Dan Clark Audio AEON RT Review (closed headphone)

[solderdude]

you couldn't fit the necessary amplification for Dan Clark's Aeon in the cup, you need much more efficient transducers for this task, so probably not the right example?

Indeed, certainly not when you also want the battery to last at least 8 hours... that battery has to fit in there also.
Highend DAC chip, DSP at 96/24 and wifi receiver would also have to be fed.

There is of course the BT Ananda.

Well right now we have been discussing the question of whether EQ is near mandatory for headphone listening. Every review has come with a recommended EQ setting and we discover entire existing databases of EQ settings. Some are recommended only with EQ. Anyone buying into that ecosystem will see the mooted Æon DSP as coming with zero additional cost over any other headphone. You just use the vendor provided EQ settings in exactly the same manner as you use settings for any other HP. The difference only being that the designer of the HP knows that they are freed from any requirement that the HP work without EQ. They don't need to craft in the HRTF, or indeed craft in other tweaks that can be reasonably better managed with EQ.
I would argue that a regime where HPs are designed to work both with and without EQ is simply intrinsically compromised.

There is of course the question of which EQ. Using EQ/DSP based on who's measurements ? When comparing EQ generated by various sources they all differ. It's not that only one of them is correct.. they all are kind-of correct.
Easier to just leave the EQ up to the owner... they can decide which they prefer.

 

[solderdude]

Well right now we have been discussing the question of whether EQ is near mandatory for headphone listening. Every review has come with a recommended EQ setting and we discover entire existing databases of EQ settings. Some are recommended only with EQ. Anyone buying into that ecosystem will see the mooted Æon DSP as coming with zero additional cost over any other headphone. You just use the vendor provided EQ settings in exactly the same manner as you use settings for any other HP. The difference only being that the designer of the HP knows that they are freed from any requirement that the HP work without EQ. They don't need to craft in the HRTF, or indeed craft in other tweaks that can be reasonably better managed with EQ.
I would argue that a regime where HPs are designed to work both with and without EQ is simply intrinsically compromised.

There is of course the question of which EQ. Using EQ/DSP based on who's measurements ? When comparing EQ generated by various sources they all differ. It's not that only one of them is correct.. they all are kind-of correct.
Easier to just leave the EQ up to the owner... they can decide which they prefer.

 

[Rottmannash]

I have one of those finally to test. But from what I know, it should have plenty of power to drive it.

Would the THX 789 drive this to acceptable levels?

 

[amirm]

Would the THX 789 drive this to acceptable levels?

Sure.

 

[Jimbob54]

@Dan Clark I assume I could swap the cable from these with my Ether CX and run them balanced should I have a hankering? Not sure why I would, but just making sure nothing in terms of either physical or electrical connections would prohibit. Good work. Cheers,

 

[Francis Vaughan]

There is of course the question of which EQ. Using EQ/DSP based on who's measurements ? When comparing EQ generated by various sources they all differ. It's not that only one of them is correct.. they all are kind-of correct.
Easier to just leave the EQ up to the owner... they can decide which they prefer.

They are, but the point remains that if the manufacturer can be freed from the need to make the HP in any way flat, and can rely on EQ, it is a different game. Minimally they can provide a recommended EQ. Moreover, there are nuances that it is likely only they will know. The best EQ directly corrects a single physical phenomena with each EQ section. The designer knows what is going on in a manner that someone crafting an EQ with only the end result measurements may find difficult to divine. Something as simple as deciding if two humps are due to two separate issues at different centre frequencies, or two issue, one with a wide skirt, and one of the opposite effect with a narrow skirt. The designer's EQ is very likely much superior. Issues of taste can be left to the tweakers, but I'm not talking about taste. The idea that a designer would take this path, but simply throw the question of EQ out to be solved by the hive mind of the Internet's audio forums is perhaps not what most designer's would imagine doing. Selling a HP with instruction to consult their favourite audio forum to find the needed EQ might not go down well with many customers.

 

[solderdude]

The designer can only look at plots from his measurement device too.
Under the circumstances he measures in with the correction/target curve they have at their disposal on 1 specific or a few specific measuring positions.
When it would be measured per driver tolerances could also be included.
I don't see that happening though, at least not in the coming years.
Maybe some handy Chinese guys might decide to use very cheap and crappy drivers to be 'compensated' and bake it in a cheap BT headphone or ANC device.

