REVIEW / MEASUREMENTS: Dekoni Blue ("Approved" Fostex T50RP Mk 3 mod). And the importance of the room for hi-fi reviews (Wilson Chronosonic XVX speakers in Stereophile).

As you can see in the image above and might know already, these are essentially Fostex T50RP Mk 3 headphones which have been out since 2015. In 2018, the Dekoni company (which makes aftermarket headphone pads and accessories mainly) decided to make a licensed version of the Fostex with their own earpads and blue esthetics - hence the Dekoni Blue (~US$250). If you want a little more background, here's Dekoni's "Short Essay..." on the product.

If you've used Fostex headphones before, I think you'll appreciate that the stock ear pads are thin and rather uncomfortable so upgraded earpads are mandatory for long-term use. When I got these, it was less expensive that a new Fostex + upgraded earpads.

In the box, the product comes with the standard Fostex wires which are a little stiff and there are 2 pairs of Dekoni earpads, the "Elite Hybrid" which are installed on the headphones by default, and the "Elite Velour" as an alternate you can put on.

As usual with the Fostex T50RP, the headphone cable has a locking 3.5mm 90° TRS connector on one end (left ear cup). You can see the locking plastic nub in the image below:

I know people have criticized the stock plastic cables. Yeah, not the nicest cable I've ever seen but it's non-microphonic, gold plated, and the ~6' length is good for me on the computer desktop. Many Fostex users like the V-Moda cable with 45° angle as an alternative. 

Here are the 2 sets of earpads. The default attached Elite Hybrid is angled whereas the Velour is a flat pad - both with reasonably large cavity for the ears. Both are quite comfortable with thick memory foam. You can see the shiny sheepskin on the outside of the Hybrid with fenestrated sheepskin inside.

Just in case you're unclear. The thinner part of the Hybrid pad is at the front of the ear so the driver is tapered inward medially when worn.

My preference for comfort was actually the Elite Velour earpads (I hear that they stopped shipping the new Blues with these?). I found them to fit my ears better with what seemed like a slightly larger size opening. However for soundstage and "outside the head" perception, the angulation of the Hybrid helped make the sound more like it's coming from the front (like the angulation of the Sennheiser HD800). I didn't have any issues like warmth or sweating with either. Here's the planar magnetic driver (Fostex calls it the RP "Regular Phase" driver) exposed when doing the pad switch:

Notice the foam baffle surround basically resting in the ear cup and around the driver. The drivers in these Fostex headphones are relatively small compared to many planar magnetic headphones these days, measuring around 1" x 1.25"; or ~1.5" (~40mm) diagonally. Compare this to some of the more recent planar magnetics like the Monolith M1060 with specs of 106mm (4.2") drivers, or even their lower end Monolith M570 with 97mmx76mm (3.8"x3") drivers.

Admittedly, these Fostex cans are not going to be winning any beauty contests in the headphone pageant but looks are a subjective thing:

Yup, while not the best DAC, for the money, the inexpensive SMSL M100 Mk II is all I need knowing the distortion and noise levels in the rest of the audio chain!

Construction is plastic except for the metal earcup slider for size adjustment. There's a slack wire connecting the right earcup to the left where the locking cable comes in from your amp. The light blue color will be a matter of preference. It's certainly distinctive compared to the more typical black / white / silver.

Comfort is pretty good for me. The earphones are relatively light (330gm without cable) and assuming you don't have an extra-large head, clamping force is fine for average head sizes I think. The main comfort issue is with the moderately padded headband. I could feel some pressure spots over time that can be relieved with a little shifting. Not a problem listening to music for hours. I see that Dekoni sells their Audio Nuggets for pressure relief if needed.

As you can see in the pictures, the L and R designations are on the lower outside earcup. I might put some red and blue tape over the Fostex name to make it easier to identify the sides at a glance.

Here is the measurement summary for these headphones with the stock default "Elite Hybrid" earpads out of the box:

Note: The waterfall plot showing R channel.

As you can see, the frequency response indeed has a bit of a "V" ("U") shape with accentuated bass hump at 100Hz and elevated "brilliance" above 6kHz. The drivers are not as precisely balanced as the Sennheiser headphones discussed last week, but still not bad, not really an issue when listening to music.

Electrical impedance is very flat (I've accentuated the graph to just 10Ω on the Y-axis to show the peak at 93Hz); basically the impedance ranges within a tiny amount from 50.5-52Ω across the audible frequencies! Phase is flat. Even with higher impedance headphone amps, there should not be much fluctuation in the frequency response.

