[jude]

This may already have been answered, but have you measured early production serial number HD 800 S as well? Just wondering as silent product revisions could in theory also explain these changes (HD 650 had a clear revision done at one point and T1 went through some early changes too).

Yes, the first Sennheiser HD 800S we measured was S/N 00205. The second one we measured was S/N 13134.

As I've mentioned before (especially in this post), it seems it's not the Sennheiser HD800S as much as the Sennheiser HD800 measurement in the original InnerFidelity FFT from where this conclusion came. This is why I'm more interested in measuring HD800's. We still haven't come across one yet (all of the ones we've tested are stock, unmodified) that has higher H3 than H2 as shown in InnerFidelity's FFT. That measurement led to a theory that has become the rather definitive explanation of the HD800S's sound, but perhaps not accurately so.

As much as I like reading threads like this, wouldn't it have been far easier to simply ask Sennheiser if they add in 2nd order harmonics to the HD 800S?

We did ask, and posted as much. Our measurements are consistent with Sennheiser's feedback. I'm surprised this wasn't asked far sooner.

The size of the difference, and their denying adding it intentionally has me leaning towards the S version having more bass, and other minor changes, adding "something" beyond more bass, as a side effect. It was heard as 2nd harmonic distortion, which it was to a very small degree. He said they added it, but not "intentionally" added it. If a change they made added it, they did, just not intentionally.

Just to clarify, that's not what I said. At this point (but there are still a few brand new HD800's that just arrived to measure), I think the HD800S is simply a different tuning. The belief by some that more perceived bass can only be explained by higher H2 (which started with that original FFT that showed a 20 dB difference) might suggest that any headphone with more perceived bass should have significantly higher measured H2 than the original HD800. That's not the case.

As has been said before, this is an opportunity for (further) inquiry and not hastily reaching conclusions...

I'm definitely trying to avoid that.

...I'd also be curious about the output impedance of the headphone amps used for measurements on both systems, as this may well have an effect on THD readings.

The output impedance of the Audio Precision APx1701 is ≈0.13 Ω.

This is all so ****ing silly lol

I don't think so. I did a quick search, and what follows is just a sampling of what I found (and there's a lot more).

From reddit:

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...The HD800S has a harmonic distortion in the bass to add a bit of warmth. The SDR mod does the same changes except for the harmonic distortion.

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The HD800S has higher second order harmonic distortion than the regular HD800 as per Tylls measurements. More to come.

2nd order distortion only in the bass would be quite hard to hear.
Though it could be a magnet asymmetry quality problem.

Not really. It's quite easily perceived as a muddier, more bloomy quality in the bass.

---

The 800S also boosts the bass energy, by adding a smidge of second harmonic distortion to the bass frequencies...

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...HD800S is basically an HD800SDR with ****ed up bass...

Why do you say ****ed up? The bass sounds really nice to my ears.

In comparison to an HD800 they did something wonky to it

The "wonky" thing they did was to increase the second harmonic distortion in the lower frequencies. This increases the amount of energy in the bass - and hence the perception that there's more of it - without sounding "wrong", as it's at a harmonic. But this does also make the bass a bit less precise, if you're really paying attention.

Does it sound unnatural or what?
Also, I see you have an eikon... what is your opinion on the difference between HD800 SDR and it?

I don't have my Eikon yet, sadly, supposed to get it just after Canjam (hopefully), but by all accounts it's much more musical and forgiving.
HD800S has more bass but somethings off about it.

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I briefly tried the Sonarworks EQ, but wasn't very impressed: the low end felt unnaturally bloomy and sound stage seemed to collapse from whatever was happening to the high end. I suspect 1) low end harmonic distortion was becoming quite audible, and 2) the headphone's frequency response in the mids and highs contributes to its airy spatialness. Plus I could only get the thing to work in Foobar as the systemwide program didn't like my DAC.

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Don't be afraid of EQ is what I say. But since you bought the S, you can't do much about bass level since they added lots of harmonic distortion to that region...

