Dan Clark Audio AEON 2 Noire Review

[amirm]

As noted by Amir earlier in his comments the customer sent him the Aeon 2 Noire without the included tuning pads. As such, the review really only covered a subset of the system's performance options. It's important to note that the tuning system not only affects the frequency domain, but also THD performance. For most users using the tuning kit is recommended as the tuning of the top octaves may sound bright to those looking for a more neutral or more Harman response.

Thanks. I put a note in the review about the pad and linked to your post here.

 

[juliangst]

I would really like to see measurements for all 8 different combinations of the included dampening pads (my aeons came with white felt, black felt, and black foam).

Doing A/B comparison is not that easy when it takes a few seconds to swap those inserts.

 

[Robbo99999]

I would really like to see measurements for all 8 different combinations of the included dampening pads (my aeons came with white felt, black felt, and black foam).

Doing A/B comparison is not that easy when it takes a few seconds to swap those inserts.

Quite a lot of work, and might be useful if there are audible differences between the combinations, or instead he may already know that various combinations may fall inbetween what he's already shown. @Dan Clark

 

[DJBonoBobo]

As noted by Amir earlier in his comments the customer sent him the Aeon 2 Noire without the included tuning pads. As such, the review really only covered a subset of the system's performance options. It's important to note that the tuning system not only affects the frequency domain, but also THD performance. For most users using the tuning kit is recommended as the tuning of the top octaves may sound bright to those looking for a more neutral or more Harman response.

The following shows the effect of various filters on frequency response. For myself I generally use 1 notch white + 1 black as shown in the blue line. The reason the filters reduce the amplitude of the peaks and sometime valleys is they serve to reduce standing waves. Their ability to do so is limited, which led us to develop our Acoustic Metamaterial to give better control of all aspects of upper octave performance.

View attachment 296338

As is evident, the blue curve is significantly smoother than the no-pads tuning, and is also therefore easier to PEQ, using the following settings:

View attachment 296339

View attachment 296340

Last of all, as noted above the filters significantly reduce THD, including in the lower midrange. This particular unit I pulled from inventory also has a bit less bass THD, but Amir's unit was within norms. Note the reduction in THD around 700Hz.

View attachment 296341

I hope this provides additional insight into both the intended use of the product as well as the performance effects of the tuning system.

Black means black foam or black felt?

 

[Digidigi]

I would really like to see measurements for all 8 different combinations of the included dampening pads (my aeons came with white felt, black felt, and black foam).

Doing A/B comparison is not that easy when it takes a few seconds to swap those inserts.

I'd love to see measurements for different pads as well - especially because the Noire doesn't come with the one-notch whites shown in the graph. (Or at least mine didn't.)

 

[juliangst]

I'd love to see measurements for different pads as well - especially because the Noire doesn't come with the one-notch whites shown in the graph. (Or at least mine didn't.)

Same here. Mine came with a two notch white felt and a one notch black felt and that black thin foam.

Not sure if there is a different between my two notch white felt and that one notch white felt Dan Clark referred to

 

[Dan Clark]

i have to check something to answer a couple of these questions.

 

[JanesJr1]

In a closed back a Planar driver does more to mitigate the issue of FR variability. OTOH open backs will have less FR variability regardless of driver tech, but with the penalty of deficient bass quantity both with dynamic and planar drivers.

Yes .. and with an open back planar, if you're lucky, it tolerates EQ to remedy the bass rolloff. That's one of the reasons I like the open-back Sundara -- I could EQ in some sub-bass and it accepted it effortlessly.

And despite my attraction to clean planar bass, the Sundara does have a little bass resonance going on, and I sometimes like it, especially with bass guitar. It strikes me as a good example of our (in particular, my) residual appreciation of at least some bass distortion as euphonic, as Dan Clark avers.

 

[IAmAlwaysSerious]

The following shows the effect of various filters on frequency response.

Nice graphs, those are. Is there any chance you could provide some for the DCA closed X?

Yep, in my experience it is, the HD560s EQ'd bass is basically as good as the planar HE4XX and closed back NAD HP50 in terms of bass after all have been EQ'd - ie the best bass I've heard in headphones

You know, i wasn't sure i'd call the bass on the 560S "the best", so i decided to mess around a little in REW.
Here's IMD in the bass with the HD560S, somewhere around 100dB. If i had to guess, i'd say that's completely inaudible. I get -41dB or so on the Klippel distortion test (Music J Stone), but i'm pretty sure bass distortion is even harder to hear.

