded specification sheets. These are headphones made to be experienced.
The Drop + Dan Clark Audio Aeon X Headphones
One of the ways the Drop (formerly Massdrop) kept prices low was to offer simple packaging. That’s gone out the window with this release. The Aeon Flow Open X comes in a nice hardback box. The art is simple and unassuming, but I found it to be tasteful and in keeping with the overall “vibe” these headphones exude.
Inside, you’ll find a hardback case emblazoned with the MrSpeakers moniker. This is clearly an older case since the MrSpeakers brand is no more, but, hey, if it keeps cost down, that’s no big deal in my book.It lends some credence to fans who have shared that the Open Xs may have began their life as stock from the original run, however.
Opening the case reveals the headphones in all their “thicc” glory (thanks for planting that in my mind, XFX). The upper compartment holds a bag of goodies that includes Dan Clark’s DUMMER cable ($99 on its own), a 3.5mm to 1/4-inch adapter, a set of three tuning filters to swap into each ear cup and customize the sound, and a welcome letter that gives some advice on achieving the best listening experience and burn-in.
Yes, burn-in. It’s a contentious topic in the audio world and not one everyone agrees even does anything. Here, however, we have Dan Clark himself advocating for 100-200 hours of listening to help the unique V-Planar drives reach a “steady-state.” Given the innovative creased design of these planar magnetics (creating the “V” in “V-Planar”)), it makes some sense that they would need time to loosen and settle in. Also, when the designer himself is saying “hey, these need this,” I’m inclined to believe him. More on that later.
The headphones themselves are absolutely gorgeous. They feature an ear-shaped design with a gorgeous midnight blue shell that’s speckled with subtle metallic flake like stardust. But then, maybe I have space on the mind because the outer grill reminds me of nothing more than a spaceship with its hexagon pattern. They are so unique and just look darned cool. The man who brought us the spider headphones brings us the spaceship. Who would have thought?
The pads have been upgraded from the original to the same set on the Aeon Flow 2 ($899). They’re lush one-inch thick and trimmed in Japanese protein leather. The front half of the inner rim has been fenestrated, which Drop says minimizes sound reflections back into the ear to create a wider soundstage. Without being able to try the original set or swap out with another pair, I can’t say whether this is a noticeable improvement, but I am a fan of the clarity and imaging of these headphones, so they certainly don’t seem to be hurting anything. I do wish they were removable so the custom pad world could take a crack at these.
The bottom of each earcup features a sizeable jack for the Mini-XLR connectors on the DUMMER cable, each of which supports locks so you won’t unplug them by accident if the cable catches.
Moving up to the top of the headphone, we have the memory-metal headband and adjustable leather strap. The band is reminiscent of the AKG K7XX self-adjusting headband, but there’s no spring adjustment here. The leather strap attaches to each side of the track on a tight slider. My sample was perfectly set right out of the box, but if you do need to adjust it, it’s as simple as sliding it to a comfortable position.
Fit and Comfort
Despite their large size, the Aeon Open X is remarkably light at 326g. I would have expected 600g based on size alone, so picking them up was quite a pleasant surprise. Despite their light weight, they don’t feel remotely cheap. The shells are plastic, but the yokes are a rigid metal and since the headband is made of Nitinol (Nickel and Titanium), you won’t have to worry about much of anything damaging that. Take care of it and this headphone should last a lifetime.
That lightweight design is one of the Aeon Open X’s best characteristics. I was a little worried about the lack of padding on the headband, but these headphones don’t need it. I was able to wear things for 6 hours at a time without any soreness at all, and I tend to experience pain at the top of my head easily. The leather band did a good job of conforming to the contours of my head without adding unnecessary pressure.
The headphones are quite grippy and create a good seal around my ears. The plushness of the ear cushions helps mitigate what might otherwise be too much grip, but since they have so much give, they wind up feeling comfortably snug. The open-back design and fenestration help immensely with heat build-up too. Even in my upstairs office with temperatures in the upper 70s, these never caused my ears to sweat.
The only thing I wish was included here was more articulation in the earcups. The yoke design allows for a good amount of tilt but they don’t rotate to lay flat around your neck. Since they’re so large, they quickly get in the way if you need to turn your head.
It’s also worth noting that these aren’t headphones you can easily wear out of the house. Technically, yes, you can and may even want to since it’s possible to drive them on a smartphone, but if their cost weren’t enough for you to keep them home, their size will likely cement that decision.
Listening Impressions
I’ve spent a good few weeks with the Aeon Open Xs now, and it’s at this point that I can say that Dan Clark’s recommendation on burn-in is absolutely true. The headphones sounded good right out of the box, but over the course of these weeks, the sound has opened up. I have particularly found this to be true with the bass which has become much more full while still remaining impeccably tight.
