HiFiMAN DEKONI COBALT HEADPHONES REVIEW

Oscar Stewart takes a listen to the HiFiMAN Dekoni Cobalt headphones costing £499.

The Dekoni Cobalt headphones come nicely packaged and with two sets of interchangeable earpads to tune their sound to your own preference.

Dekoni started out making earpads for headphones, offering a very comprehensive catalogue of different pads for different brands, in various materials. The design and material of an earpad greatly influence the sound of a pair of headphones, and Dekoni was one of the few companies out there offering premium replacement parts.

A few years ago, they teamed up with Fostex for their first headphone release the Dekoni Blue, based on the T50RP but with tweaked baffles, blue cups, and Dekoni Hybrid earpads. Fast forward to 2023 and they have teamed up with Hifiman for their next headphone release. Now, like Fostex, Hifiman are well known for their planar magnetic headphones but the Cobalt uses a dynamic driver in a closed-back design. This driver has a carbon coating and the coating can be applied in specific areas to allow extreme fine-tuning of the sound, and the overall sound in these was tuned by Dekoni’s own engineers.

I know Hifiman can make some excellent headphones, but a closed-back dynamic driver headphone is something a little different for them, so let’s see how they sound.

What’s in the box

BUILD QUALITY AND DRIVEABILITY

The Dekoni Cobalt is built to be lightweight yet durable. The earcups are plastic but don’t feel flimsy, with a 3.5mm socket on the bottom of each for the detachable cable. The cable itself is a standard rubberised copper cable that goes from a single 3.5mm jack to dual 3.5mm jacks at the headphone end. A 3.5mm to 6.3mm jack adapter is included.

Dekoni opted for a heavily padded headband which feels great. The headband yokes are metal and have a certain amount of swivel built in for comfort. Out of the box they have Dekoni Fenestrated sheepskin earpads fitted, as this is the earpad Dekoni chose for their preferred sound tuning. The first 1000 units will also include a pair of Dekoni Elite Velour earpads for additional sound tuning.

Overall, the build quality is good, they don’t feel overly premium or substantial, but the lightweight build does help when it comes to comfort. There is a nice mix of plastic and metal and the headband padding is very good, I can’t find any weak spots and they do feel built to last.

Rated at 16Ohms and 101dB sensitivity these are not the hardest to drive, however, the 45mm drivers do benefit from a little power behind them to keep them controlled. I did find them to sound slightly fuller out of a proper desktop amp (Singxer SA-1), but most DAC/Amp combos and dongles should do them justice (they sound great with the iFi GO Link for example).

COMFORT AND ISOLATION

As mentioned, the Dekoni Cobalt is a lightweight headphone that really does help when it comes to the comfort of a pair of headphones. The Fenestrated Sheepskin earpads are also key to making these an incredibly comfortable headphone for long listening sessions. The holes in the earpads help keep your ears cool, despite the headphones closed-back nature, and the memory foam inside the pads provides excellent cushioning and conformity around your ears. Generous headband padding provides a good distribution of weight on top of your head, preventing hot spots.

The Dekoni Cobalt are a closed back headphone that offer a reasonable anount of isolation and protection from sound leaking

I found the Dekoni Cobalt to be extremely easy to wear, and listen to, for hours on end – perfect for those who need some kind of isolation for all-day listening sessions.

In terms of isolation, they are not like a studio headphone that blocks out a sizeable chunk of outside noise, instead, they dull keystrokes slightly from keyboards and you can still vaguely make out voices with music playing at a normal listening level. To be honest, for what these are designed for, this makes sense as you’ll likely still be able to hear someone trying to get your attention or ringing your doorbell. They still offer up an ok level of noise reduction to reduce distractions from outside noise. So no, they’re not a heavily isolating closed-back headphone, however for office work and working from home they do a good job. They do leak a bit of sound, so they would not be the ideal partner for late-night listening next to someone.

The headband on the Dekoni Cobalt headphones offers a good level of comfort

SOUND

For the first part of this review I left the Fenestrated sheepskin earpads on the Cobalt. There are two qualities that are immediately apparent on the Dekoni, and those are detail retrieval and the soundstaging, both of which are excellent.

The Dekoni Cobalt are not designed for those who want a healthy dose of bass added to their music, these are a very controlled pair of headphones that aim to present the bass in a more honest way. They are, however, not lacking in depth and extension, playing Leftfields Melt for example really shows the quality of bass on offer. The deep bass notes sound full and engaging providing a solid foundation to the song, whilst the synths are allowed an impressive amount of space to float around the mix with great accuracy.