Imagine my surprise when my DCA Closed X only end up a little better! I had really expected the planars to outclass the dynamics substantially.

And then my Moondrop Kato was close at hand so i thought "Surely, these won't do so well." They have tiny dynamic drivers, after all.

Frankly, i'm not even sure how that's possible. I wasn't even going to include the results in this post, but then...

Lesson learned. The HD 560S are really quite impressive headphones. Planar drivers are often talked about for their bass, but they're not substantially better than a well designed dynamic.

 

[IAmAlwaysSerious]

Same here. Mine came with a two notch white felt and a one notch black felt and that black thin foam.

Not sure if there is a different between my two notch white felt and that one notch white felt Dan Clark referred to

Perhaps different DCA headphones come with different sets, though that would be odd. The Closed X came with two sets of white felt, one set of black felt and one set of black foam, like the set on the DCA shop.

 

[markanini]

Yes .. and with an open back planar, if you're lucky, it tolerates EQ to remedy the bass rolloff. That's one of the reasons I like the open-back Sundara -- I could EQ in some sub-bass and it accepted it effortlessly.

And despite my attraction to clean planar bass, the Sundara does have a little bass resonance going on, and I sometimes like it, especially with bass guitar. It strikes me as a good example of our (in particular, my) residual appreciation of at least some bass distortion as euphonic, as Dan Clark avers.

This can technically make a case for Dynamic drivers on open-backs, because their susceptibility to bass resonance can be it's saving grace, when tuned by the manufacturer to make up for the bass roll off. In FR consistency open-backs fare very well with any driver tech, so benefit is lesser from Planar tech in that regard, and it's not a perk when they become even less hard to drive. The remaining perks must end up is rather niche, and situational. But, maybe there's more to Sundara, I don't want to critique a product I haven't tried. Just in general I turn to closed backs because I enjoy the bass more vs. open-backs with EQ. It also brings me closer to the the speaker setup in the control room of a local studio that I had the pleasure to audition.

On a different note, I would like to see more of manufacturer supplied EQ settings, like the Audeze did with their cipher cable. Not in execution but in concept. Because currently I can't audition many well regarded set without finding the bass too lean. An official EQ will rid me of mentally predicting the post EQ sound, which I can't differentiate from actual cope with certainty.

 

[JanesJr1]

I like EQ, but at least on MacOs an IOS, it is very difficult to find a decent system wide solution that is not expensive that will work with everything, for me being Tidal, BluOS, Internet content like Youtube and Netflix, etc. It's a very popular blanket answer here the typical "Just use EQ to get the sound you want" It sounds easy. but in reality, passive headphones should not rely on frequency manipulation to sound good, I will never consider an headphone that don't sound good out of the box on the premiss that it can be fixed afterward, we are not there yet unfortunately. I would also not consider headphone that are that inefficient neither although I had in the past. Flexibility is Key for headphones, along with confort and sound quality. I want them to do all that. My Speaker system can be tweaked, I's not going anywhere, but the beauty of headphones is that It can be used in all sort of situations. I don't want 5 different headphones, I want one. I have to be able to plug it straight in my Laptop and enjoy. Or in my Pro console, or in the headphone output of my Audio Interfa

I'm not sure why you can't plug your preferred headphones into whatever source you need: Hardware-wise, I can do that with just a carefully-chosen dongle and a couple of adapters, even with my current-demanding DCA headphones (and it's even a balanced connection). I haven't used it personally, but if you need portable flexibility with multiple streaming signal sources, I read that the Qdelix 5k dongle does that pretty well, and also makes installing an EQ for particular models of headphone pretty easy if you don't want to have to build an EQ from the ground up. And by using the Qdelix dongle, it means you've got standard endpoint EQ for most possible source devices.

With regard to having to EQ headphones vs. buying a headphone with an acceptable EQ off-the-shelf, I guess most of the world finds buying off-the-shelf good enough. But it raises the question: are you buying headphones as a general electronics consumer (based on a blend of various convenience and interface features), or as an audiophile (based first priority on sound quality)?

