Drop Ether CX Review (Closed Planar Headphone)

[edahl]

Really interested to know how it compares to the Ether C Flow 2!

Also the 820

 

[dorirod]

We have debated this... The problem we run into is that for the general public publishing headphone measurements is confusing because people inherently don't understand headphone measurement profiles unless they hang on the sites that measure a lot of headphones, as you note.

You could you know publish it in a secret link If anything it would help narrow down which models to test (and verify), and might generate more buzz! I know I'm personally considering one of your products for my next purchase, just trying to narrow down which one, and knowing the specs of all of them would certainly help.

 

[Remlab]

We have debated this... The problem we run into is that for the general public publishing headphone measurements is confusing because people inherently don't understand headphone measurement profiles unless they hang on the sites that measure a lot of headphones, as you note.

This is something that even High end audio manufactures can have a lack of understanding with. Several years ago, before he passed, Charles Hansen of Ayre Acoustics entered into a conversation on Innerfidelity about how the headphones we were discussing(Along with Tyll's measurements), and made a comment about the terrible peak it had in the 3khz region on the raw response and was incredulous that we were gushing over it.(I forget the headphone involved, but it was almost perfect in that range). We were like "Um, Ok, how do we respond to this"

 

[edahl]

We have debated this... The problem we run into is that for the general public publishing headphone measurements is confusing because people inherently don't understand headphone measurement profiles unless they hang on the sites that measure a lot of headphones, as you note.

On the other hand, for people who care about measurements it's obviously helpful and as we have worked hard to make products we can be proud of its a plus for us to share with the more technically oriented community. In this instance we use the exact same measurement rig Amir does so anything we do maps to what he'll measure, and would pretty much be easy for anyone on this site to interpret... We'll discuss internally next week.



Headphones build I must. Mwahahaha. Listen you will, or fail you must!

And thanks...

I've found DCA support to be very friendly. Could I expect them to be able to provide these measurements if I email them?

 

[Dan Clark]

This is something that even High end audio manufactures can have a lack of understanding with. Several years ago, before he passed, Charles Hansen of Ayre Acoustics entered into a conversation on Innerfidelity about how the headphones we were discussing(Along with Tyll's measurements), and made a comment about the terrible peak it had in the 3khz region on the raw response and was incredulous that we were gushing over it.(I forget the headphone involved, but it was almost perfect in that range). We were like "Um, Ok, how do we respond to this"

Exactly!

I've found DCA support to be very friendly. Could I expect them to be able to provide these measurements if I email them?

They'd come to me for it.

 

[edahl]

Exactly!



They'd come to me for it.

Well I'm shopping for a closed back, seems like I wouldn't go wrong with these What's the case for the much higher priced Ether C (the new ones, 1500 club price)? I'd love to see the plots

 

[Remlab]

Exactly!

I mean, this is the guy who developed the headphone amplification circuit for the Pono player just a few years previous, so you could imagine our surprise!

 

[Dan Clark]

I've found DCA support to be very friendly. Could I expect them to be able to provide these measurements if I email them?

I looked back and found the answer... CX should not use the ETHER pads, you get a 6K spike and it borks the upper midrange.

Comparing the two CX is smoother in the midrange while C Flow has more bass power, lower distortion, throws a deeper soundstage, and is more revealing. Both handle EQ with ease, C Flow needs a little more up top while CX needs more below.

Oratory's measured response for C Flow looks pretty much like what I'd post and he got a near ruler flat response with the PEQ so go there if you want to see vs the CX data Amir has posted.

One thing that is fun with ETHER C Flow is THD, which is even lower than CX. Here're two plots, brown is the CX at 104dB at 1Khz. This maps pretty well to Amir.

ETHER CX THD, 104dB @1Khz

ETHER CX THD, 104dB @1Khz

The lower THD is the Flow tech working, though as you see it was improving on something that was already pretty good...

Anyhow, stick with the CX pads on the CX and if you want to fiddle with the sound use the tuning inserts or EQ.

 

[Merkurio]

I looked back and found the answer... CX should not use the ETHER pads, you get a 6K spike and it borks the upper midrange.

Comparing the two CX is smoother in the midrange while C Flow has more bass power, lower distortion, throws a deeper soundstage, and is more revealing. Both handle EQ with ease, C Flow needs a little more up top while CX needs more below.

Oratory's measured response for C Flow looks pretty much like what I'd post and he got a near ruler flat response with the PEQ so go there if you want to see vs the CX data Amir has posted.

One thing that is fun with ETHER C Flow is THD, which is even lower than CX. Here're two plots, brown is the CX at 104dB at 1Khz. This maps pretty well to Amir.

ETHER CX THD, 104dB @1Khz
View attachment 138982

ETHER CX THD, 104dB @1Khz
View attachment 138981

The lower THD is the Flow tech working, though as you see it was improving on something that was already pretty good...