The 10ms, 40dB range waterfall graph is not great in that there's still quite a bit of residual energy below 1kHz over 10ms. Given the relatively large hollow headphone cups, at least some of this is likely the result of cup resonance. Harmonic distortion at around 95dB SPL is still <1% except in the bass below 40Hz. Distortion is a bit higher than the "standard" AKG K371 headphone previously measured or the Sennheisers last week. As usual, I don't believe humans are all that sensitive to harmonic distortion so no worries IMO below 1% like this.

Switching out earpads then, here is the summary diagram with the "Elite Velour" which as I mentioned above are the pads I preferred:

Note: The waterfall plot showing R channel.

With these pads on, I measured the voltage sensitivity. Like the Fostex T50RP Mk 3 these are based on, they're rather insensitive headphones. Notice the 0.25Vrms 1kHz signal measures only a low 89dB SPL. This means we're looking at 101dB SPL/V (this works out to an efficiency of 88dB/mW, the official Fostex T50RP Mk 3 sensitivity spec is reportedly 92dB/mW). Compounded with a low-medium impedance of 50Ω, I would highly recommend pairing these with a powerful headphone amplifier like the Drop + THX AAA 789 (the +10dB gain setting will be useful). Portable electronics like smartphones, tablets, laptops just are not going to work well especially if you want to experience the bass on these headphones.

The main difference between the pads is that the Velour is less bassy compared to the Hybrid. We can see the difference if we overlay the frequency responses (average of left and right), using 1kHz as the reference amplitude:

There might be a slight accentuation of the treble with the Velour pads but I didn't find this as consistent or noticeable as the lower bass. At 100Hz, the Hybrid pads have a +1.8dB accentuation over the Velour. I have read some people describing the Dekoni Blue sound as "dark". Certainly not to me; these are nothing like the "darkness" of the HD650 discussed last week.

The Fostex T50RP Mk 3 is described as a "semi-open" headphone. It's just slightly different compared to the T40RP ("closed") and T20RP ("open") - all the same price. The only difference as far as I am aware is the density of the foam behind the vent above the L/R label. The Dekoni Blue (T50RP) will have a "semi-open", semi-dense black foam behind those horizontal vents:

Isolation isn't great:

Notice that the outside noise is unattenuated until around 900Hz. By 5kHz, the attenuation is around -18dB which makes it a bit better than the Sennheiser HD650 (and significantly better than the HD800). You'll still hear most of what's happening around you with some muffling of upper mid and treble sounds.

The sound leakage is quite full-spectrum and again better than the "open" Sennheiser HD650 and HD800 headphones:

That's an average of 64dB SPL between 100Hz to 10kHz measured at 1" behind the headphone vent, the loudest part of the leakage. This works out to 42dB SPL at 1' - compare this to 33dB SPL @ 1' for the AKG K371, 61.5dB @ 1' Sennheiser HD650, and 67dB @ 1' Sennheiser HD800. The slight down-sloping average amplitude line indicates that the leakage will tend to sound tonally more mid-range than bright (unlike the Sennheisers).

Finally, let's have a quick peek at the impulse response:

Looks about the same in terms of the general morphology of and duration of the waves with either earpad. No surprise since the frequency response did not change too much. Alas, I had started modding the headphones and neglected to capture the 100Hz square waves; we'll look at this another time.

So how do these sound?

Yeah, the "V" frequency response is quite obvious. The bass is strong and IMO overpowering especially with the default Elite Hybrid earpads. Coming from say a Sennheiser HD800 to this, the bass on the John Wick OST and Malia/Boris Blank's Convergence gave me a mild headache after 30 minutes! I listened for a few days then decided to switch over to the Elite Velour pads which were a bit better but I still felt the bass bump was too heavy. Clearly each listener will have his/her own preference. Listening to This Is Dubstep Anthems with these headphones was quite an experience and the track "Adrenaline" lived up to the name.

The other part of the "V" curve is the accentuated treble which didn't bother me as much, perhaps because I'm used to the inherent brightness of the Sennheiser HD800. The guitar work on Los Angeles Guitar Quartet's LAGQ Latin was clean, precise, had tons of detail. The natural reverb of each note was rendered with a nice "air" around the instrument. Plenty of subtle nuances coming through with a good, wide soundstage. It's not subjectively as spatially "large" of a sound compared to my Sennheiser HD800 but with the comfortable soft and deep earcups, it sounds more spacious than closed headphones like the AKG K371 that confines most of the sound except hard L/R pans to a narrower space inside the headspace.

