Dan Clark Audio AEON RT Review (closed headphone)

[RHO]

In my experience, getting a good seal has more to do with the shape and size of your head than with wearing glasses. I get a good seal with any type of glasses I wear. But I need headphones with decent clamping force or they will not stay in place when I move my head, even just a little. (I have to set most headphones to the smallest size possible)
Aeon closed RT fits me perfect. No leaking issues even with glasses with wider and thicker arms. (same goes for other headphones)
So in my opinion, wearing glasses or not wearing glasses is less of an issue than the headphones just not fitting your head.

 

[RHO]

Actually testing the bass on these compared to the Hifiman Sundara, both EQed to HTC OE2018 via Oratory1990 PEQ settings.
Very different!!
The Sundara sounds much fuller, warmer.
I do understand that EQing 2 different headphones to the same target does not make them sound the same. (for many different reasons) But the difference here, in the bass alone, is huge.
There's actually a certain quality to the bass on the Aeon RT's that make them sound much leaner. But the bass is actually there.
The longer I listen the better the bass sounds.
@Dan Clark Could it be that temperature has something to do with it? (sitting on a human head makes the temperature increase and also actually playing audio increases temp.)

 

[Rayman30]

I messed with EQ settings to try and get a warmer midrange, I think that's why these sound thin. I honestly don't have an audio background, and with a very basic knowledge of what these settings do... this EQ sounds much fuller to me. Give them a try, some tracks have some midrange shout, but most tracks sound warmer to me now. Also worth noting, these sound much better on my A30 pro than they do my JDS Element ii.

 

[RHO]

I messed with EQ settings to try and get a warmer midrange, I think that's why these sound thin. I honestly don't have an audio background, and with a very basic knowledge of what these settings do... this EQ sounds much fuller to me. Give them a try, some tracks have some midrange shout, but most tracks sound warmer to me now. Also worth noting, these sound much better on my A30 pro than they do my JDS Element ii.

View attachment 191391

Can you show us the resulting curve? (the button with the curved line on, beneath the "effects" button)

 

[Rayman30]

For what it's worth.

 

[RHO]

For what it's worth.

View attachment 191393

You tamed the eargain a little compared to Oratory1990 and you bass shelf is a little different. I can understand why you did that.

 

[Robbo99999]

Actually testing the bass on these compared to the Hifiman Sundara, both EQed to HTC OE2018 via Oratory1990 PEQ settings.
Very different!!
The Sundara sounds much fuller, warmer.
I do understand that EQing 2 different headphones to the same target does not make them sound the same. (for many different reasons) But the difference here, in the bass alone, is huge.
There's actually a certain quality to the bass on the Aeon RT's that make them sound much leaner. But the bass is actually there.
The longer I listen the better the bass sounds.
@Dan Clark Could it be that temperature has something to do with it? (sitting on a human head makes the temperature increase and also actually playing audio increases temp.)

For all my different headphones, I've noticed that bass seems to gain in quantity if I've been wearing a headphone for "a long time" in a listening session vs when I first put them on - I too have thought it could be related to the driver being warmed up my head as well as perhaps the pads conforming more accurately to my head over that listening session thereby getting a better seal. (Or it's a psychological factor, but I seemed to have noticed a difference even if music is not being played the whole time, it's more about the headphone sitting on my head for a minimum of X number of minutes results in the bass being more prominent).

 

[Phoney]

For what it's worth.

View attachment 191393

Yes the best solution for me to get more bass was to lower the higher frequencies by quite a bit. But I felt like it sounded a bit dull after that, even though it made it sound a bit more balanced. Good headphones apart from this issue, so I can see it if someone don't mind the issue too much and still keep them. But personally I ended up trying to sell them.

 

[RHO]

For all my different headphones, I've noticed that bass seems to gain in quantity if I've been wearing a headphone for "a long time" in a listening session vs when I first put them on - I too have thought it could be related to the driver being warmed up my head as well as perhaps the pads conforming more accurately to my head over that listening session thereby getting a better seal. (Or it's a psychological factor, but I seemed to have noticed a difference even if music is not being played the whole time, it's more about the headphone sitting on my head for a minimum of X number of minutes results in the bass being more prominent).

