Drop Ether CX Review (Closed Planar Headphone)

[solderdude]

Totally off topic..
Seeing as this is Audio Science Review, it would be remiss not to point out that heat doesn't rise.

Hot air rises.

You rose to the occasion to blow some hot air into this topic ?

 

[vkvedam]

I did that a few months ago- the exchange rate is slightly in our favour at the minute but shipping, import VAT and fees are a killer. IMO worth it but YMMV- the RT is killer value.

Well, we might be travelling to the US if things don't go haywire from here and I shall bring those with me

 

[Jimbob54]

First, thanks for the review, @amirm!

EDIT: I saw a lot of requests for an Noire, A2 Open, and RT Open, we'll send them to Amir, no point making a user send a unit.

The most obvious difference between the open and closed Aeons is the upper bass, A2 Open has a "bigger" bass sound (admit I particularly like this for EDM).

As a general comment on measurements; when I started the company we had very poor gear and the very first thing we did when cash flow allowed it was invest in the GRAS.

We actually mostly voice by ear and use measurements to verify and reproduce what we hear, but we start by ensuring the core technical parameters line up before we voice, so we only build the rest of the system up once we have a foundation of low THD and dood time and frequency domain behavior.



Different driver architecture gives the Ether class an output advantage. Not enough space to apply the same architecture in AEON, plus that's part of the cost reduction, we traded some efficiency in AEON to avoid degrading driver performance.



We will send one. I meant to and forgot...


We no longer sell the ETHER C that was the basis for the Drop product. The ETHER C Flow has an enhanced motor design, and a lot more bass.



I've actually come to focus on listening to acoustic sweeps and tones to assess linearity, and found that perceptually this is kind of close to the Harman curve, but not quite the same. From this I've kind of evolved to a curve that's got more bass, as all our more recent products suggest.

The exception is VOCE, but we did work to rebalance the midrange and highs to sound more linear with a flatter measured response, VOCE sounds way better than bumping the bass, I suspect there's something going on there due to the 88mm driver and how it couples but this is just a guess.



That statement relates to the ETHER C, not the Drop ETHER C. As noted, the Drop version retuned it and modified pads as well, the Drop ETHER C is a definite upgrade to the original ETHER C and closer to C Flow in many respects except bass output and soundstage where C Flow does a better job, at least without EQ.



That's not quite correct... Bruce was very generous in answering questions we had when we started out and one of his answers sparked the idea that led to our v-planar patent. Because I wouldn't have had the idea without some past research he'd done and a prior patent he explained to us, we wouldn't have had the idea for v-planar. As without his generosity and deep expertise we wouldn't have had the idea, we felt he was part of the team and added him to the patent. He's just a super guy at every level, it was a real treat to get a chance to talk to such a great engineer.

Many thanks for the clarification.

 

[oesu]

@amirm

Thank you for the review! I was hoping you'd find a time for these. I really like them and was curious how they measure.

Did you use any of the included filters when measuring?

@Dan Clark
Thanks for making these headphones. Do you know how will the sound change with angled Ether pads?

 

[Dan Clark]

@Dan Clark
Thanks for making these headphones. Do you know how will the sound change with angled Ether pads?[/QUOTE]

Yes... I'd have to measure it, don't remember the exact change. I'll try to do this early next week but if memory serves it adds a little in the upper midrange or lower treble region.

 

[oesu]

@Dan Clark
Thanks for making these headphones. Do you know how will the sound change with angled Ether pads?

Yes... I'd have to measure it, don't remember the exact change. I'll try to do this early next week but if memory serves it adds a little in the upper midrange or lower treble region.

Thank you

 

[DanTheMan]

It's so nice to see well engineered headphones that aren't intended to be sold to the masses. These are definitely for the enthusiast. I have the Mad Dog 3 I believe and while they are good, they are not this good.

 

[amirm]

@amirm and All,

That GRAS 45CA on your bench is also made to test hearing protection devices; ear plugs and ear muffs.

Will you test the isolation of this set of closed back headphones and show us the attenuation vs. frequency plots?

Thanks DT

You need an isolation box which I don't have room for.

 

[Helicopter]

You rose to the occasion to blow some hot air into this topic ?

Perhaps Amir should indicate the tests are done here in Earth's biosphere, where there's, you know, air.