I think I agree with you that it is hard to find a headphone that is FR-wise a jack-of-all-trades. But as a result, I find the idea, um, threatening to lose or forego the ability to fine-tune things after the purchase. I mean, I'm kind of amateur on the electronics-side of being an audiophile, but the whole thing of careful listening, and perfecting playback as I get better at the listening, is the REASON I am an audiophile. I think that having to buy headphones based on my preferences for comfort, dynamic range, sensitivity, affordability, etc. AND ALSO with the exact FR curve I need to fit my own HTF and music preferences would be an impossible game of 3D chess that I wouldn't enjoy. It would be lightning-strike-lucky if I it worked. I'm much happier getting something with vaguely Harman-compliant FR curve and EQing it later, as long as the other comfort, interface, SQ and cost features meet my need.

In other words, as primarily an audiophile consumer, the ability to EQ makes things simpler for me, not more complex. And I can adapt as I go along.

 

[Robbo99999]

Nice graphs, those are. Is there any chance you could provide some for the DCA closed X?


You know, i wasn't sure i'd call the bass on the 560S "the best", so i decided to mess around a little in REW.
Here's IMD in the bass with the HD560S, somewhere around 100dB. If i had to guess, i'd say that's completely inaudible. I get -41dB or so on the Klippel distortion test (Music J Stone), but i'm pretty sure bass distortion is even harder to hear.
View attachment 296491

Imagine my surprise when my DCA Closed X only end up a little better! I had really expected the planars to outclass the dynamics substantially.
View attachment 296494

And then my Moondrop Kato was close at hand so i thought "Surely, these won't do so well." They have tiny dynamic drivers, after all.
View attachment 296496
Frankly, i'm not even sure how that's possible. I wasn't even going to include the results in this post, but then...

Lesson learned. The HD 560S are really quite impressive headphones. Planar drivers are often talked about for their bass, but they're not substantially better than a well designed dynamic.

Hi, interesting post, but where are you getting your measurements from? It also seems like an unusual presentation of the distortion results. Could you show the distortion results as a sweep, ie a graph with frequency on the x-axis & distortion on the y-axis (ideally in percentage THD)? Along with letting us know the SPL level at 1kHz for your sweep.

EDIT: or are you purposely making a different point re distortion, as you're using IMD, yet we're used to seeing THD vs frequency?

 

[JanesJr1]

On a different note, I would like to see more of manufacturer supplied EQ settings, like the Audeze did with their cipher cable. Not in execution but in concept. Because currently I can't audition many well regarded set without finding the bass too lean. An official EQ will rid me of mentally predicting the post EQ sound, which I can't differentiate from actual cope with certainty.

It seems like OEM's are instead slowly gravitating unofficially toward Harman EQ, probably because they know the Harman EQ will end up in graphs on a lot of headphone reviews.

 

[IAmAlwaysSerious]

Hi, interesting post, but where are you getting your measurements from? It also seems like an unusual presentation of the distortion results. Could you show the distortion results as a sweep, ie a graph with frequency on the x-axis & distortion on the y-axis (ideally in percentage THD)? Along with letting us know the SPL level at 1kHz for your sweep.

Sorry, those were just super quick tests with a MiniDSP EARS and the default bass IMD tone (41Hz and 89Hz 1:1 at roughly 100dB, not a sweep). I couldn't decide on a single frequency to define bass, so i picked multiple. ]
THD+N obviously means nothing on those because the noise is irrelevant in a transducer.

Frequency sweeps take longer and there's a resonance issue i have to sort out with most headphones above like 2kHz. (not all, vexingly. It seems to me that the straight tube for the ear canal could be modified a little to give much better results, i plan to fix it some day. The rig Amir uses has the same problem for different reasons.)

If you would like better results though, i can probably cook something up.

 

[CedarX]

It seems like OEM's are instead slowly gravitating unofficially toward Harman EQ, probably because they know the Harman EQ will end up in graphs on a lot of headphone reviews.

And probably because OEM’s slowly realize what the Harman target is about: maximizing users preference. In the end more customers will like it, even if some loathe it. I think DCA understands this, and adds a few “Dan Clark touches” here and there.
Audeze is interesting, they appear to target very low distortion, making their headphones EQ-friendly. Providing a set of EQ is a way to communicate what the OEM thinks is right—what they would tune the HP to—but without forcing the user into a “house sound”.

 

[JanesJr1]

And probably because OEM’s slowly realize what the Harman target is about: maximizing users preference. In the end more customers will like it, even if some loathe it. I think DCA understands this, and adds a few “Dan Clark touches” here and there.
Audeze is interesting, they appear to target very low distortion, making their headphones EQ-friendly. Providing a set of EQ is a way to communicate what the OEM thinks is right—what they would tune the HP to—but without forcing the user into a “house sound”.