I've only noticed this with the DCAs. Maybe the tension on the membrane decreases a little when temperature increases, lowering the resonance frequency a little. This would influence the tuning on a closed back headphone.

 

[Phoney]

For all my different headphones, I've noticed that bass seems to gain in quantity if I've been wearing a headphone for "a long time" in a listening session vs when I first put them on - I too have thought it could be related to the driver being warmed up my head as well as perhaps the pads conforming more accurately to my head over that listening session thereby getting a better seal. (Or it's a psychological factor, but I seemed to have noticed a difference even if music is not being played the whole time, it's more about the headphone sitting on my head for a minimum of X number of minutes results in the bass being more prominent).

I also feel like sealing felt more tight after having them on my head for a little while. Didn't pay too much attention to how it potensially affected my sound however. My head shape is not really average at all though, I have a fairly large head. This makes it hard to predict comfort and sealing when buying a headphone without trying them first.

 

[Robbo99999]

I've only noticed this with the DCAs. Maybe the tension on the membrane decreases a little when temperature increases, lowering the resonance frequency a little. This would influence the tuning on a closed back headphone.

I also feel like sealing felt more tight after having them on my head for a little while. Didn't pay too much attention to how it potensially affected my sound however. My head shape is not really average at all though, I have a fairly large head. This makes it hard to predict comfort and sealing when buying a headphone without trying them first.

Temperature could be an influence, I think it could be tested by people who have a headphone measuring device, they could do frequency response sweeps shortly after bringing a headphone out of a previously temperature controlled environment. So they'd have their measurement device in their normal room termperature room, and they'd allow the headphone to stabalise or reach a different temperature in a refrigerator - they'd quickly pull it out of the refrigerator and immediately place the headphone on the measurement device and do a quick frequency response measurement. They'd get the headphone to different temperatures (independant of the measuring device, the measuring device stays the same temperature), and plot the frequency responses at the different headphone temperatures. For warmer than room temperature measurements then the tester would wear the headphone on their own head for a period of time, take it off and then quickly measure it on the device - or instead you could put the headphone in a heated cabinet to achieve different warmer than room temperature temperatures. But there should be a way to work out if temperature of a headphone will affect it's frequency response. Afterall, we know that low temperatures can reduce bass in some speakers, you'd think there could well be a similar effect in headphones.

As I said earlier I've noticed changes in all my headphones after wearing them longer on my head during one session, so I'm inclined to think there's something going on here with regards to driver temperature or pad seal changes through the listening session, or just pyschoacoustics of getting used to the bass level as the listening session goes on, but the psychoacoustic point I'm not particularly sold on as I've noticed the effect even when not listening to music the whole time I'm wearing the headphone......it seems like it's important for the headphone to just spend a minimum of X minutes on my head regardless of whether music is playing or not in order to reach optimal bass levels which leads me to think it's temperature or pad seal related.

EDIT: I do want to say that I don't think this explains the major differences/deficiencies in bass you're experiencing with your Aeon RT's.

EDIT #2: in fact, as a simpler way of doing the temperature experiment, you'd just put the headphone in the freezer or something along with a temperature probe that is attached somewhere in the headphone to closely mimic driver temperature. You'd take the headphone out the freezer & place it on your measurement device - do an immediate frequency response measurement, and then you'd keep doing frequency response measurements as the headphone gradually warmed up to room temperature - this way you're taking the exact placement of the headphone variable away from the experiment. Conversely, for the hotter than room temperature measurements you'd do the same thing except you'd get your headphone up to maximum temperature, place it on the measurement device, and then measure it with frequency response sweeps as it gradually cools down to room temperature - so again taking the placement variable out of the equation.

 

[Phoney]

Temperature could be an influence, I think it could be tested by people who have a headphone measuring device, they could do frequency response sweeps shortly after bringing a headphone out of a previously temperature controlled environment. So they'd have their measurement device in their normal room termperature room, and they'd allow the headphone to stabalise or reach a different temperature in a refrigerator - they'd quickly pull it out of the refrigerator and immediately place the headphone on the measurement device and do a quick frequency response measurement. They'd get the headphone to different temperatures (independant of the measuring device, the measuring device stays the same temperature), and plot the frequency responses at the different headphone temperatures. For warmer than room temperature measurements then the tester would wear the headphone on their own head for a period of time, take it off and then quickly measure it on the device - or instead you could put the headphone in a heated cabinet to achieve different warmer than room temperature temperatures. But there should be a way to work out if temperature of a headphone will affect it's frequency response. Afterall, we know that low temperatures can reduce bass in some speakers, you'd think there could well be a similar effect in headphones.

