Home Closed Back Headphone Reviews The Sonic Riddle: Unveiling the HIFIMAN x Dekoni Cobalt’s Auditory Enigma

The Sonic Riddle: Unveiling the HIFIMAN x Dekoni Cobalt’s Auditory Enigma

by Stuart Charles Black
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Big thank you to John Creigan for reaching out and offering to send the Cobalt over in exchange for an honest review!

Greetings mate and Welcome aboard!

Stuart Charles here, HomeStudioBasics.com helping YOU make sound decisions, so…

Let’s dive into a pretty interesting headphone: a collaboration between HIFIMAN and Dekoni; dubbed the “Cobalt.”

Oh gosh, we’re already off to a terrifying start.

Cobalt is also the name of another product from AudioQuest that I absolutely despise, but we won’t venture down that rabbit hole today.

In this review, we’ll run down the Headphone Cobalt version thingie-ma-bob and find out if it’s worth a purchase – discussing its build, sound, amplification requirements, and select comparisons to other headphones I have here at the pad.

We’ll also cover balanced impressions out of a few DACS and see what all the hubbub is about.

By the end, you’ll know if it’s worth the money, and if it isn’t, I’ll steer you in the direction of something that is.



Let’s dive in.

Dekoni x HIFIMAN Cobalt

Price: Check Amazon!

In The Box

HIFIMAN X Dekoni Cobalt Review

Empty Nuka Cola Bottle Not Included.

HIFIMAN x Dekoni Cobalt

3.5mm Cable

1x Velour Ear Pads

1x Fenestrated Sheepskin Pads


The Dekoni x HIFIMAN Cobalt boasts a nano carbon-coated transducer, strategically adjusting the diaphragm’s weight for a nuanced frequency response.

It comes with pre-installed Dekoni Cobalt ear pads featuring high-density, heat-activated memory foam covered in quality fenestrated sheepskin. Also included in the box are velour pads for your swapping pleasure.

Just don’t double dip.

For modders, easy access via jewelers-sized Philips head screws and a quick-clip ear pad system allows effortless swapping to different Dekoni Audio ear pads.

The headphone features common 3.5mm female terminations for straightforward cable removal and replacement.


Donning a featherweight profile, the closed-back Cobalt is incredibly nimble and feels perfect for on-the-go listening sessions due to its agility and compactness.

It is a tad bulky, but the cable is short and I’d feel perfectly fine carrying this around with me. Because it’s closed back, you won’t have to worry about sound leak and potentially disturbing others.

The design is similar to HIFIMAN’s 400se, DEVA, and Edition XS, with its DUMMY THICC adjustment blocks, headband, etc.

HIFIMAN X Dekoni Cobalt Review

This update was first seen in 2020 and works well, opting for a streamlined, utilitarian design with fewer moving parts and a more simplistic appearance.

While very light, the Cobalt doesn’t feel cheap. The adjustments are solid, fairly easy to move, and while the cups don’t fully rotate in any direction, they do move a little – up and down and side to side to get a good fit on your noggin.

Both cups utilize 3.5mm female jacks and can be easily swapped out with any cables of your choosing. More on that later.


There’s no doubt Dekoni and HIFIMAN had comfort in mind when designing such a feathery headphone, and it really pays dividends here.

Clamping force is just right, the headband has an ample amount of padding and also doesn’t dig into the top of your skull (a common thread in HIFIMAN’s updated design), and they don’t move around at all when they’re on your head.

In other words, I can shake my melon rather vigorously and they’ll mostly remain seated in place.

They’re also great for extended listening sessions. Since receiving them, I haven’t had to adjust or take them off for any reason.

Both sets of cups are wide, deep, and do an excellent job of enveloping your ears while keeping them away from the drivers.

This also helps with the sound quality.

Let’s take a listen.


HIFIMAN X Dekoni Cobalt Review


Beginning with the low end, we have a mostly neutral response with just the right amount of impact.

There’s no mid-bass bloat, the sub-frequencies are handled nicely, and to my ears, there isn’t any significant roll-off to speak of.

In other words, this is HIFIMAN bass through and through and something I am most certainly a fan of.

You’ll appreciate the texture and articulation, as bass notes slam with adequate authority while not muddying up the rest of the canvas.

So there’s probably some slight mid-bass emphasis, but nothing overpowering or muddy.

