Dan Clark Stealth Review (State of the Art Headphone)

[MayaTlab]

So, those are both with some sort of DSP integrated into the headphones?

All active headphones these days have a built-in DSP, or even DSPs, it's about how you use them .
But in the case of the APM's (or Bose 700) ear canal gain region specifically I don't think that the DSP has anything to do with it (or only indirectly as their feedback mechanism locks their response below 800-1kHz regardless of what happens in the front volume, but not above, even though we're still operating under pressure chamber conditions up to a few kHz, so that already makes the ear canal gain region more sensitive to variance in the front volume relative to the feedback range). After a comment from Oratory on Discord I'm also wondering if some of the decisions taken to make them great ANC headphones also makes them more sensitive to what happens in the front volume (related to acoustic impedance but my understanding of that concept is nearly non-existent).

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.

Given the variation in the average loudness of recordings it would quite dumb for Bose to simply look at the internal volume setting and apply the EQ. What I think they might do instead, whenever they have access to the digital format (ie when using bluetooth), is that they look at the volume of the signal vs frequency in real time (-32dB @ 457Hz, -3dB @ 7629Hz, this sort of thing), and apply their volume dependent EQ this way, acting not just as an equal loudness contour adjustment but also a mild compressor. I no longer have my 700 but I've ordered the QC45. One possible way to test this is test them with real time analysis and compare white noise vs pink noise (converted to "white" after the measurement). Or with music as a signal (some analysers allow you to do this). The long term spectrum of most tracks isn't "flat" so a "flat" signal is unlikely to be representative of what the HPs actually output if such an algorithm is in place. Anyway, advanced ANC, active HPs are a b*tch to measure so it's no wonder Oratory stopped providing finalised presets for Bose products.

Also, an illustration (please don't take my own on-head measurements too literally) of what happens when I measure HPs with the same technique after equalisation to Harman using Oratory's presets : https://www.audiosciencereview.com/...snt-like-this-curve.19668/page-22#post-844726
In the case of the headphones involved here I don't think that it necessarily made them sound worse and with a lot of smoothing it can be shown that the presets were mostly successful at bringing them closer together, but it gives you an idea of the sort of potential discrepancies that may remain.

Anyway, this is a bit of a deviation from DCA's new pair of HPs, my apologies.

 

[Zensō]

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.

But I chose not to make a number of other adjustments, all of which would have brought the FR closer to Harman. Making those adjustments toward Harman made the sound quality subjectively worse. Also, adding the bass shelf brought it closer to a number of other targets too, so saying it was somehow specifically related to Harman is not accurate. No offense intended, but it feels as if you’re grasping at straws to make a point.

 

[RHO]

@MayaTlab : I meant to volume match with the HTC when you measure such headphones initially. If the EQ is loudness dependent it would be interesting to know what EQ they apply at the volume Harman did their testing at to get to the target curve.
@acbarn : I'm not offended at all. No worries. You actually answer the questions I have quote well. Not that my personal insights are that important but I do learn stuff from the answers I get here and it makes me understand certain things more.
I know not everybody agrees 100% with the HTC but I got the impression that when they EQ, it was mostly in the direction on the HTC. I got the feeling that the HTC should have a "range". Some deviation up and down from the single line it is represented as now.
But s you say, that bass shelf from your HD800s example could just as well make it match better with the DF.

And now I'll stop derailing the thread.

 

[pozz]

Nonlinear distortion from @amirm's and Jude's measurements:

Unrelated but interesting post on variability: https://www.head-fi.org/threads/som...e-headphone-show.957674/page-13#post-16522120

I find Jude's graphs difficult to read. A lot of white space is reserved for text and logos that don't need to be there. It compresses the otherwise useful data. If I had time I would extract the curves and plot them together, but they seem to roughly agree. The headphone seems to be approaching some limits above 100dB, given how fast the nonlinearity rises.

Compared to my HD820s, which are about 10dB to 20dB better in terms of nonlinearity than most headphones (0.03% or -70dB), the DCA Stealth have won another 10dB (around 0.01% or -80dB).