As I said earlier I've noticed changes in all my headphones after wearing them longer on my head during one session, so I'm inclined to think there's something going on here with regards to driver temperature or pad seal changes through the listening session, or just pyschoacoustics of getting used to the bass level as the listening session goes on, but the psychoacoustic point I'm not particularly sold on as I've noticed the effect even when not listening to music the whole time I'm wearing the headphone......it seems like it's important for the headphone to just spend a minimum of X minutes on my head regardless of whether music is playing or not in order to reach optimal bass levels which leads me to think it's temperature or pad seal related.

EDIT: I do want to say that I don't think this explains the major differences/deficiencies in bass you're experiencing with your Aeon RT's.

EDIT #2: in fact, as a simpler way of doing the temperature experiment, you'd just put the headphone in the freezer or something along with a temperature probe that is attached somewhere in the headphone to closely mimic driver temperature. You'd take the headphone out the freezer & place it on your measurement device - do an immediate frequency response measurement, and then you'd keep doing frequency response measurements as the headphone gradually warmed up to room temperature - this way you're taking the exact placement of the headphone variable away from the experiment. Conversely, for the hotter than room temperature measurements you'd do the same thing except you'd get your headphone up to maximum temperature, place it on the measurement device, and then measure it with frequency response sweeps as it gradually cools down to room temperature - so again taking the placement variable out of the equation.

From what I've heard instant temperature changes like that (from cold to warm) can blow up the driver? Because of moisture that can develop in the driver when coming from straight from a very cold environment (like outside) to a warm environment. So might want to be a bit careful with that if that's true.


https://gymhugz.com/blogs/fitness-and-tech-news/can-i-wear-headphones-when-it-s-cold-af-outside
"Condensation Kills Headphones
Water and electronics don't mix. Whilst low temperatures are unlikely to damage headphones, moving them from a colder temperature into a warmer one and then continuing to use them or turning them on too quickly can cause condensation to form inside the headphone – bad news for the drivers."

 

[Daltong]

Hi! Have been using these for a while (with EQ, Qudelix) and recently one of the earpads started disintegrating. For some reason this happens a lot to me with all kinds of headphones (maybe my sweat is super corrosive or something) so being "forewarned by prior experience" I already had spare earpads and proceeded to replace.

After removing the old earpad I took a better look (pic attached)

Do I understand correctly that the white thing with black stripes is raw exposed membrane (seems to roughly match cutaway from website in the technology section but also looks a bit different)?

Should I dread accidentally touching it with a finger as I replace the earpad ? cc @Dan Clark

 

[Phoney]

Did some more digging and found these comments from Sean Olive (Senior Fellow at Harman International) and Dan Clark. Followed by a research report from Todd Welti (Distinguished Engineer at Harman International), and some figures of his results, showcasing how big the differences can be in the bass region with certain headphones due to leakage. Some headphones showing 10-30db differences in measurments at most. Sean Olive talks a lot about leakage effects and acoustical impedance in interviews, as him and Todd has done a lot of research on the subject.

http://seanolive.blogspot.com/2013/04/the-relationship-between-perception-and.html

Relationship between Subjective and Objective Measurements​

Comparing the acoustical measurements of the headphones to their perceived spectral balance confirms that the more preferred headphones generally have a smooth and extended response below 1 kHz that is perceived as an ideal spectral balance (slide 25). The least preferred headphones (HP5 and HP6) have the most uneven measured and perceived frequency responses below 1 kHz, which generated listener comments such as "colored, boomy and muffled." The measured frequency response of HP4 shows a slight bass boost below 200 Hz, yet on average it was perceived as sounding thin; this headphone was one of the models that had bass leakage problems for some listeners due to a poor seal on their ears.

