This is a review and detailed measurements of the Dan Clark ÆON RT closed back headphone. It was kindly sent to me by the company for testing and costs US $500.
In a sea of similar looking headphones, the ÆON RT manages to distinguish itself with a uniqe shape:
This makes the cup smaller which can be good for travel although I find that it almost touches the top of my ears. Clamp pressure is a tad high for my head causing a bit of strain after a few hours of use.
The pads feel soft and luxurious. A set of filter pads are supplied that get mounted inside to control the level of high frequencies. A white pad with one notch comes installed. I took it out as it attenuates too much of the high frequencies and likely causes some slight comb filtering as well.
The supplied cable is rather soft for this type of cord and comes with nice click on, 4-pin connectors for each side:
The headband is infinitely adjustable and is comprised of very soft leather.
Overall this is a stylish headphone that comes close to being very comfortable for me to wear.
Dan Clark ÆON RT Measurements
The frequency response of AEON RT comes closest to our preference target, especially in low bass, than any headphone I have tested so far:
As you see, the deep bass response almost matches our preference down to 20 Hz. Removal of the white pad causes the right side to exceed our target (without it, it matched it more or less). So what is really left to address is the shortfall in the 2 to 5 kHz. This is where "openness" of sound comes from. Dan says he doesn't think complying with the target generates what he hears live. I agree with him on that, but disagree on desirability of it in the arsenal of the audiophile. I like that energy there!
And indeed, get it with speakers that have flat on axis response in that region. Anyway, we will test this in the equalization section.
Plotting the deviation from our target, this time with both channels showing, shows us the compliance:
If you let your eyes average out the ups and downs some, and ignore the oscillations on the right, you can see that we are pretty close to our target (for a headphone measurement anyway).
But here is the best part about this headphone, distortion level:
Wow! With speakers I celebrate when distortion is below 0.5% at high frequencies at 96 dBSPL. Here, we are below 0.5% across the entire audio band! Even at 104 dBSPL distortion remains highly under control. It is only at 114 dBSPL that it starts to complain a bit but even there, it is better than some other headphones at 94 dBSPL! Remember our recently measured Abyss Diana V2 for example?
Can you even compare the two? Both are planar magnetic technology but the AEON RT is clearly engineered to not distort.
In absolute terms we get this level of THD distortion:
We clear the 40 dB hurdle easily and with substantial margin in 2 to 5 kHz where our hearing is most sensitive.
Group delay graph is quite "sane" indicating we don't have tons of resonating surfaces interacting with each other:
The sharp spikes on the right are due to reflections and frequencies you don't want to touch with EQ. The only thing of note is the dip at 153 Hz which coincides with the same in frequency response.
Impedance is very flat which is good (typical of planar magnetic drivers) but also very low:
You need a very good phone amplifier that does well in my 32 ohm tests. Efficiency is also quite low making this point even more important:
ÆON RT Headphone Listening Tests and Equalization
I originally listened to the AEON RT with the included white pad with one notch in it. I did not find the sound very exciting but also not problematic either. Taking the pad out completely transforms the sound. Yes, it becomes a bit bright so I can see why the pad is included. But due to very low distortion, the slightly elevated highs are not at all annoying. It is just a tonality preference. I rather fix that with EQ than with the pad as I have much more control. So let's dial in a few corrections as we don't need much:
This is the first headphone I have tested which reproduces sub-bass frequencies with no EQ. But you know me: I like a bit more. So I dialed in some. You are welcome to do that or leave it alone. But do note that this increase helps balance a bit of brightness at the other end of the spectrum where I have a shelf to bring down the highs a bit.
The main corrections are the two dips in the frequency response, one at 153 Hz and the other, around 2.8 kHz. The former you could leave out but I found that it helped with male vocals at the level I have it. The other tweak however, opens up the sound and improves spatial (soundstage) quality quite a bit.
With all the corrections, AB tests showed that I could live with no EQ as well but prefer it with EQ. You may lean one way or the other. This is the first time where EQ has not made a super decisive improvement.
With this EQ in place, there is such a delightful accuracy and "correctness" that I fail to describe in words. Usually I am fighting brightness with other headphones created by high distortion, tonality of both. Here, everything is squeaky clean. The sound easily beats some of the best speakers in the world. It is tonally balanced, extends deep, deep into lows like few speakers can ever produce. The high frequency notes delight with brief presence and no exaggeration.
Conclusions
It has taken us a dozen or so headphone reviews to get us a stellar specimen in the form AEON RT. Tonality is almost good enough without any EQ for those of you who don't have access to EQ. With EQ, it rises another class and delights. This accomplishment is more exceptional than it seems because there are so few choices of closed headphones. I sit next to my noisy audio analyzer all day and need to have closed headphone. I finally have one that does justice to my music library.
Was this an accident? Nope. Dan measures his headphones in their development and as such, has been able to find and fix everything I would discover. I was able for example to get frequency response measurements which while were done on slightly different setup, correlated well with mine. He told me distortion would be low, and what they had to do to eliminate measurement errors. Fortunately I was right there with them with optimization of my setup at the outset, so was able to confirm that.
Really, get the tonality right, remove factors that cause distortion and you are there as far as performance. We have seen this in electronics where companies that do their homework during development smell like roses in my reviews and measurements. We seem to have found the first company in that regard when it comes to headphones.