Overall, I think these are good headphones for rock. Loved Saskatchewan-born Colin James' eponymous album from 1988, DR13. Although the mix/mastering isn't the most detailed or cleanest, the Dekoni Blue retrieved the music masterfully. Punchy drums, excellent retrieval of the details in the mix even during some of the "thick", congested portions of songs like "Five Long Years". Wonderful energy on tracks like "Chicks 'n Cars (And the Third World War)" and the sweet ballad of "Dream Of Satin" sounded great as the song transitions from slow/sentimental '80s sax-pop to percussion rock/pop portions. The tonality of this album has a tendency to be mid-range heavy; a more "V"-shaped frequency response like with these cans enhanced the excitement (great example is the guitar solo on "Why'd You Lie?"). 

One unexpected surprise I had was just how well these headphones played binaural audio! The classic YouTube video "Virtual Barber Shop" which I mentioned last time with the HD650 sounded remarkably natural and "3D" through these, the extra bass "body" added to the sense of realism over the HD650. The expansiveness of Explorations in Space and Time (Chesky, 2011), also a binaural recording, was simply excellent and the realism of "Wood and Metal" was at times eerie with me checking a couple times to make sure I wasn't hearing my wife or kids making noises in the other room. The subsequent track "War" is a nice test of how well the headphone is able to separate instruments in the soundfield as drums, xylophone (?), cymbals, among other instruments at times swirled around with a sense of vertical height to the instrument placement. Compared to this, typical audiophile female vocals like Norah Jones and Diana Krall just didn't seem as challenging to reproduce. ;-)

Let's wrap up...

While I have more headphones than I really need, a reason I bought these was because I liked how the Fostex RP family sounded back in RMAF 2019. Here's a picture from the headphone area of the show where I had a listen to the T50RP Mk 3 and Fostex T60RP:

After the show, I made a note to at least grab the T50RP when I had a chance because I was impressed by what I heard given the asking price (even though the earpads did not impress). The T60RP sounded very good and tempting with that beautiful mahogany sculpted earcup, but knowing that there was a large "modding" community, and the likelihood that at some point I would open the thing up, I figured that something like this Dekoni Blue was overall a better deal if I could find it at a good price with the 2 pairs of earpads.

I was tempted by some of the larger-driver, open planar magnetic headphones like the Monoliths I briefly noted above (or maybe the Hifiman Sundara). However, I already have fantastic-sounding open headphones in the form of the Sennheiser HD800 and AKG Q701 so aiming for "balance", the semi-open Dekoni/Fostex was more interesting and at a lower price. When it comes to noise isolation and leakage, it certainly sits in between the open Sennheiser HD650/HD800 and the closed AKG K371 I've already reported on.

Bottom line: While the Dekoni Blue sounds overall quite good, be mindful of that "V"/"U" type of frequency response which will not be to everyone's liking. In particular I personally find the accentuated mid-bass hump (around +9dB at 100Hz with the Elite Hybrid pad) excessive. For the most part, I'll be sticking with the Elite Velour pads. We're not done yet with the Dekoni Blue. Let's open this baby up and see what simple mods we can do to improve performance, along with a few more measurements to document changes in a follow-up post in the next few weeks.

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This past couple of weeks, Wilson Audio's Chronosonic XVX has been making headlines again and Stereophile's recent review by Michael Fremer has been an interesting read. At 6'4" tall, close to 3-feet deep, 1.4' wide, and >680lbs each when assembled, these are serious monsters. The asking price of US$329k is also serious, even for multi-millionaires - comparable to other luxury toys available. Back in the pre-pandemic days of RMAF 2019, I was at the unveiling of the at-that-time static display of the XVX and can attest to the impressive workmanship of the speakers. Whether one likes the look, or if one believes the price tag reflects value is not for me to judge. Maybe at some point in the not-too-distant future, a dealer nearby will have one in for listening at which time I'll happily bring a few CDs over. ;-)

From RMAF 2019. Behind the XVX is the Wilson Subsonic subwoofer: 3-drivers, front-ported, passive. Price $40k. 5' tall, 600lbs.

I found it interesting reading a comment on Fremer's review by justanotherhifienthusiast on Steve Hoffman Music Forums and the discussion that followed. I think that the OP certainly makes a valid observation. Basically: (and I'm paraphrasing) "What business does that huge luxury ultra-high-end speaker with an asking price of a third of a million dollars have sitting in that crammed basement?" (See this 2017 video for context.)

It's not unreasonable to wonder if the review conducted in these circumstances might actually be highly inaccurate. Imagine a prospective buyer walking into a showroom like that. Intuitively, would one be impressed that adequate thought was put into the system set-up?