We found that bass leakage related to the quality of fit and seal of the headphone to the listeners' head/ears can be a significant nuisance variable in subjective and objective measurements of headphone sound quality.

https://www.soundstagesolo.com/inde...nad-paul-barton-and-dan-clark-audio-dan-clark

Brent Butterworth: What is your target curve and how did you derive it?

Dan Clark: We try to have a general curve, but one of the interesting things about curves is that there are headphones that don’t sound like they measure. I think it’s because headphones with fundamentally different designs will interact differently with the acoustical impedance of the coupler used to measure them. We’ve tested some headphones as part of our research and development that might measure dead flat up to 4kHz, but they sound like they have a lot more bass than others that have more boosted bass when measured. So you really can’t rely on things like the Harman curve to tell what things sound like.

https://twitter.com/i/web/status/1356696273475178496

"Todd Welti @Harman measured leakage of popular headphones on different test jigs and on humans. As you can see above, the differences are huge (10-30 dB) and vary widely among test jigs, humans and headphones. The errors are largest for closed back and in-ear headphones.
Another factor that affects how accurate these corrective EQ's is the manufacturing tolerances of the headphone. If your sample varies significantly from the test sample(s), all bets are off. So leakage on test jig, leakage on your head, and QC tolerances 3 factors to consider."

https://www.semanticscholar.org/pap...elti/d7eaead9e9e932cc0394b2847c97eea938551712

Headphone leakage effects can have a profound effect on low frequency performance of headphones. A large survey, including over 2000 individual headphone measurements, was undertaken in order to compare leakage effects on test subjects and leakage effects of the same headphones measured on a test fixture. Ten different commercially available headphones were used, each measured on eight different test subjects and a test fixture with several sets of pinnae. Modifications to the pinnae were investigated to see if the leakage effects measured on the test fixture could be made to better match the real word leakage effects measured on human test subjects.

Figure 11 Comparison of the IEC pinnae, IEC Mod1 pinnae, IEC Mod2 pinnae, and plate measurements, averaged left and right ears. Curves were normalized by subtracting out the blocked meatus responses for each headphone.

 

[Rottmannash]

As an aside, I have short hair but it needs a trim (its a growing out grade 4 at the sides) but a big beard. I dont perceive an absence of bass in my RT Open after I up the bass a couple of dB but then I am not a basshead.

Same-I have a beard and the RT Opens and don't have problems w/ seal or bass.

 

[Phoney]

Same-I have a beard and the RT Opens and don't have problems w/ seal or bass.

Definetly seems like it matters more with closed backs (when it matters), but also the shape of the listeners head might matter quite a bit.

 

[RHO]

Hi! Have been using these for a while (with EQ, Qudelix) and recently one of the earpads started disintegrating. For some reason this happens a lot to me with all kinds of headphones (maybe my sweat is super corrosive or something) so being "forewarned by prior experience" I already had spare earpads and proceeded to replace.

After removing the old earpad I took a better look (pic attached)

View attachment 191489

Do I understand correctly that the white thing with black stripes is raw exposed membrane (seems to roughly match cutaway from website in the technology section but also looks a bit different)?

Should I dread accidentally touching it with a finger as I replace the earpad ? cc @Dan Clark

No, this is not the driver membrane. This looks like a thin dust cover to prevent dust or hair "contaminating" the membrane.

edit: fixed typo

 

[MayaTlab]

In my experience, getting a good seal has more to do with the shape and size of your head than with wearing glasses.

I am tempted to think that a pair of headphones that isn't properly designed to fit a wide range of heads is poorly designed .
Most headphones are just poorly designed in my opinion in very non-sensible, occasionally downright stupid ways (lack of resistance-less cup swivel, insufficient range of motion for example, improperly located yoke to cup attachment, etc... the list is endless).

I'll go one further and posit that a pair of headphones that is excessively sensitive to leakage also is poorly designed, particularly in 2022 when we have plenty of reasonable options to reduce that issue.

Could it be that temperature has something to do with it? (sitting on a human head makes the temperature increase and also actually playing audio increases temp.)

What can happen as far as temperature is concerned is that the pads warm up. Some pads' foam will then compress a little bit over a few minutes as it gets increasingly more supple with heat.