I'm curious about Audeze ... they may not be forcing consumers into a house sound, but with a funky EQ out-of-the-box, aren't they limiting their audience either to the minority of audiophiles who agree with and practice equalizing; or alternatively to those who really like an off-the-beaten-path EQ curve? (I haven't heard the Audeze phones, but there seem to be relatively common complaints at least on ASR of their out-of-the-box tuning.)

 

[Robbo99999]

Sorry, those were just super quick tests with a MiniDSP EARS and the default bass IMD tone (41Hz and 89Hz 1:1 at roughly 100dB, not a sweep). I couldn't decide on a single frequency to define bass, so i picked multiple. ]
THD+N obviously means nothing on those because the noise is irrelevant in a transducer.

Frequency sweeps take longer and there's a resonance issue i have to sort out with most headphones above like 2kHz. (not all, vexingly. It seems to me that the straight tube for the ear canal could be modified a little to give much better results, i plan to fix it some day. The rig Amir uses has the same problem for different reasons.)

If you would like better results though, i can probably cook something up.

I've got miniDSP EARS too, although I've not experimented with anything IMD related on the measurements, so I'm unfamiliar with that. However, I've viewed countless THD vs frequency graphs of the headphones I've measured on it - I don't have any issues with strange THD results above 2kHz that you mentioned (if I remember rightly). THD thresholds are still likely to be crossed in the bass when I've measured headphones on my miniDSP EARS, as in the highest THD is in the bass, as you'd expect, but with some headphones you do get the occasional spike further up - for instance on a few of my K702 headphones (I have 4 units) there can sometimes be a small THD peak around 2kHz (depending on which of the 4 units I test) which corresponds with Oratory's GRAS measurements of distortion of one of my K702 units I sent him. (So me mentioning 2kHz is not related to your 2kHz you're mentioning - that is literally just for some of my units of K702 that correlates with the GRAS measurement of distortion too - for example on my various HD560s units they don't have a 2kHz distortion peak.).

HD560s measured on my miniDSP EARS is still a low distortion headphone though overall. Although not as low as distortion as Oratory achieved when measuring one of my units on his GRAS, but either way it all generally correlates with what I was saying that HD560s is very good in the bass (Oratory's measurement of one of my HD560s follows):

 

[Dan Clark]

I would really like to see measurements for all 8 different combinations of the included dampening pads (my aeons came with white felt, black felt, and black foam).

Doing A/B comparison is not that easy when it takes a few seconds to swap those inserts.

Same here. Mine came with a two notch white felt and a one notch black felt and that black thin foam.

Not sure if there is a different between my two notch white felt and that one notch white felt Dan Clark referred to

Black means black foam or black felt?

To clarify, here's what ships with the products.

Aeon 2:
2mm Black Foam
Black Felt
2 Notch White Felt (W5)

Aeon RT:
2mm Black Foam
Black Felt
1 Notch White Felt (W10)
2 Notch White Felt (W5)

Sorry about the error, I was in on the weekend and my memory slipped that there is a difference between the RT and A2 kits and I set this up years ago...

Going forward we are going to use the 4 part kit for all Aeon headphones. There was a reason we didn't include the 1 notch white in the A2 but in hindsight I think the 1 notch should be added so it's in all new units as of today. Anyone with an A2 wanting the additional part or who is missing parts can get it from our online kit, it's $19.99 and includes all four parts.

I'm not going to measure all combinations becaues it actually is non-trivial to get exactly reproduced positioning for apple-apple comparison. It's simpler just to explain their function. Here's the effect of the materials, the values are the same for Ether products' analogous parts.

EDIT: In general the reductions are strongest for the peaks and troughs and less in between.

2mm Foam; 4Khz and up -1dB
Black felt; 3Khz and up -1 to -2 db
1 Notch White: 3Khz and up approx -2dB, about -3dB above 7KHz
2 Notch White: 1Khz and up approx -4dB about -5dB above 7KHz

The combinations are easy, foam, black felt and one notch can all be combined.

The 2 notch felt has a pretty strong effect and generally I wouldn't generally combine it with others.

 

[Robbo99999]

2mm Foam; 4Khz up -1dB
Black felt; 3Khz up -1-2 db
1 Notch White: 3Khz up ~-2+dB, about 3dB above 7KHz
2 Notch White: 1Khz up ~4+dB up to -5above 7KHz

I'm just getting confused with reading all the pluses & minuses here, could you re-phrase this to make it less ambiguous. (There's a lot of conflicting + & - signs).