Amir's review: https://www.audiosciencereview.com/forum/index.php?threads/sennheiser-hd-820-review-headphone.22740/

 

[Dro]

How does 94.3 dB SPL at 1 kHz white noise turn into 80 dB SPL total? That makes as little sense to me as noise floor at -120 dB turning into 150 dB dynamic range.

 

[pozz]

How does 94.3 dB SPL at 1 kHz white noise turn into 80 dB SPL total? That makes as little sense to me as noise floor at -120 dB turning into 150 dB dynamic range.

My take on it is that Jude tries to match the voltage required for white noise with the voltage required for 1kHz at 94dB SPL, which is then used to set voltage level for the frequency sweep. You can't use an equivalent level voltage sweep across different headphones (or across multiple measurements of the same headphone if you are taking it on and off repositioning it each time, like Jude) like you do with speakers since the response is not anechoic. The numbers you'll get are affected by headphone sensitivity, ear coupler gain, fit and seal.

I don't completely understand Jude's intent, but I think the reasoning is that he can check for issues with seal by using white noise. The results we see in the end are averaged as well.

 

[tusing]

Decided to purchase them after all. One of the most beautiful headphones I've seen.

 

[preload]

Decided to purchase them after all. One of the most beautiful headphones I've seen.

It's not a good sign if your post is about how they look and not how they sound.

 

[tusing]

It's not a good sign if your post is about how they look and not how they sound.

I took that picture before I listened to them. Here are some preliminary thoughts:

They sound very clean. I'm not getting any of the slam shortcomings that Resolve and some Head-Fi posters had - these slam plenty well. Then again, I always EQ the sub-bass of all my headphones to where I want (+6 dB here, +4 dB on the Verite C.) I wear glasses, so some of the default bass is bound to leak anyways.

I think they are the best closed backs you can get today. They don't blow me away, but after moving to a speaker setup, no headphones will. I agree with Sean Olive in that headphones will need to develop head tracking and individualized HRTF compensation for proper binaural audio to sound as natural as a speaker setup.

These should be fine for trips and work, though. They are compact, and I love that. They are also very comfortable. For my purposes, they are a step up from the VC in terms of comfort, portability, and tuning. That's good enough for me.

The RME ADI-2 drives them well. I was quite surprised to see that the Qudelix 5K powers them to respectable volumes with plenty clean bass out of the balanced output, even post-EQ. Battery life might be a concern.

I can answer questions but I'm not ready to do a full review just yet. Audio gear takes time to get used to.

 

[BrokenEnglishGuy]

I took that picture before I listened to them. Here are some preliminary thoughts:

They sound very clean. I'm not getting any of the slam shortcomings that Resolve and some Head-Fi posters had - these slam plenty well. Then again, I always EQ the sub-bass of all my headphones to where I want (+6 dB here, +4 dB on the Verite C.) I wear glasses, so some of the default bass is bound to leak anyways.

They don't blow me away, but after moving to a speaker setup, no headphones will. I agree with Sean Olive in that headphones will need to develop head tracking and individualized HRTF compensation for proper binaural audio to sound as natural as a speaker setup.

These should be fine for trips and work, though. They are compact, and I love that. They are also very comfortable. For my purposes, they are a step up from the VC in terms of comfort, portability, and tuning. That's good enough for me.

The RME ADI-2 drives them well. I was quite surprised to see that the Qudelix 5K powers them to respectable volumes with plenty clean bass out of the balanced output, even post-EQ. Battery life might be a concern.

I can answer questions but I'm too lazy to do a full review.

i always think the fact that headphone needs to crack too much the volume for getting tactile bass, and it not about a problem of SPL or roll off... even with flat 20hz you need to crack a lot the volume, in speakers even at low volume you can feel the lower notes

 

[tusing]

i always think the fact that headphone needs to crack too much the volume for getting tactile bass, and it not about a problem of SPL or roll off... even with flat 20hz you need to crack a lot the volume, in speakers even at low volume you can feel the lower notes

Yes, sub-bass is meant to be felt, not just heard, and headphones will never be able to reproduce that. Without an acoustically treated room, most speaker setups will struggle with it too. This is why I'm interested in products like the Subpac X1, which are designed to provide tactile (sub-)bass. It's also why a lot of home theater enthusiasts will install bass shakers, though those are a bit more 'brute force' compared to a Subpac from my understanding.