Anyhow, stick with the CX pads on the CX and if you want to fiddle with the sound use the tuning inserts or EQ.

Awesome numbers (despite the exaggerated Y axis scale)!

Seeing Flow tech actually working in an objective and demonstrable way (not just as a fancy word for snake oil purposes) is reassuring given the current status of the hobby.

 

[DawgSlaya]

I looked back and found the answer... CX should not use the ETHER pads, you get a 6K spike and it borks the upper midrange.

Comparing the two CX is smoother in the midrange while C Flow has more bass power, lower distortion, throws a deeper soundstage, and is more revealing. Both handle EQ with ease, C Flow needs a little more up top while CX needs more below.

Oratory's measured response for C Flow looks pretty much like what I'd post and he got a near ruler flat response with the PEQ so go there if you want to see vs the CX data Amir has posted.

One thing that is fun with ETHER C Flow is THD, which is even lower than CX. Here're two plots, brown is the CX at 104dB at 1Khz. This maps pretty well to Amir.

ETHER CX THD, 104dB @1Khz
View attachment 138982

ETHER CX THD, 104dB @1Khz
View attachment 138981

The lower THD is the Flow tech working, though as you see it was improving on something that was already pretty good...

Anyhow, stick with the CX pads on the CX and if you want to fiddle with the sound use the tuning inserts or EQ.

I wonder what group delay for the C Flow looks like. Can't seem to find it online.
It makes intuitive sense that the flow tech should help with that, just want to confirm.

 

[Jave]

Any plans to also test the C Flow?

 

[Rottmannash]

Dan, just got the Aeon RT Open's last week and can't find anything objectionable about their build, aesthetic or sound quality. I absolutely love how light they are and can take lots of volume w/o distortion. Haven't tried any EQ yet-enjoying them as is for now. Great job!

 

[Acerun]

What's everyone's opinion about the filters? I've heard the two notch white recommended most. Amir, have you tried the fiters?

 

[Acerun]

Is this white paper sticker/filter supposed to be on the fazers or did the previous owner add it?

 

[amirm]

What's everyone's opinion about the filters? I've heard the two notch white recommended most. Amir, have you tried the fiters?

I have not. I put away the box so didn't even remember they came with them.

 

[Acerun]

I have not. I put away the box so didn't even remember they came with them.

Thanks. I spoke with another member and he said his CX has that paper sticker over the fazers so I'm guessing it's meant to be on there.

 

[Acerun]

Here's the photo that made me question whether that white sticker was supposed to be on there.

 

[Lttlwing16]

We have debated this... The problem we run into is that for the general public publishing headphone measurements is confusing because people inherently don't understand headphone measurement profiles unless they hang on the sites that measure a lot of headphones, as you note.

On the other hand, for people who care about measurements it's obviously helpful and as we have worked hard to make products we can be proud of its a plus for us to share with the more technically oriented community. In this instance we use the exact same measurement rig Amir does so anything we do maps to what he'll measure, and would pretty much be easy for anyone on this site to interpret... We'll discuss internally next week.

I'd love to see the way my Aeon RT's measured with each set of different filter pads. Perhaps you could only make it visible to folks once they've logged in to the site , as to keep it out of the general public's view.

 

[oesu]

I have not. I put away the box so didn't even remember they came with them.

Black foam filter comes preinstalled, did you remove it? Or did you measure the headphones with it?

 

[Maiky76]

This is a review and detailed measurements of the DROP + MRSPEAKERS ETHER CX CLOSED planar headphones (made by Dan Clark Audio for Drop). Company reached out to me a couple of years ago to see if I would review them. At the time I was not testing headphones so said no but that I could use a low impedance headphone to test headphone amps. They offered the Ether CX and that is the main role they have had. Currently the Ether CX costs US $900 from drop.com.

I have been remiss in reviewing these because I have so many loaner headphones to test. Alas, it seems every day someone reaches out to me asking when I will test them so here we are.

The Ether CX has a professional and stylistic look to it with the carbon fiber finish:

View attachment 138605

Two sturdy XLR cables terminate in a 4-pin XLR with supplied adapters to other sockets.

Ether CX is a bit on the heavier side given its large size:

View attachment 138608

I find them comfortable to wear despite the unique rectangular inside cup:

Inside dimensions are 58x38x16 mm (height, width, depth).

The one issue I have with comfort is how hot they wear. Due to generous pad area, they are quite warm to the point where I can't use them during summer. My lab is in the loft so heat rises and forces me to use IEMs for the most part during this time of year.

Note: The measurements you are about to see are made using a standardized Gras 45C. Headphone measurements by definition are approximate and variable so don't be surprised if other measurements even if performed with the same fixtures as mine, differ in end results. Protocols vary such as headband pressure and averaging (which I don't do). As you will see, I confirm the approximate accuracy of the measurements using Equalization and listening tests. Ultimately headphone measurements are less exact than speakers mostly in bass and above a few kilohertz so keep that in mind as you read these tests. If you think you have an exact idea of a headphone performance, you are likely wrong!