This is especially beneficial with Hip-Hop tracks from artists that tend to mix the bass a bit heavier.

There’s nothing wrong with that as long as it’s done correctly, but you’ll never feel tempted to skip the track due to a bloated mess, as say, you would with something like a Meze 99 Neo.


HIFIMAN X Dekoni Cobalt Review

Here’s where things become problematic, as the mids do suffer from that dip that HIFIMAN is infamous for.

You can clearly hear this in going back and forth with Raekwon’s “Guillotine (Swordz).”

With the K702, his vocals are present and accounted for, cutting through the mix nicely and sounding clear and forward.

With the Cobalt, they’re a bit too recessed for my liking, sounding pushed back and underneath the frequency response.

It’s important to note that the K702 is my benchmark for the ideal diffuse field target, as it’s incredibly neutral while placing some emphasis on a couple of key areas: the presence region and also the highs.

In other words, it’s going to be completely honest with me and let me know how a track sounds.

The problem with the Cobalt is that it doesn’t achieve any of this, and ends up sounding a bit too boxed in and ultimately congested in these all-important areas.


HIFIMAN X Dekoni Cobalt Review

A running theme here is that the K702 sounds perfectly natural and fairly effortless. The Cobalt, by contrast, does not.

I would say that the treble on the Cobalt is peakier and while not overtly sibilant, does present a bit of hiss that you’ll notice in comparison to the tamer 702.

Again, the K702 is almost perfect (in my opinion) with how it portrays the overall frequency response.

There’s sparkle, but it doesn’t sound essy. The Cobalt is not only a bit essy, but it also sounds slightly artificial and thin when going back and forth.

There’s this papery quality about it when listening to a track like Havoc’s “Fallen Soldiers.”

While the K702 sounds full, open, and spacious, the Cobalt seems almost like you’re listening inside a dry-ish box or something.

Yes, it’s closed back, but the Cobalt actually sounds more open than a typical open back, so I thought the comparison was valid.

Regardless of the open/closed debate, the Cobalt is still tuned fairly wonky to my ears.

You may find yourself turning up the volume to compensate for the mid-range dip, and unfortunately, this can be an issue in many of HIFIMAN’s mid-fi offerings.

Resolution & Instrument Separation

HIFIMAN X Dekoni Cobalt Review

I’d say the resolution here is about average, and OK. It’s not going to blow your socks off or anything, but it does the job I guess.

You’re probably not going to feel like sounds are being placed under a microscope, but I suppose that’s fairly typical for a mid-fi offering.

That sort of experience tends to manifest above mid-fi, and at $399, I’d say the resolution is below average for the price you’re paying.

I may be in the minority here (or not) but I found the separation of instruments to be a bright spot in an otherwise fairly dismal headphone.

It almost makes for the Cobalt’s pitfalls and is one of the few reasons it’s at least tolerable to listen to.

No, the overall image isn’t exactly spacious, but the separation between sounds is.

This makes it sound a bit better than typical closed-back headphones, but my problem with the Cobalt is that it just sounds too compressed, boxy, metallic, and… I don’t even know.

Timbre is also fairly disappointing, as, continuing off of the last point, there’s no sense that the music you’re listening to contains actual instruments with unique tonality and realism.

In other words, the immersion factor is close to zilch and it just sounds like vibrations through a driver. I don’t feel close, connected to, or in tune with the music all that much. 

This goes back to the papery, thin quality of the headphones that I just can’t shake – even after many hours of demoing.


I’d say that generally speaking, these work well with most genres, though you’ll probably end up sticking with Hip-Hop, EDM, Pop, and the like.

They aren’t quite open enough for Jazz or Classical, but the bass is adequate for most mainstream music.


JDS Labs ATOM 2 ReviewFortunately, the Cobalt at 16 Ohm Impedance and 101dB Sensitivity means it’s incredibly efficient and doesn’t resist power much.

I’ve been using it with both the DragonFly Red and Go Link, but I think the DragonFly is overkill for these.

The Go Link ends up being a perfect pairing because it provides more than enough power to drive the headphones. Plus, it’s perfectly peachy with an iPhone.

Please, for the love of God don’t overthink this.

The Cobalt needs hardly any juice to get going. Spend more than around $60 here and you’re burning money in my opinion. 

Velour Padding Impressions

HIFIMAN X Dekoni Cobalt Review

Unfortunately, the Velour pads simply exacerbate the already-existing issues present in the Cobalt.