 

[preload]

I think they are the best closed backs you can get today. They don't blow me away, but after moving to a speaker setup, no headphones will.

They're not the most amazing things you've ever heard? Uh oh.

 

[Robbo99999]

They're not the most amazing things you've ever heard? Uh oh.

Ha, yeah, from the review & the measurements as a whole you'd kinda expect them to be! To me I'd have to listen to them, I'd be super curious if they'd blow me away, I have my doubts, but it's one of the most likely headphones to do so, although I worry about the fact it's a closed back headphone.

 

[pozz]

Ha, yeah, from the review & the measurements as a whole you'd kinda expect them to be! To me I'd have to listen to them, I'd be super curious if they'd blow me away, I have my doubts, but it's one of the most likely headphones to do so, although I worry about the fact it's a closed back headphone.

I don't think they'll blow anyone away. Like all good neutral gear, they are more background than foreground.

 

[Dro]

I am not blown away. But they are enjoyable.

 

[daftcombo]

I am not blown away. But they are enjoyable.

You just described my 80€ AKG K361.

 

[Dro]

K361, K371 and Aeon Closed RT are what I would recommend to anybody looking for a closed headphone on a reasonable budget.

 

[pozz]

Yes, sub-bass is meant to be felt, not just heard, and headphones will never be able to reproduce that. Without an acoustically treated room, most speaker setups will struggle with it too. This is why I'm interested in products like the Subpac X1, which are designed to provide tactile (sub-)bass. It's also why a lot of home theater enthusiasts will install bass shakers, though those are a bit more 'brute force' compared to a Subpac from my understanding.

Hard to say. I've been thinking along the same lines as you and did some research. The most interesting product is the Woojer vest. The transducers apparently work up to 200Hz. But skin/tactile sensation has extremely fast adaptability. Touch something to your arm and, if you're stationary, even while paying attention, the feeling disappears within seconds. Totally different from hearing. I've also not seen conclusive "equal sensation" curves that would tell you what the FR of these transducers should look like. I think just feeding tactile transducers with musical signals is likely to be perceptually incorrect (bass signals by themselves are always muddy; it's the higher frequency components that give them punch or snap) or boring, which is what most people using these devices report. Likely, what's necessary is a DSP buffer which will psychoperceptually translate bass frequencies using the musical signal as source. Might not even be that complicated. Some combo of compression/expansion/gates.

The tactile transducers used in home theatre, some of which are excellent technically, have the same issue. Same goes for the vibration function in controllers. They "enhance", but not precisely enough. Kind of like spatial upmixing, to an extent.

 

[Robbo99999]

I don't think they'll blow anyone away. Like all good neutral gear, they are more background than foreground.

Well, I'm not expecting "colouration", clean well-presented neutral sound can/should blow you away to some extent or at least notice a positive difference.....I've noticed such effects with Anechoic Listening Window EQ on my 308p speakers or unit specific EQ for my K702 that Oratory measured (removal of unit to unit variation as well as removal of driver matching variable).....so good neutral gear can "blow me away" or certainly in terms of enjoying a positive difference. I just have some doubts over how much better this Stealth headphone can be though, that's where my doubts come from, which is why I said I'd be super curious to try the Stealth.

 

[pozz]

Well, I'm not expecting "colouration", clean well-presented neutral sound can/should blow you away to some extent or at least notice a positive difference.....I've noticed such effects with Anechoic Listening Window EQ on my 308p speakers or unit specific EQ for my K702 that Oratory measured (removal of unit to unit variation as well as removal of driver matching variable).....so good neutral gear can "blow me away" or certainly in terms of enjoying a positive difference. I just have some doubts over how much better this Stealth headphone can be though, that's where my doubts come from, which is why I said I'd be super curious to try the Stealth.

Not arguing. Well, sort of. Mostly, I'd like to see these get a lot praise without hype.