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Dan Clark Stealth Review (State of the Art Headphone)

Robbo99999

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So while Harman's research tends to give credence that once FR is a controlled variable, provided distortion is low enough, HPs are similarly rated, I'm not certain that FR remains a sufficiently well controlled variable in terms of actual on-head response that it makes questions of "cup reflections and design" not that important.
Just to quote your conclusion part of your post, I agree with that and it fits my experience EQ'ing headphones to the same curve from measurements, so I agree with your post that was tempering some elements of what @tusing was concluding in his post. We can't use frequency response to totally equate the quality of two headphones - eg comparing DCA Stealth to another headphone that can mimic that frequency response. That's where the importance of the subjective review comes in or indeed listening to the headphones yourself. Harman is an excellent step forward, but it's not a done deal for the reasons you mentioned (HPTF variability, HRTF variability & additionally some inherent user measurement inaccuracies that can be associated with chosen measurement methodology (& implementation) to arrive at the final EQ'able measurement e.g. do you use an average of a number of measurements from different headphone reseatings or do you choose just one actual measurement to EQ, etc, and then a last additional point you have unit to unit manufacturing variance as well as pad wear that will alter the frequency response away from any measurement you find on the internet).

Fantastic interview with Sean Olive, posted by Audioholics today, describing the methodologies and justifications behind the design of the Harman target. Sean Olive mentions the DCA Stealth and @amirm 's review at 51:20, but it's really just in passing. I'd recommend that people watch the whole video, it's very educational!

One interesting aspect I found is that the Harman target was preferred regardless of cultural background or musical/listening experience - even very experienced listeners almost universally preferred the Harman target.

Another interesting aspect was that experienced listeners were almost completely unable to differentiate between Headphone A equalized to sound like Headphone B, versus just Headphone B (with the rare exception of when either headphone might exhibit a significant amount of distortion.) This implies that cup reflections and design really might not play as big of a role as we like to think, and audiophiles might not be as good at distinguishing non-FR aspects as they like to think.

Sean Olive makes it very clear that you don't need to spend $4K to get a headphone that performs extremely well. A lot of the headphones in the $50-$200 range match the Harman target closely. I'd love to see Amir review some of the headphones in blue:

View attachment 153837

It's funny to imagine this graph extending all the way to $4000, running well off of my screen, and a single dot slightly higher than the JBL Tune 710 representing the DCA Stealth. (Didn't stop me from purchasing the Stealth, though!)

The future of headphones will probably be cheap drivers DSP'd to the Harman target, with some degree of head tracking with binaural reproduction, and audiophiles will be at a loss as to what to spend their money on next.

Like a mechanical watch versus a quartz watch, headphones like the Stealth are very much a novelty for the rich, in that what makes them unique is that they don't need DSP to achieve a high preference rating, but that is immaterial to the sound quality in the end. If Olive is right, you should be able to get Stealth levels of performance for a fourtieth of the price.
 
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MayaTlab

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Just to quote your conclusion part of your post, I agree with that and it fits my experience EQ'ing headphones to the same curve from measurements, so I agree with your post that was tempering some elements of what @tusing was concluding in his post. We can't use frequency response to totally equate the quality of two headphones - eg comparing DCA Stealth to another headphone that can mimic that frequency response. That's where the importance of the subjective review comes in or indeed listening to the headphones yourself. Harman is an excellent step forward, but it's not a done deal for the reasons you mentioned.

Yes and I'll add to that that two headphones that score similarly doesn't necessarily mean that they no longer have any discernable differences. The latter is a sufficient condition for them to score the same, but not a necessary one. Harman's articles unless I'm mistaken, so far, focus on rating headphones on a scale, not on AB/ABX tests or something of that kind.
But at least, if the recording approach is used, which I believe is the only way to truly control the FR variable, then there is quite a bit of evidence that two headphones with the same FR and low enough distortion will score similarly.
I'd love to see a cheaper, more practical (particularly for measuring headphones) and technologically current version of that stuck in more people's ears, and learn about the results : https://www.etymotic.com/product/er-7c/
 

Robbo99999

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Yes and I'll add to that that two headphones that score similarly doesn't necessarily mean that they no longer have any discernable differences. The latter is a sufficient condition for them to score the same, but not a necessary one. Harman's articles unless I'm mistaken, so far, focus on rating headphones on a scale, not on AB/ABX tests or something of that kind.
But at least, if the recording approach is used, which I believe is the only way to truly control the FR variable, then there is quite a bit of evidence that two headphones with the same FR and low enough distortion will score similarly.
I'd love to see a cheaper, more practical (particularly for measuring headphones) and technologically current version of that stuck in more people's ears, and learn about the results : https://www.etymotic.com/product/er-7c/
Yep the calculated Preference Rating that can be calculated from the frequency response is not fine-tuned enough to assume that 2 identically scoring or close scoring headphones will sound the same - two headphones can have different frequency responses and still score the same I believe, so it doesn't fully describe the frequency response as a start. Oratory himself says that you can't use the calculated Preference Rating to compare headphones, I think he said once that essentially you want to make sure you EQ'd headphone is in the 90's or above, it's not like you can say a 90 headphone is worse than a 95 headphone or something. I really don't pay attention to the calculated Preference Rating of a headphone, I just look at the frequency response (and any distortion measurements) to conclude what I think to a headphone in terms of it's objective measurement quality, then I'd look at subjective reviews to get an additional picture (particularly on soundstage and fitment / manufacturing quality issues). Preference Rating Number doesn't interest me in headphones and not much in speakers either.
 