These, however, for me, are all about the midrange and the way they cut through the mix with excellent clarity. They are a slightly mid-forward-sounding pair of headphones, which means vocals and guitars never get lost in the mix; they are not, however, overly dry or analytical in terms of their presentation and I found myself really listening to the lyrics of the tracks I played through them. Beautiful Bodies – September 1973 is a track I’ve listened to many times, yet with the Cobalt I “got” the lyrics. Allowing me to hear every single word, the Dekoni’s inspired me to find out what the song was written about – this to me is testament to how they make you appreciate songs with deeper meaning.

The cable included is detachable

Putting on something heavier, Like Moths to Flames, I found the Cobalt did lack a bit of impact to really grip the recording and deliver it with the energy required; these would not be my first pick for heavy music. Buena Vista Social Club happened to pop up next though and this kind of music really highlights the Cobalt’s strengths in terms of separation, accurate stereo imaging, huge soundstage for a closed-back headphone, and the overall balance of the sound. The piano sounds just right, keeping you engaged whilst you listen out the for subtleties in the recording and imagining yourself there in the room with the musicians. It’s no secret that I’m a sucker for female vocals, and Gabrielle Aplin sounds absolutely stunning through the Cobalt – every breath, every little detail audible, with tons of space to separate the different elements in the recording.

Less-than-perfect recordings can come across a little brash and there is a slight steely quality to the upper midrange/lower treble that can sound a little grating with certain songs. The Cobalt are not what I would call a natural choice as an all-rounder, but if you have a good collection of headphones they easily fit in and work extremely well with the right music. They could sound a little fatiguing to some and there is a slight thinness to the sound that makes them unsuitable for general mixed listening at times, but put on some vocal, acoustic, jazz, soft rock, or chilled-out electronica and they are incredibly enjoyable.

VELOUR EARPADS COMPARISON

Now let’s try out the Elite Velour earpads that are included with these. The earpads are not the easiest to remove and the clips can be a little fragile which isn’t ideal, but, then again, I don’t see people rolling earpads on these very often.

Personally, I prefer the feel of Velour over Leather, however, the Fenestrated leather pads are very comfortable. The sound on the other hand becomes less rich and thinner than with the Fenestrated Sheepskin and I can’t find this particular sound signature working for most people, and you can tell the cans have been tuned with the Fenestrated earpads in mind.

The bass is less articulate and the vocals take a step back and they sound more distant with the Velour earpads. There is a dip that makes the upper midrange a little less forward, but the trade-offs in body and lower midrange presence don’t make too much sense unless you only listen to well-recorded acoustic and jazz.

I understand that Dekoni wanted to give people the chance to have two different sound signatures by including the different earpads, but they do only work with specific genres and personally, I would leave the Fenestrated Sheepskin pads installed.

CONCLUSION

The Dekoni Cobalt are not neutral headphones and they’re not tuned for absolute accuracy, however, they have a dynamic and articulate sound that is slightly mid-forward and works well with music that relies on a good midrange (A lot of audiophile music fulfills this definition). They don’t have particularly impressive slam or punch, yet they dig deep when called for and there is a wide and deep soundstage that contributes to excellent space and separation.

These are not a natural all-rounder, yet they would easily fit into a headphone collection and bring an excellent listening experience when using the right music. I found female vocals, acoustic and chill-out electronica to be particularly enjoyable.

I am awarding these four hearts with the caveat that they are not an all-round headphone and they are best suited to certain genres of headphones. If you listen to these genres as outlined in the review, then I recommend you give these a listen as they are very good!

AT A GLANCE

Build Quality:

A lightweight mixture of plastic and metal that is well finished

Sound Quality:

Slightly mid-forward with great sounstaging

Detailed, but occasionally a little thin

Value For Money:

For the price you do get a well-tuned, closed-back headphone that sounds excellent with the right music

We Loved:

The clarity, separation, and midrange presentation

We Didn’t Love So Much:

They can sound a little thin, borderline harsh at times

Elevator Pitch Review: The Dekoni Cobalt are excellent for listening to acoustic and more laid-back music, bringing focus to vocals and guitars. They would make an excellent addition to an existing headphone collection, providing an impressive level of detail and a spacious soundstage

Price:  £499

Oscar Stewart

SUPPLIED BY ELECTROMOD

Review Kit: JDS Labs Atom DAC+ / Van Damme interconnects / Singxer SA-1 / iFi Go Link