Looking at the frequency response chart above, we can discern a few generalities about the headphone. Instead of a Harman-like V shape, these cans have close to an m-shaped curve. Until 80Hz, the bass is mostly flat before descending into slightly lower mids, and elevating again in the middle-highs. We then see the treble tempered with a pair of valleys at about 9.5kHz and 16kHz before flattening out again.
Helpfully, Drop has included a comparative response chart that places the original Aeon Opens side-by-side with the Open Xs. The tuning has clearly been modified but the changes are slight. We have a bit more of a mid-bass hump, and slightly elevated middle-highs and highs to add detail and “air” to the sound. This is where fan feedback comes in, refining the Open Xs to something closer to what the community has shared they’re interested in.
These frequency response graphics only go so far. Let’s get into my real, lived experience.
As you might imagine, I spend a lot of time writing and listening to a genre called Chillstep. It’s melodic, atmospheric electronica, and is the perfect genre for pushing the dynamic range of these headphones. The bass response is what I always imagined when people would describe “that planar magnetic bass.” It is big and full and rich in a way I haven’t heard on a headphone before, including other planar magnetics like my Audeze Mobius. These headphones don’t rumble — that’s the flat sub-bass for you — but they have an absolutely filling sound that washes over the soundscape like a wave.
At the same time, they never lack for detail. The song Hope Well by Namaste is filled with layered synths, chimes, bells, snaps, voices, and a multitude of percussion, and every element can be picked out of the mix. My Beyerdynamic DT-990 PROs would often over emphasize these details into sharpness, but here they sparkle instead of pierce. Vocals, and particularly female vocals, seem to sit further back, which makes for easy listening, especially on those that can sometimes sound sharp, like Claudio Sanchez in Coheed and Cambria’s, Mother May I.
You can also customize the sound using the ear filters. Drop and Dan Clark Audio include four filters, increasing in sound damping to cut down on the highs and, by proxy, make the bass sound more present. I found myself leaning on the single-notch white filters (the least damping) in the beginning and eventually settling on the stiff felt filters (second highest) as the drivers burned in.
The dynamic range on these headphones is also outstanding — but, to make the most of them, you’re going to need a moderately powerful source. At an impedance of only 13 ohms, you can drive them from your PC, smartphone, or even a game controller, and they’ll sound fine. With a proper source, the dynamic range expands and the bass tightens up substantially. I started by driving them with a Schiit Audio Asgard 3, but spent most of my time with them plugged into my GoXLR Mini without any noticeable difference. If your motherboard supports high gain output, like the ASUS Maximus line, you could conceivably get fantastic results without any intermediary in the chain. I’ll say it again, though: even running on my Note 9, they still sounded very good and could even get quite loud.
The soundstage on these headphones is a bit smaller than I expected. If the Sennheiser HD6XXs image like an open space, these are tantamount to sitting between two speakers on opposite walls of a room. For music, this is still very good and allows you to hear the relative position of the different instruments, and is also great for gaming.
It may seem a bit silly to look at a $500 audiophile headphone for gaming, but as a PC gamer, I need my kit to deliver for more than just music. The sense of depth in a gaming soundscape is wide enough that it’s as if you have your own little glass room within the game world. The positionality is also top-notch, so being able to pick out the direction of footsteps and gunshots is easy, and you don’t have to worry about the reverb-soak that often happens with virtual surround sound — and that’s really the metric right there. I would take these over a normal gaming headset any day of the week. In times when I need surround sound, Windows Sonic is more than adequate.
Conclusion
Put simply, these headphones are fantastic. I could nitpick about the lack of rotation on the earcups, that the low impedance can be slightly misleading, or that you can’t remove the pads, but at the end of the day the impression I’m left with is just how fun these are. They have a unique, enveloping sound with lots of bass and an impressive amount of detail. Whether I’m zoning out to music, playing games, or catching up on Netflix, these are the cans I’m reaching for.
At $499, they’re expensive and clearly won’t be for everybody, but if you’re looking to take your audio setup to the next level, the Drop + Dan Clark Audio Aeon Open X are an outstanding way to do that.

Review Disclosures
This disclosure statement covers the way the product being reviewed was obtained and the relationship between the product's manufacturer and PC Perspective.
How Product Was Obtained
The headphones are on loan from Drop for the purpose of this review.
What Happens To Product After Review
The headphones remain the property of Drop but will be on extended loan to PC Perspective for the purpose of future testing and product comparisons.
Company Involvement
Drop provided the product sample and technical brief to PC Perspective but had no control over the content of the review and was not consulted prior to publication.
PC Perspective Compensation
Neither PC Perspective nor any of its staff were paid or compensated in any way by Drop for this review.
Advertising Disclosure
Drop has not purchased advertising at PC Perspective during the past twelve months.
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Would you be able to write a comparison of this against hd6xx, give latter is like a reference set from drop?