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pozz

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I just listened to the DCA Stealth at a local dealer's. I was the first one to ask about it, apparently. They took a new pair out of the box for me to try. First and lasting impression was that these are flawless. I could definitely mix on them and wished I could have taken them home for a proper session.
 

tusing

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Anyone else think DCA Stealth + Subpac X1 would be an incredible combo? It would easily solve all concerns with slam and impact, while maintaining the incredible FR of the Stealth. Basically endgame closed-back setup.
 
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amirm

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At least for Harman, the above graphic tells the story: for them the target is primarily about marketing and sales.
Didn't you watch the part that Sean said getting internal groups to follow their targets took too long? That other companies started to adopt it before they did?

The work they do is much closer to pure research than R&D. They have to work to sell the ideas internally and as such, are not motivated directly by product group wants and desires.
 
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amirm

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Anyone else think DCA Stealth + Subpac X1 would be an incredible combo? It would easily solve all concerns with slam and impact, while maintaining the incredible FR of the Stealth. Basically endgame closed-back setup.
There is no issue with "slam and impact" to be solved. And even they were, a tactile one would be too distorted to be my choice.

I continue to be so impressed by the deep bass with the Stealth. It just puts a smile on my face when I hear notes that even some of the best speaker systems can't produce or do so this cleanly.
 

frix

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I'd like to know what 4th generation driver means? So there have been changes made to the driver other than the meta material?
 

Zensō

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Didn't you watch the part that Sean said getting internal groups to follow their targets took too long? That other companies started to adopt it before they did?

The work they do is much closer to pure research than R&D. They have to work to sell the ideas internally and as such, are not motivated directly by product group wants and desires.

78DA64A9-386B-46D1-BF64-8DF2308E2847.jpeg

Understood. My point is that Harman marketing appears to be using adherence to the target (predicted preference rating) as the sole determinant of “better sound“ in their materials. In other words, better adherence to target = better sound. This is clearly not always the case, but it does make a good sound bite for marketing purposes
 

RHO

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This is clearly not always the case,
Do you have examples where less adherence to the target resulted in better sound. That would mean that when you would apply EQ so the headphones would adhere better to the target they would sound worse.
 

Jimbob54

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Do you have examples where less adherence to the target resulted in better sound. That would mean that when you would apply EQ so the headphones would adhere better to the target they would sound worse.
I can easily foresee cases where bumping the low end to Harman levels might increase distortion to audible levels at some higher listening levels. Theoretically of course. I might experiment with my beyer t1
 

Zensō

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Do you have examples where less adherence to the target resulted in better sound. That would mean that when you would apply EQ so the headphones would adhere better to the target they would sound worse.
Anecdotally and subjectively I have a number of examples, but of course preference without blind testing is not a valid argument here, so I won’t go there. There are objective examples where the Harman bass boost causes distortion that may be audible, including some of the reviews here.
 

Zensō

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I can easily foresee cases where bumping the low end to Harman levels might increase distortion to audible levels at some higher listening levels. Theoretically of course. I might experiment with my beyer t1
There is also masking that can happen, which in my purely subjective experience can cause reduction in perceived soundstage.
 

RHO

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I can easily foresee cases where bumping the low end to Harman levels might increase distortion to audible levels at some higher listening levels. Theoretically of course. I might experiment with my beyer t1
That still doesn't mean that when they would adhere more to the Harman curve initially, before EQ, they would have sounded worse.
Yes, if THD rises to unacceptable levels after EQ, they could sound worse than without EQ. But that just means they can't handle bass boost. Not that would have sounded worse when adhering more to the Harman target.
 

Jimbob54

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That still doesn't mean that when they would adhere more to the Harman curve initially, before EQ, they would have sounded worse.
Yes, if THD rises to unacceptable levels after EQ, they could sound worse than without EQ. But that just means they can't handle bass boost. Not that would have sounded worse when adhering more to the Harman target.

Misunderstood your post. Big caveat is that the listener in question has to prefer Harman to a target curve thats different. But logically, to someone who fits the Harman liking category, then one would have thought a HP that is closer to it would "sound better" than one further away from it.

