Dekoni X HiFiMAN Cobalt Review

Dekoni X HiFiMAN Cobalt Review

At this year’s CanJam in NYC, the new closed-back headphone from Dekoni and HiFiMAN was on the show floor. Since then, I’ve been waiting to get my hands on it and spend some more significant time with it. A partnership between Dekoni and HiFiMAN is an interesting prospect, and I’m excited to see what the results are. The Cobalt is what we have, and it was officially released back in March for $499.

Dekoni X HiFiMAN Cobalt items

What You Get

  • Dekoni Elite Fenestrated Sheepskin (Balanced) Earpads
  • Dekoni Elite Velour (Analytical) Earpads
  • Gold Plated 3.5mm Female to 6.35mm Male Adapter

Dekoni X HiFiMAN Cobalt headband

Look & Feel

Everything about the frame of the Cobalt makes it recognizable as a HiFiMAN headphone. The headband and yokes have been seen on other HiFiMAN headphones like the Edition XS and HE-R9. I’m not the biggest fan of these parts, as I find them a bit too flimsy. This doesn’t effect the comfort of the headphones though, as the ear cups are quite big and have these large ear pads. Of course, Dekoni is able to supply the Cobalt with proper ear pads, and two sets are offered here. I prefer the standard sheepskin pads over the velour both for feel and sound.

Dekoni X HiFiMAN Cobalt above


Housed within the Cobalt is a 45mm dynamic driver with carbon-coated diaphragms. It is recommended that you use some kind of dongle or outboard DAC with these headphones but it isn’t necessary to achieve ample loudness.

Dekoni X HiFiMAN Cobalt side


I’ve heard a few people say that the Cobalt is a very open-sounding closed-back headphone, and I think that characterized the soundstage well. It engulfs a ton of headspace, and spatial imaging has a ton of depth. It is extremely wide for a closed-back headphone and communicates a ton of separation in between all its elements. You feel it leak out past the ear cups, and wrap around you in a larger headspace. There is a ton of space that the Cobalt has to show, positioning sounds around you almost like in a dome. Ambient tracks showcase this particularly well, establishing the airy qualities of the Cobalt in an immersive way. It paints a sonic environment that goes beyond traditional stereo patterns, and envelopes you in one of the best closed-back soundstages I’ve heard in quite some time.

Low End

While there is definitely a bass presence to the Cobalt, it isn’t put into much focus. You won’t get a lot of vibration or rumble from the lows, with minimal sub-bass response to be found. Most of what you’ll find is a neutral mid-bass that can hit hard at times, but remains as a soft tone. Due to the great soundstage and imaging, the Cobalt brings no muddiness or bleed. All the frequencies you need are spaced out in an identifiable way, making some details stick out. In the track “It Moves Swiftly Forward, Throwing Up Great Waves” by Jan Jelinek, there is even a concentrated bloom of bass that caused the most vibration I could get out of the Cobalt. It was one of the few instances where the Cobalt had texture to the lows, and it was very smooth. However, responses like this are few and far between.


The midrange of the Cobalt has its strengths, and remains quite clean for the most part. You don’t get much from the low-mids, but the upper-mids showcase a ton of emphasis. Instruments have a good amount of room in the mids, and it makes displaying defined performances one of the Cobalt’s best attributes. Individual notes can have a strong hit to them, and it makes the midrange appear much more detailed. Vocals are presented clearly as well, and although they aren’t as cutting as other headphones, they still posses a powerful drive with tons of expression.


A lot of the focus in this sound signature is relegated to the highs. If you had to single out one characteristic of the Cobalt to sum up its timbre, it would be its brightness. The highs come forward the most out of any region of the frequency response, leading to varying qualities. Some might find the texture here a little too harsh, but it never bothered me too much. It has some edge to it, and some frequencies can get quite hot, but it’s all easy to digest for me. If you can get past that, then the Cobalt has a lot of colorful details to show you, leading to an enjoyable response.


I’m usually not a big fan of HiFiMAN’s closed-back headphones, but the Cobalt is a very solid effort. For their first collaboration with Dekoni, I think the results are favorable, especially with the impressive soundstage and imaging. This is a very bright headphone, but never to a degree that is detrimental to the experience of the sound. The price might be a bit much for what the build is, but I think if you want the best soundstage possible for a closed-back headphone, the Cobalt might be the best choice.

Pros ConsĀ 
  • Wide soundstage
  • Holographic imagingĀ 
  • Defined midrange
  • Bright but detailed highs
  • Comfortable ear pads
  • Weak bass
  • Flimsy structure

The Dekoni X HiFiMAN Cobalt is available at Audio46.

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Alex S. is a sound designer and voice-over artist who has worked in film, commercials, and podcasts. He loves horror movies and emo music.