The follow-up questions in the thread are also important... Are we sure the darTZeel NHB-468 monoblocks (apparently Wilson is making a claim about correcting for amplifier group delay, but has not tested the darTZeel) really up to the task of driving a speaker with impedance dipping down below 2Ω at key frequencies like 200-500Hz and 2-3.5kHz, with even lower EPDR? Then there's the question of that strong 50Hz bass resonance, and ~180Hz null in Fremer's room given that he's a professional reviewer who claims to be able to hear exquisite details?

I find it interesting that magazine reviews like these rarely show off pictures of a product like this in the actual room where the listening was conducted. Instead we see manufacturer-supplied stock photos and "model" pictures of unconnected speakers in a generic show home. In a day and age where we have the resources to show pictures and videos easily, that's an inherent lack of transparency. Certainly in 2021, most audiophiles know that the room itself is one of the most important "components" in a sound system and we really do need to spend more time considering and optimizing our soundrooms. Over the years, we have seen Fremer's room as per the 2017 video with the Wilson Alexx speakers in there, already appearing quite imposing in that space. Note that the Wilson Alexx is more than a foot shorter, has 6" less depth, and thinner than the Chronosonic XVX.

Imagine if this was a professional review of other expensive adult toys. Imagine if a flagship digital camera body was tested only with inexpensive consumer zoom lenses. How about the latest high-performance sports car reviewed without even a few hours at a race track? Whether it's some high resolution lenses, or a race track, or a decent sized room that's not forced to have the speakers right against a corner, these are the essential associated conditions for proper evaluation of the device. Conditions which readers can appreciate as doing justice to the spirit of aspirational gear.

I would consider the room as the single most important piece of "associated equipment" essential to get right, commensurate with the price point of the speakers! Only in a well-sorted room can a reviewer convey confidence that the device is truly being used to appreciate the strengths and comment on weaknesses. Seriously, in the absence of a decent room, who cares about all those "Cables" and "Accessories" taking up almost half of the Associated Equipment list?

As speculated in the Steve Hoffman thread, Fremer likely would have been listening to these 6'4" speakers at a "nearfield" distance; here's the XVX manual - notice on page 60-62, the set-up tables start at 8' listening distance; is the listening seat even at least 8' away? Did Wilson design these speakers to be listened like this? Wouldn't this lead to poor integration of the sound from all those drivers (4-way, 7 drivers)? Isn't this important especially given the "Chronosonic" name and the stated intent of the speakers being able to maintain "the synchronicity of the leading edge of each note"?

Hmmm, given the trouble of going through "micrometer" adjustments, notice the absence of any time-domain measurements. A step response from the listening position would have been interesting.

"Audiophiles" speak as if the most important thing they care about is good sound quality. Audiophiles generally want to believe that we come from a legacy of "high fidelity" audio reproduction and companies like Wilson Audio are quick to portray their products as scientifically researched and engineered, made to sound accurate, with all kinds of adjustments down to micrometers, achieving a level of "chronosonic" coherence. But in practice, is Fremer's set-up truly achieving what audiophiles aspire to either broadly in terms of high fidelity, or specifically in this case Wilson Audio's intent? While I appreciate Wilson's drive for excellence especially given their legacy of good products (wonderful evening of listening to the Sasha DAWs a few years back), it's hard to have faith in Michael Fremer's evaluation of the sound of these speakers under such conditions. Likewise, it is hard to imagine people who have money to buy such speakers using it like this.

Fremer writes well and I find that his insights into the music and various pressings can be very interesting at times. His experience with vinyl hardware is also amazing and he should really stick with that strength/niche IMO. Beyond that, as time goes on, given his age, the room, the tendency to use vinyl as source, it's hard to believe in his ability to adjudicate sound quality, particularly for flagship products like this. Certainly Stereophile can use some younger blood among its stable of reviewers.

Seriously folks, was it ever in doubt that these expensive Wilson speakers would have received anything less than stellar reviews from Fremer and Stereophile in general? One last thing... For Fremer to drag his wife and some non-audiophile friend's purported testimonies into the review comes across as silly. At best, this perpetuates old audiophile clichés, at worst it comes across like an insecure plea from a supposedly professional reviewer to "Please love this product - even wives and non-audiophiles do!". Yeah man, sure. 

BTW, I'm wondering about this guy's installation and sonic impressions of the XVX. At least the space appears to be much more reasonable.

Stay safe friends, and hope you're all enjoying the music!

Addendum: Fremer's room - listening seat to Wilson Alexx speakers...