"Sounds better" is clearly one of the foundations of the Harman work, but even they dont claim it "sounds better" for everyone.
 

RHO

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Misunderstood your post. Big caveat is that the listener in question has to prefer Harman to a target curve thats different. But logically, to someone who fits the Harman liking category, then one would have thought a HP that is closer to it would "sound better" than one further away from it.

"Sounds better" is clearly one of the foundations of the Harman work, but even they dont claim it "sounds better" for everyone.
I find it quite interesting that when you read subjective reviews and the reviewer adds EQ settings to the review, the result mostly brings the headphones closer to the HTC. I've yet to see one that EQ's them further away from the target.
If there are examples, I would like to see them. Could be interesting to find out why they suggest the EQ settings for those headphones.
 

MayaTlab

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Do you have examples where less adherence to the target resulted in better sound. That would mean that when you would apply EQ so the headphones would adhere better to the target they would sound worse.

A typical example for me is the AirPods Max. Applying EQ presets to supposedly bring it closer to Harman, particularly the ones based on the measurements that show the most deficient ear canal gain region, make them invariably sound worse, because all the samples I’ve measured so far on my own head have a fairly decent response in that region to begin with - or at least nowhere near as deficient (if you consider the HD560S, HD650 and K371 decent proxies to represent the target, as my own on head measurements are only somewhat valid for relative comparisons) : https://www.audiosciencereview.com/...cancelling-headphone.25609/page-2#post-872884

It’s even worse for the Bose 700 BTW if I use Oratory’s preset, but for this one I don’t trust my own on head measurements (nor most online measurements that don’t take into account its volume dependent EQ for a start).

It’s probably less because they adhere less to Harman’s target intent but rather because of a discrepancy between the test rigs and the way they behave on my head.
 

Zensō

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I find it quite interesting that when you read subjective reviews and the reviewer adds EQ settings to the review, the result mostly brings the headphones closer to the HTC. I've yet to see one that EQ's them further away from the target.
If there are examples, I would like to see them. Could be interesting to find out why they suggest the EQ settings for those headphones.
OK, I’ll bite. This is 100% subjective, but one example is Oratory1990’s Harman EQ curves for the HD800S. Whether it’s the 2018 Harman or the modified “Harman HiFi”, for me they cause the soundstage to noticeably collapse and reduce instrument separation and clarity, reducing some of the best qualities of this headphone. I get better results with a simple +4 100 Hz shelf which leaves the rest of the FR untouched. This leaves the unique spatial qualities of this headphone intact while adding a bit of warmth and bass extension to balance out the FR. This is only true for me, on my head, with my ears, and may not hold true for anyone else. That, in my opinion, is the problem with using any one particular target as the end all, be all.
 
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RHO

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A typical example for me is the AirPods Max. Applying EQ presets to supposedly bring it closer to Harman, particularly the ones based on the measurements that show the most deficient ear canal gain region, make them invariably sound worse, because all the samples I’ve measured so far on my own head have a fairly decent response in that region to begin with - or at least nowhere near as deficient (if you consider the HD560S, HD650 and K371 decent proxies to represent the target, as my own on head measurements are only somewhat valid for relative comparisons) : https://www.audiosciencereview.com/...cancelling-headphone.25609/page-2#post-872884

It’s even worse for the Bose 700 BTW if I use Oratory’s preset, but for this one I don’t trust my own on head measurements (nor most online measurements that don’t take into account its volume dependent EQ for a start).

It’s probably less because they adhere less to Harman’s target intent but rather because of a discrepancy between the test rigs and the way they behave on my head.
So, those are both with some sort of DSP integrated into the headphones?
With the volume dependant FR models you should volume match with the HTC. Test were done at a fixed SPL level if I'm not mistaken.
 

RHO

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OK, I’ll bite. This is 100% subjective, but one example is Oratory1990’s Harman EQ curves for the HD800S. Whether it’s the 2018 Harman or the modified “Harman HiFi”, for me they cause the soundstage to noticeably collapse and reduce instrument separation and clarity, reducing some of the best qualities of this headphone. I get better results with a simple +4 100 Hz shelf which leaves the rest of the FR untouched. This leaves the unique spatial qualities of this headphone intact while adding a bit of warmth and bass extension to balance out the FR. This is only true for me, on my head, with my ears, and may not hold true for anyone else. That, in my opinion, is the problem with using any one particular target as the end all, be all.
But the bass shelf still gets it closer to the HTC then stock.
What I'm getting at is that almost everyone likes to hear something that is at least something approaching the HTC to a quite narrow margin. Maybe a little less bass, maybe a little more treble,...
But when something sounds off, corrections are almost always done in the direction of the HTC.
In you example, you gave the HD800s a bass shelf. Bringing it closer to the HTC. Measurements show it is a little lacking in that regard without EQ, if you compare it to the HTC.
 
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