Needless to say, I am very happy to put the Dan Clark ÆON RT closed headphone on my recommended list.
------------
As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
In a sea of similar looking headphones, the ÆON RT manages to distinguish itself with a uniqe shape:
This makes the cup smaller which can be good for travel although I find that it almost touches the top of my ears. Clamp pressure is a tad high for my head causing a bit of strain after a few hours of use.
The pads feel soft and luxurious. A set of filter pads are supplied that get mounted inside to control the level of high frequencies. A white pad with one notch comes installed. I took it out as it attenuates too much of the high frequencies and likely causes some slight comb filtering as well.
The supplied cable is rather soft for this type of cord and comes with nice click on, 4-pin connectors for each side:
The headband is infinitely adjustable and is comprised of very soft leather.
Overall this is a stylish headphone that comes close to being very comfortable for me to wear.
Dan Clark ÆON RT Measurements
The frequency response of AEON RT comes closest to our preference target, especially in low bass, than any headphone I have tested so far:
As you see, the deep bass response almost matches our preference down to 20 Hz. Removal of the white pad causes the right side to exceed our target (without it, it matched it more or less). So what is really left to address is the shortfall in the 2 to 5 kHz. This is where "openness" of sound comes from. Dan says he doesn't think complying with the target generates what he hears live. I agree with him on that, but disagree on desirability of it in the arsenal of the audiophile. I like that energy there!
And indeed, get it with speakers that have flat on axis response in that region. Anyway, we will test this in the equalization section.Plotting the deviation from our target, this time with both channels showing, shows us the compliance:
If you let your eyes average out the ups and downs some, and ignore the oscillations on the right, you can see that we are pretty close to our target (for a headphone measurement anyway).
But here is the best part about this headphone, distortion level:
Wow! With speakers I celebrate when distortion is below 0.5% at high frequencies at 96 dBSPL. Here, we are below 0.5% across the entire audio band! Even at 104 dBSPL distortion remains highly under control. It is only at 114 dBSPL that it starts to complain a bit but even there, it is better than some other headphones at 94 dBSPL! Remember our recently measured Abyss Diana V2 for example?
Can you even compare the two? Both are planar magnetic technology but the AEON RT is clearly engineered to not distort.
In absolute terms we get this level of THD distortion:
We clear the 40 dB hurdle easily and with substantial margin in 2 to 5 kHz where our hearing is most sensitive.
Group delay graph is quite "sane" indicating we don't have tons of resonating surfaces interacting with each other:
The sharp spikes on the right are due to reflections and frequencies you don't want to touch with EQ. The only thing of note is the dip at 153 Hz which coincides with the same in frequency response.
Impedance is very flat which is good (typical of planar magnetic drivers) but also very low:
You need a very good phone amplifier that does well in my 32 ohm tests. Efficiency is also quite low making this point even more important:
ÆON RT Headphone Listening Tests and Equalization
I originally listened to the AEON RT with the included white pad with one notch in it. I did not find the sound very exciting but also not problematic either. Taking the pad out completely transforms the sound. Yes, it becomes a bit bright so I can see why the pad is included. But due to very low distortion, the slightly elevated highs are not at all annoying. It is just a tonality preference. I rather fix that with EQ than with the pad as I have much more control. So let's dial in a few corrections as we don't need much:
This is the first headphone I have tested which reproduces sub-bass frequencies with no EQ. But you know me: I like a bit more.
So I dialed in some. You are welcome to do that or leave it alone. But do note that this increase helps balance a bit of brightness at the other end of the spectrum where I have a shelf to bring down the highs a bit.The main corrections are the two dips in the frequency response, one at 153 Hz and the other, around 2.8 kHz. The former you could leave out but I found that it helped with male vocals at the level I have it. The other tweak however, opens up the sound and improves spatial (soundstage) quality quite a bit.
With all the corrections, AB tests showed that I could live with no EQ as well but prefer it with EQ. You may lean one way or the other. This is the first time where EQ has not made a super decisive improvement.
With this EQ in place, there is such a delightful accuracy and "correctness" that I fail to describe in words. Usually I am fighting brightness with other headphones created by high distortion, tonality of both. Here, everything is squeaky clean. The sound easily beats some of the best speakers in the world. It is tonally balanced, extends deep, deep into lows like few speakers can ever produce. The high frequency notes delight with brief presence and no exaggeration.
Conclusions
It has taken us a dozen or so headphone reviews to get us a stellar specimen in the form AEON RT. Tonality is almost good enough without any EQ for those of you who don't have access to EQ. With EQ, it rises another class and delights. This accomplishment is more exceptional than it seems because there are so few choices of closed headphones. I sit next to my noisy audio analyzer all day and need to have closed headphone. I finally have one that does justice to my music library.
Was this an accident? Nope. Dan measures his headphones in their development and as such, has been able to find and fix everything I would discover. I was able for example to get frequency response measurements which while were done on slightly different setup, correlated well with mine. He told me distortion would be low, and what they had to do to eliminate measurement errors. Fortunately I was right there with them with optimization of my setup at the outset, so was able to confirm that.
Really, get the tonality right, remove factors that cause distortion and you are there as far as performance. We have seen this in electronics where companies that do their homework during development smell like roses in my reviews and measurements. We seem to have found the first company in that regard when it comes to headphones.
Needless to say, I am very happy to put the Dan Clark ÆON RT closed headphone on my recommended list.
------------
As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
