Dekoni Blue

Dekoni Blue is a modification of the Fostex T50RP MK3, which is the only mod of this model officially approved by Fostex. The price is set at $299, but right now you can get them for $249.

Dekoni Blue is a modification of the Fostex T50RP MK3, which is the only mod of this model officially approved by Fostex. The price is set at $299, but right now you can get them for $249.


Dekoni has been around for quite some time now, offering the best aftermarket earpads on the market. Then an idea came – let’s create something different than the earpads – and that’s how the Blue came to life.

As I said in the beginning, this is the only modification of T50RP that has been officially approved by Fostex.



The unboxing experience of the Dekoni Blue is very simple and modest. All you’ll find is the box, headphones, and the cable with an adapter. The box is pretty ordinary, but it has a great color and cool esthetics, making it a good looking addition for your shelf.

I really can’t say anything else, this is very basic and gets the job done, but don’t expect a fascinating experience while getting these out of the box.


The cable included in the box is 2m long and it has a 6.3mm jack connector, but you’re getting a 3.5mm adapter in the box. The plug going into the headphones is an angled connector with a locking mechanism. While it’s great for security, it is too hard to unplug. You basically have to pull the cable really hard, which may cause problems in the long-term, so I recommend not to unplug the cable too often.

Other than that, it’s a pretty ordinary, black and rather thick cable that is not great, but not terrible either. It gets the job done, doesn’t really get in the way, but it surely won’t impress anybody.

The cable is pretty standard..

Build quality and comfort

As you should have expected from Dekoni – the earpads are absolutely stunning.

Now into some great things – these are fantastically made. I’m digging the blue color of the earcups, with that contrasty orange “Fostex” written on the headband.
Even though the majority of the headphone is made of plastic, it feels robust and very reliable. If you’re looking for a pair of headphones that you won’t have to really care about, I don’t think you can find anything significantly better.

As far as comfort is concerned – these are some of the most comfortable closed-back headphones I’ve ever used in my life. The included Elite hybrid earpads are super plushy, superb to the touch and quite simply the best earpads included with a pair of headphones ever. Dekoni is known for their earpads, so this shouldn’t really surprise anybody.

The Blue is not the lightest headphone around, nor it is the heaviest, but I find the weight to be just right. Clamping force is moderate to strong out of the box, but thanks to those extraordinary earpads it only helps with a great and secure fit, not causing any problems with the comfort whatsoever.



Dekoni Blue is a modified Fostex T50RP MK3, and it’s a true modification, rather than completely changing the original. What’s changed you’ll ask?

For sure the first that you can see is the changed design, with that gorgeous blue color on the earcups. I believe that it’s a great change from a rather boring and plain original.
Other than that, the only two things that have been changed are the earpads and the inner baffle being redesigned. As far as the earpads go, you know my opinion already – these are absolutely mind-blowing.
The inner baffle on the other hand has been changed to switch the tonality a bit, creating a more personalized headphone by Dekoni.


Studio heritage, made for an effortless experience.

I’ll start this part by saying, that if you’re looking for an absolutely best all-rounder and the best bang for your buck headphone in this price range, Dekoni Blue definitely isn’t that. In terms of raw technical performance and being universally tuned, the Hifiman Deva is a much better product for you.

The bass is definitely the star of the show, and you’ll hear it from the first moment. It’s big, rounded and very forward. Bassheads are going to be quite pleased, but I strongly recommend plugging those into a strong amplifier, as it helps to tighten up the low frequencies a lot. Other than that, the bass is addictive, strong and just fun to listen to, but nowhere natural or neutral. Put some Post Malone or any electronic music into them though, and you’ll be in for a treat.
What’s surprised me the most, was that the bass is more reminiscent of a dynamic driver construction, providing a great punch and physicality, which is rather rare for planar magnetic headphones.

Fostex T50RP has been around for a while now.

The midrange is yet again – very pleasing. It is warm, lush and smooth with a hint of energy in the higher region. Thanks to that, these are great for long listening sessions, where you’ll really appreciate the fantastic comfort and this very smooth, easy tone of the Blue.
While not the most detailed pair of headphones out there (well, not even close to being close), those are great to just sit, relax and listen to some music without paying too much attention to what you’re hearing. I tend to reach out for them after listening to my Hifiman Ananda, which is a detail monster, with a much more focus on the classic “audiophile” qualities in music.

The treble is yet again rather smooth and clean, with just a touch of spiciness to it. While I won’t describe the Blue as dark sounding, it is noticeably calmer and less detailed than any of my other headphones. That makes it a great companion for long listening sessions once again.
Don’t get me wrong though – these are not muffled. The treble region focuses more on a smooth and pleasing approach with a moderate detail retrieval, but I won’t call it withdrawn by any means. There’s still sparkliness to it, and there’s actually one thing that the Dekoni Blue is great at – recreating the timbre of the cymbals. They somehow can easily reproduce this thick, bold and rich sound that is fast and clean at the same time – that’s impressive.

I absolutely love the color.

The soundstage is quite surprising actually. While being narrow and condensed, it has an impressive depth to it with excellent imaging. The fact that it’s narrow isn’t really weird – it’s a closed-back headphone at the end of the day. But it’s a rather interesting feeling, having all the sounds really close to you when left and right is concerned, with a really good depth towards you.
Of course, it doesn’t sound as open and airy as open-back offerings, but having only closed-back headphones in mind, I’d actually call the Blue’s soundstage great.

To summarize – Dekoni Blue is a great secondary headphone to have in your arsenal. While it’s not universal when it comes to tuning, it provides a fun, fatigue-free and very comfortable listening experience that is easy to appreciate.


Dekoni Blue is easy to like, and it won’t kill your wallet.

The legend is alive. Dekoni Blue is a very good modification of the vastly popular T50RP by Fostex, providing a great build quality, comfort, and that smooth, easy tone. If you have a good, neutral open-back headphone for your daily use but you’re looking for a secondary pair that’ll give you a chill and easy time with your music, the Dekoni Blue is a good choice.

Gear used during this review for the sake of comparison and as an accompanying equipment:

  • Headphones – Hifiman Ananda, Hifiman HE400i 2020, Hifiman Deva, AKG K501, Audeze LCD3
  • Sources– Cayin N3Pro, Cayin N6ii, JDSLabs Atom stack, SMSL SU-9 + SH-9, Feliks Audio Echo MK II