Using in-ear mics, I've seen that effect most pronounced on my pairs of Austrian Audio Hi-X65. They have very slim, memory foam pads. When measured after wearing them for a dozen minutes there are small differences vs. cold that roughly correspond to how the FR varies with pad compression. While for me these headphones seal very consistently in all situations, even when the pads are cold, since they behave in a very non-linear way under pad compression, this alters the sound colouration a little bit (so it isn't just a question of leakage).
Conversely on a lot of other headphones I have not measured any difference whatsoever.
No idea how DCA headphones behave in that regard.

Otherwise I would certainly hope that headphones are designed to minimise the effect of humidity / temperature across a sensible range of possible, real-life values. Just like the leakage question above, I'd consider them poorly designed if that isn't the case.
Beyerdynamic seemed to make explicit mention of that issue in their promotional videos for the driver of their more recent DT 900 / 700 Pro X.

Did some more digging and found these comments from Sean Olive (Senior Fellow at Harman International) and Dan Clark. Followed by a research report from Todd Welti (Distinguished Engineer at Harman International), and some figures of his results, showcasing how big the differences can be in the bass region with certain headphones due to leakage.

Rtings has for a long while measured the bass response on five different real humans, and merged it above a few hundred Hz with their ear simulator measurements :

Frequency Response Consistency

Frequency Response Consistency describes the variations in a headphones' frequency response due to their fit on your head.

www.rtings.com

By now this might be the most extensive database of bass response on real humans available ?

I don't think that leakage or sample variation are the only source of individual to individual or ear simulator to individual variations / deviations though .

 

[RHO]

I don't think the bass issues I have are related to leakage in my case. I do hear the sub bass, only the "timbre" is very different compared to the Sundara EQd to the same target.
When I switch off the EQ, the bass actually sounds better, but the mids don't.
When wearing the DCA for longer periods (like >15min or so, I was swapping between Aeon RT and Sundara) the "timbre" got a little better ("warmer"). The Sundara stayed the same.
Because I was swapping headphones all the time I think psycho-acoustics played a smaller role. So I'm still interested if changes in membrane tension due to temperature changes could be a factor.

edit: One funny fact is that I think the bass on the Aeon RTs is great ... when I haven't listened to the Sundara for a long time. Switching from the Aeon RTs to the Sundara the change is not so obvious. Switching back always makes me wonder what happened to that great bass on these DCAs.

 

[MayaTlab]

I don't think the bass issues I have are related to leakage in my case. I do hear the sub bass, only the "timbre" is very different compared to the Sundara EQd to the same target.

Besides the question of sample variation which could play a role in your context, it isn't unheard of that headphones show a number of features at lower frequencies on ear simulators that don't occur to quite the same extent on real humans.
Ex : the ripples you see in the K550 measurements below 200Hz on ear simulators, vs. the rather different results on real humans in that article (even for the ones who got a good seal) : https://www.grasacoustics.com/files...mprovedMeasurementofLeakageEffects_Harman.pdf
Or the "pad bounce" effect here : https://diyaudioheaven.wordpress.com/headphones/earpads/
- which you'll never observe to that extent on Rtings' real humans measurements for the same models.

Because I was swapping headphones all the time I think psycho-acoustics played a smaller role. So I'm still interested if changes in membrane tension due to temperature changes could be a factor.

As a starting point a more likely behaviour, as I suggested, could be related to the pads warming up and the headphones behaving in a non-linear way under pad compression (for reasons I'm not qualified to explain).
Some examples here : https://audiosciencereview.com/foru...er-hd560s-review-headphone.29603/post-1046142
A longer post that illustrates why, in my opinion, evaluating headphones' behaviour under pad compression, and not just breach of seal, can provide quite useful information :

Mark Levinson 5909, new ANC wireless cans that advertise use of the Harman curve

Forgot to give credit to @Sean Olive in his tweet here. I believe this is an actual production sample - it slightly differs how it measures from the production validation sample posted earlier. What @Sean Olive thinks about Brent Butterworth´s measurements at Soundstage Solo...

audiosciencereview.com

I'd love to measure with in-ear mics DCA headphones to be quite honest. They seem quite a bit different from other planars.