In other words, the sound is even more veiled, dark, and muddy, which is quite a shame. I love how they feel on my head, but I can’t reconcile these problems.

Balanced impressions

Note: I simply swapped out the GL2000’s balanced 4.4mm cable with the Cobalt.

Not much to discuss here. The sound is the same, but perhaps slightly clearer.

I do think that balanced cables make a difference in sound quality, but if you have poor-sounding headphones, it’s not going to suddenly make them sound good.

Other comparisons


HIFIMAN X Dekoni Cobalt ReviewNo contest. The Cobalt sounds like you’re listening to an AM radio by contrast. It’s just nasally and weird. Yes, the 400se is a planar magnetic and superior to a dynamic, but the comparison is still fairly jarring.

On MF DOOM’s “BALLSKIN,” his vocals sound overly raspy, gruff, and lack the smoothness inherent in the 400se.

Think of it like crumpled paper, etc. – only, it’s crumpled aluminum foil or something equally as overt and in your face.

The 400se does suffer from a mid-range dip, but it’s gradual and fairly subtle. The Cobalt’s issues are immediately apparent and noticeable.


Perhaps this is a bit obvious, but the Cobalt sounds rather essy in comparison to the 600’s treble.

Now, the HD600 has been accused of being veiled, but again, there’s no contest here. The HD600 wins by a landslide in terms of overall sound quality.

In fact, the Cobalt’s issues are even more pronounced in an HD600 comparison than they are in swapping back and forth between a 400se and Cobalt.

HIFIMAN X Dekoni Cobalt Review

The HD600, despite all the hate it’s gotten in recent years, is an almost perfectly tuned headphone. It makes the Cobalt sound like something you’d find in your local drugstore.

The same raspiness, boxiness, and general lack of coherence is there but it’s magnified 5 fold now.

It kind of sounds like they were going for that ultra-clarity, but it ends up just faltering quite considerably when compared with studio staples like the venerable HD600.

Final Verdict

HIFIMAN X Dekoni Cobalt Review

Stay away from things named Cobalt, apparently. xD

While there are certainly some good qualities about these headphones (mostly build and comfort), ultimately I think they fall well short of the target sound-wise – diffuse field or otherwise – especially when considering the price tag of around $400. Yikes.

To me, these are, in general, $150 headphones as there’s nothing about them that outperforms say, an M50x, DT990, etc. at those similar price points.

In fact, in my mind, those 2 headphones are better.

And, when you can get a 400se for around $109 (Subject to Change), there’s no way I’d ever fork over the money for this collaboration – even at $150.

I’m in no way trying to dump on Dekoni here, but their pads are overpriced and have been for a few years now.

I’ve talked ad nauseam on this blog about the fact that HIFIMAN, for whatever reason, refuses to manufacture well-built pads for their headphones. It’s mind-numbing.

And now it looks like they’re just doubling down on their stubbornness by collaborating with the company that actually designs them correctly. Absurd.

This was an issue in basically every headphone since the original 400i, and though Dekoni does it right, there’s no reason why someone should have to pay upwards of $70+ for HIFIMAN’s negligence.

That’s highway robbery. Just sell your headphones with pads that don’t fall apart. It’s that simple.

HIFIMAN HE400se Review

So, what should you go with?

I’m not a huge fan of closed headphones anymore, so I’d either get a DT990, K702, or 400se. All 3 of those are a much better value than the Cobalt at its current inflated price point.

Heck, you may as well just splurge on an Edition XS or Ananda at their reduced prices (Subject to change) if you want a real taste of Hi-Fi.

Both represent proper tuning, superior resolution, and realistic timbre, and, when comparing those prices to the price of a Cobalt, it’s frankly laughable that these are $400. 

So, get an Edition XS or Ananda for cheaper/the same price as the Cobalt and fist pump at check out.

And I’m out.

Well, that’s about it for today my friend! I hope you’ve enjoyed this HIFIMAN x Dekoni Cobalt Review and came away with some valuable insight.

Questions? Comments? Requests? Did I miss the mark on something? Please let me know down below or Contact me!!

If you love what I do here and want to support the blog and channel in a more personal way, check me out on Patreon and discover all the value I have to offer you.

Which headphones from my recommendations are you most likely to go with? I would love to hear from you. Until next time…

All the best and God bless,





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