 

[PeteL]

Well right now we have been discussing the question of whether EQ is near mandatory for headphone listening. Every review has come with a recommended EQ setting and we discover entire existing databases of EQ settings. Some are recommended only with EQ. Anyone buying into that ecosystem will see the mooted Æon DSP as coming with zero additional cost over any other headphone. You just use the vendor provided EQ settings in exactly the same manner as you use settings for any other HP. The difference only being that the designer of the HP knows that they are freed from any requirement that the HP work without EQ. They don't need to craft in the HRTF, or indeed craft in other tweaks that can be reasonably better managed with EQ. Then they can start to add elements to the design that migh improve the overall quality that woud normally not be possible becuse they would affect the frequency response badly. It is all win.
I would argue that a regime where HPs are designed to work both with and without EQ is simply intrinsically compromised.

Make sense, It is tough a small market if the DSP is not baked in. By nature, even less efficients headphones like this, are portable or at least carriable, yes you have your rig at home with decent amplification but me personally, you want the flexibility to bring it on a trip, listen to different players, different amps, different source devices, I feel most would not agree that it's ok to be mandatory to dial in a EQ curves for the headphones to be listenable in different settings. But I can't and I don't speak for everybody. Now isn't this a similar approach of what Bose and Kef was doing for their speakers in the 80s? coming with a processor to be inserted in the chain, specific to their own design to correct the Frequency response and focus on different parameters. It didn't really stood the test of time for consumer audio, where in pro audio it's all over, You don't set up a PA system without EQ, obviously, but I believe that the rise of Room correction in listening rooms being more understood now, we will more and more accept that EQ is just part of the chain and your approach may come back, especially with home speakers which to me makes a bit more sense. If we do correct for the room, why not correct for the speaker themselves.

 

[Jimbob54]

Just out of interest @amirm , did they send you the RT open too? Was looking on the site and see both available. HAving the Ether CX, I am minded not to double down on DCA closed planars but the RT open might make a nice birthday self present.

 

[randomusername]

When the desktop is playing just as loud as the 9038D do both sound closely the same ?

I don't have any measurement device other than my ears, but i do my best matching volume on the sine wave. Sounds pretty loud for me tho, may be Ivan's specs on the conservative side and the pop music I choose for comparison (with punchy bass lines) don't have much dynamic range. I am not sure about 18db peaks you have accounted for. Btw how you got 86mA Current limit? is this approximation or you are referring to some measurements? does it mean more likely to hit current limit when closer to max volume?
I understand that human ears are bad at measurements and psychoacoustical factors come into play, but the difference seems to be pretty obvious for me. Also there is many people who are referring to that anemic sound and lacks of dynamics without powerfull amp.

 

[Dan Clark]

$500, great measurements, thank you @amirm . I sense there is a very high productivity in headphone measurements. No heavy boxes to move around and the measurement itself probably takes a lot less time than the Klippel. Lower shipping costs also are a big help.

Size was one reason we make headphones not speakers, though for fun we built a big synergy horn with bass bins that go to 20 Hz for festivals...

Something that has been in the back of my mind for some time, especially with respect to headphones (but also with speakers) is the idea of a design that simply avoid the various design tweaks needed to shape frequency response, and relies purely on active correction. So I wonder of @Dan Clark might be just the right person to ask. This strikes to the question of open backed versus closed.

Clearly open backed are advantaged by essentially radiating the back of the driver out into a near infinite void. With the energy never to return. A closed back design needs to manage stored energy in its multifarious forms. But both designs also have sculpted frequency responses designed to mimic the wearer's HRTF and manage interaction with the pinna. This means some interesting tweaks and frobbing with the mechanical and acoustic properties of the design in ways that might not be the best answer for best possible performance. One wonders if a closed back headphone that was designed with as perfect damping in the rear cup as possible could be made and its frequency response shaped with a bespoke set of equalisation parameters. Within the constraints of the size of the cup one might be able to achieve the best of both worlds. No stored energy issues, really good bass, really good isolation.
It seems that the market is not quite ready for such a product, but is very very close to the point where it might be. Most of the ducks are lined up. So maybe. Perhaps Dan could make an Æon DSP and test the waters. I would by one.

DSP doesn’t really address stored energy and there is no solution I know if to totally eliminate stored energy. Plus many devices and most people have no idea how to use PEQ so you’d then rely on integrated electronics with presets for mass use, amd that restricts electronics choice. I’d rather get the design optimized and let those who wish fine tune it...