 

[respice finem]

and test the influence of rising CO2 levels... (insert clown icon here)

 

[Acerun]

Dont disagree but I have never actually had a bad Drop experience. If it was only saving $100 or so I wouldnt even think it was worth it for reasons you mentioned, but I got these on offer for $750. A no brainer.

I got mine on eBay in perfect condition for $675 shipped with a extra pair of ZMF pads and an extra Ninja Audio cable. The deals are out there.

 

[DualTriode]

You need an isolation box which I don't have room for.

@amirm ,

No isolation box, no problem.

You Test headphones without an isolation box.

You test hearing protection the same way you test respirators, inside the device and outside the device and compare the measurements.

Procedure:

Hook up your 45CA on the bench or as you usually do.

Hook up the output of your 555 generator to your test amplifier and test speaker (calibrate the test SPL as needed)

Run the test with the test 45CA without the headphones in place and save the results.

Run the test sweep again with the headphones in place on the 45CA. (The cord may be removed from the headphones.)

The difference between the measurements is the isolation provided by the headphones.

This you can do right there in your loft/lab just like testing headphones without an isolation box.

Thanks DT

 

[richard12511]

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/

Dan Clark seems to make consistently great headphones, which seems to be really rare in the headphone space.

 

[richard12511]

Dan Clark makes some excellent headphones and is truly pioneering.

Agreed.

In comparison to loudspeakers, most headphones seem to measure kinda bad. Given just how much more effort and money there is going towards headphones, that tells me that making great, neutral, and low distortion headphones is a much tougher task than doing the same with loudspeakers. The fact that Dan seems to consistently produce top performance/price headphones is really impressive and refreshing.

 

[amirm]

The difference between the measurements is the isolation provided by the headphones.

Only if ambient noise stays constant which is not something you can count on in residential setting. In addition, noise spectrum won't be flat so you will not very accurate results.

 

[Robbo99999]

Only if ambient noise stays constant which is not something you can count on in residential setting. In addition, noise spectrum won't be flat so you will not very accurate results.

You could maybe do multiple measurements and then average them before comparing the differences - to reduce the effect of random changeable outside noise. You might also be able to identify the sweeps that had the excessive outside noise influence by their virtue of being outliers at certain places on the frequency response - at which point you could discount those sweeps from the average.

 

[DualTriode]

Only if ambient noise stays constant which is not something you can count on in residential setting. In addition, noise spectrum won't be flat so you will not very accurate results.

@amirm,

This is a rousing game of yes but.

The same arguments apply to testing headphones without an isolation box.

Thanks DT

 

[jae]

First, thanks for the review, @amirm!

EDIT: I saw a lot of requests for an Noire, A2 Open, and RT Open, we'll send them to Amir, no point making a user send a unit.

Glad to see it, hopefully E2 could sneak on that list as well (unless you're planning on releasing something new to replace it ).

If you have the means to measure and they are obviously measuring well, why not provide that info on the product information page along with the specs? The way I see it, it wouldn't change the opinions of people that don't care about measurements but would only serve to make those that care about it more confident in buying.

Most people on here already know the general FRs of most headphones due to the work of oratory1990, crinacle, etc, so amir's measurements here just provide another set of data. We already know how close existing headphones will score relative to harman (although fresh measurements never hurt), but the distortion measurements are new for a lot of people and the main takeaway for me from these reviews. While people may have their own subjective desires for a certain FR, I don't think anyone is going to complain about objectively low distortion.

 

[Remlab]

What I admire about most about Dan Clark, is that he took his obsessive diy hobby and turned it into this amazingly successful business. He is definitely the Yoda of Planar Magnetic headphones.

 

[Dan Clark]

Glad to see it, hopefully E2 could sneak on that list as well (unless you're planning on releasing something new to replace it ).

If you have the means to measure and they are obviously measuring well, why not provide that info on the product information page along with the specs? The way I see it, it wouldn't change the opinions of people that don't care about measurements but would only serve to make those that care about it more confident in buying.

Most people on here already know the general FRs of most headphones due to the work of oratory1990, crinacle, etc, so amir's measurements here just provide another set of data. We already know how close existing headphones will score relative to harman (although fresh measurements never hurt), but the distortion measurements are new for a lot of people and the main takeaway for me from these reviews. While people may have their own subjective desires for a certain FR, I don't think anyone is going to complain about objectively low distortion.

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.

What I admire about most about Dan Clark, is that he took his obsessive diy hobby and turned it into this amazingly successful business. He is definitely the Yoda of Planar Magnetic headphones.

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

And thanks...