I expected difficulty in mating the Ether CX to my measurement rig due to rectangular opening but such was not the case. They fit instantly with little need for adjustments.

Ether CX Measurements
Let's start with our usual frequency response measurements:
View attachment 138609

It was interesting to measure these after two years of using them without such knowledge. It was as relief to see such a well-behaved response that hugs the preference curve above 100 Hz. Below that it is not some wild response either: it is flat which shows an intent to get proper response there, albeit, not fully matching latest research.

Relative response then looks very good:
View attachment 138610

The best news was yet to come in the form of exceptionally low distortion:
View attachment 138611

Even when pushed to 114 dBSPL, this headphone has less distortion than many at 94 dBSPL! We should be used to that with Dan Clark headphones but still nice to see in design after design:

View attachment 138612

Now you know why this is such a powerful tool for testing headphone amplifiers. When I hear distortion, it is almost always the amplifier clipping, not the headphone.

Group delay shows very response other than bass:
View attachment 138613

Impedance is low and flat as expected:

View attachment 138614

So best pay attention to my 32 ohm load testing of headphone amplifiers.

Sensitivity is slightly below average:

View attachment 138615


Drop Ether CX Headphone Listening Tests and Equalization
Out of box tonality his fine but not exciting. So I pulled out the EQ tool to add the needed sub-bass and touch up higher up:
View attachment 138616

The performance was stellar now. Spatial qualities which were non-existent before, showed up now. I would rate it a score B on that front. Sub-bass output post EQ was exceptional producing powerful notes that put a smile on my face.

Conclusions
The Drop Ether CX is a very well engineered headphone. It has vanishingly low distortion and a frequency response that is just missing sub-bass to be a complete presentation. That is easy enough fix as is a bit of treble boosting to improve spatial effects. Once there, you have a very nice closed back headphone which blocks out external noise nicely and produces very clean and faithful performance. Without EQ, it lacks excitement for me to use it but you may be different.

I can recommend the Drop+ Ether CX and strongly so with Equalization.

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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Here are some thoughts about the EQ.

Notes about the EQ design:

• The average L/R is used to calculate the score.
• The resolution is 12 points per octave interpolated from the raw data (provided by @amirm)
• A Genetic Algorithm is used to optimize the EQ.
• The EQ Score is designed to MAXIMIZE the Score WHILE fitting the Harman target curve with a fixed complexity.
  This will avoid weird results if one only optimizes for the Score.
  It will probably flatten the Error regression doing so, the tonal balance should be more neutral.
• The EQs are starting point and may require tuning (certainly at LF).
• The range above 10kHz is usually not EQed unless smooth enough to do so.
• I am using PEQ (PK) as from my experience the definition is more consistent across different DSP/platform implementations than shelves.
• With some HP/amp combo the boosts and preamp gain need to be carefully considered to avoid issues

Good L/R match.

I have generated Two EQ, the APO config file Are attached.

The Target is Harman curve Flat@HF
Score no EQ: 82.9
Score Armirm: 89.7
Score with EQ: 100.3

Drop Ether CX APO EQ Flat@HF 96000Hz
July052021-133312

Preamp: -6 dB

Filter 1: ON PK Fc 45.01 Hz Gain 6.80 dB Q 0.54
Filter 2: ON PK Fc 108.77 Hz Gain -0.92 dB Q 0.19
Filter 3: ON PK Fc 1372.77 Hz Gain -3.12 dB Q 0.91
Filter 4: ON PK Fc 3448.50 Hz Gain 2.34 dB Q 4.92
Filter 5: ON PK Fc 3985.10 Hz Gain -2.81 dB Q 4.92
Filter 6: ON PK Fc 6035.66 Hz Gain 4.27 dB Q 0.25
Filter 7: ON PK Fc 7027.99 Hz Gain -4.06 dB Q 3.94

The Target is Harman curve -1.5dB@HF

Score no EQ: 76.7
Score Armirm: 88.9
Score with EQ: 95.2

Drop Ether CX APO EQ -1.5dB@HF 96000Hz
July052021-131710

Preamp: -6 dB

Filter 1: ON PK Fc 41.00 Hz Gain 6.69 dB Q 0.50
Filter 2: ON PK Fc 96.83 Hz Gain -0.74 dB Q 0.11
Filter 3: ON PK Fc 1252.82 Hz Gain -2.78 dB Q 1.60
Filter 4: ON PK Fc 2872.72 Hz Gain 3.03 dB Q 4.51
Filter 5: ON PK Fc 4998.50 Hz Gain 3.10 dB Q 4.77
Filter 6: ON PK Fc 7027.04 Hz Gain -1.40 dB Q 5.00