 

[Dan Clark]

@Dan Clark I assume I could swap the cable from these with my Ether CX and run them balanced should I have a hankering? Not sure why I would, but just making sure nothing in terms of either physical or electrical connections would prohibit. Good work. Cheers,

All our planar headphones use the same cable so sure.

 

[Frank Dernie]

Maybe some handy Chinese guys might decide to use very cheap and crappy drivers to be 'compensated' and bake it in a cheap BT headphone or ANC device.

Back in the early 70s I worked in the R&D department of a gear manufacturing company.
One thing made there were super accurate rack and pinion gears to be fitted to the traverses of machine tools to measure the precise position of the work relative to the cutter. They were very, very, expensive to make and to measure in inspection.
One very bright colleague of mine came up with the idea of using the inspection data of the accuracy of a commercial accuracy rack and pinion to create an error table and use that in a microprocessor device to correct its output to be as precise as the super accurate ones.
We were in the early days of our use of microprocessors and that is the first really accurate and useful one I know of.
My first experience of using "equalisation" to correct errors Results were just as good, eventually better, but the manufactured part was much cheaper.

 

[solderdude]

I don't have any measurement device other than my ears, but i do my best matching volume on the sine wave. Sounds pretty loud for me tho, may be Ivan's specs on the conservative side and the pop music I choose for comparison (with punchy bass lines) don't have much dynamic range. I am not sure about 18db peaks you have accounted for. Btw how you got 86mA Current limit? is this approximation or you are referring to some measurements? does it mean more likely to hit current limit when closer to max volume?
I understand that human ears are bad at measurements and psychoacoustical factors come into play, but the difference seems to be pretty obvious for me. Also there is many people who are referring to that anemic sound and lacks of dynamics without powerfull amp.

Lack of dynamics is something an amp does not have. Anemic sound means it either has audible and very measurable roll-off.
Another reason is it doesn't play loud enough.
When at the same 'low impedance' they still sound different then it must be roll-off.
The 9038D may have output capacitors or it has an internal DCDC converter that may be current limited. You can ask @IVX ?

Going from this data:
200mW@40 Ohm@1kHz@THD=1% = 2.8V = 70mA
180mW@32 Ohm@1kHz@THD=1% = 2.4V = 75mA
120mW@16 Ohm@1kHz@THD=1% = 1.38V = 85mA
This means the voltage drops because there is current limiting. As the output voltage is nearly halved it is easy to deduct the current limit is reached.
Maybe it is a fraction higher say 90mA.
90mA x 13 = 1.17V maybe slightly lower.

The peak/average ratio may well be lower than 18dB, it could well be 6dB with low DR recordings.

In any case... An amplifier that doesn't sound dynamic lacks output power. When it sounds anemic it either does not have enough power or is rolled off.
The AEON is a relative insensitive headphone. To make it shine connect it to an amp that can properly drive it.
A single ended USB dongle or phone is not enough.
Connect the 9038D to an amp and it will sound excellent.

 

[bloodevil]

Newby question: What adaptor do I need to connect the 1/4 2m VIVO stock cable (I suppose this is balanced but if it isn't please tell me) to my FiiO Q3 balanced output (2.5 or 4.4)? I can't seem to find any adaptor and wouldn't spend 200 (two hundred wtf) $ for the 4.4 one from the official site.

 

[antdroid]

@amirm are you concerned about the L/R channel imbalance? The left and right sides vary from +3dB to -3dB to +3dB across the range. It almost looks like they could be different headphones.

 

[BrokenEnglishGuy]

Nice to se the aeon flow ( aeon rt ) is well measure, the ether flow it's the same but with bigger driver

 

[PeteL]

@amirm are you concerned about the L/R channel imbalance? The left and right sides vary from +3dB to -3dB to +3dB across the range. It almost looks like they could be different headphones.

It’s not fully clearly explained but it seams to suggest that one side are with the supplied filter pad? I’m a bit confused by this too

 

[ayane]

Really curious to see how the Aeon 2 measures, either open, Noire, or closed. I've got the original AFC and I'm happy with them, but I want to switch to something more open-sounding.

 

[amirm]

@amirm are you concerned about the L/R channel imbalance? The left and right sides vary from +3dB to -3dB to +3dB across the range. It almost looks like they could be different headphones.

I am not. I have been wearing these for months and the pads have worn differently. And at any rate, we need to ignore differences of this nature.