Heh. Few if any of the initial impressions mentioned it on Headfi or SBAF. Once Tyll mentioned, suddenly everyone hears it like night and day. Had to find it in my history but this comment was hilarious to me...

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On TheVerge:

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...Did you see that the way they increased bass for the S model was to introduce some minor distortion?

I’m sure these sound incredible, but there’s something about that that gives me pause. You go to the HD800 for perfection; it seems like adding distortion for more money is just the wrong way to go...

I watched Tyll Hertsens’ video review of them as well, but I honestly don’t hear the distortion of which he speaks. Ultimately, as I argue in my review, the 800 S feels like a more human-friendly set of headphones.

What use is a perfect-response headphone if it doesn’t sound pleasing to people (who are fallible and flawed and have funnily-shaped ears)? Maybe I’d put one of those on a stethoscope or some other tool that requires absolute aural precision. But the HD 800 S have no purpose other than pleasure listening. People don’t typically mix music with open-back headphones.

It’d be good to hear from anyone that believes (s)he can hear an audible degradation in quality between HD 800 models, but I have zero complaints about the clarity of the S.

---

A search just in this thread yielded the following (and, again, there's a lot more):

Slight increase in bass distortion as compared to the original which gives the S more percieved bass and fuller sound. So just because the original measures better doesn't mean it sounds better. Tyll described the resulting effect of introducing bass distortion as Senneheiser having a trick up their sleeve.

There were dissenting views from the get go, they were simply drowned out by the "TEH BASS IS BETTAR" and the "HD800S is an upgrade" crowd. Sorrodje's measurements actually shows significantly higher bass distortion compared to the original. At most, this headphone is side-grade. For me its neutered HD800 and a downgrade in all the aspects of sound I care about.

The bass is very similar to the original HD 800, it's just a little bit stronger. If the measurements showed it was due to more bass rather than %TDH, I would have believed it.

this is about on 'specially tuned' bass part here...
from some other thread 'out there'
[...}looks like S distortion matches the HD650 pretty well, at least based on IF measurements.[...]
[...]this is mostly 2d order distortion in the bass-zone[...]

with the MASSIVE caveat of added second order harmonic distortion and muddied bass

Yep, OK, I'm guilty of not reading closely enough as well - my bad!

I'm still not sure that conclusion can be drawn that the original 800 is 'better' though. It's not like the introduction of second-order harmonic distortion was a mistake on Sennheiser's part, but rather the 'trick' Tyll referred to - a legitimate approach to giving a slightly warmer signature, despite measuring worse. Isn't it effectively just a different presentation? For those of us not interested in modding their headphones, like myself, then the S is arguably a better choice. The other take away for me is that this kind of bass distortion is unlikely to be audible unless EQ'd up, hence why the original 800 is more amenable to EQ.

I actually honestly think that nobody at Sennheiser thought that the original HD800 had such a big problem either. The HD800 was years in R&D and when they finally released it, it was the best dynamic headphone that they could produce. I simply don't think that they would have let it out of the door if they thought that most people would find the raised response at 6kHz (which they surely knew about) to be a problem.

IMHO the HD800S is simply an answer to/for those people who do. They've just given those people what they wanted - a smoother treble and an increased bass presence (albeit at the expense of increased distortion). Notice that the original HD800 is still available, and also that it took them a long time to get around to doing anything about the 'problem'.

Personally, I'm going to wait for the HD1000!

...I think the thing with the bass is that it is audible as a distortion (if you know what to listen for) but it doesn't become a problem unless you try to EQ it up too much. And yes, it is a 'trick'. There actually isn't any more bass, but the increased second-order harmonic distortion makes it sound as though there is. It's still a relatively undistorted bass for a headphone though.

Best to describe it is lack of sub bass. The HD 800 S fills in more sub bass which the HD 800 misses (mimicked by adding 2nd harmonic distortion apparently).

Why should I read what someone else wrote when I have the HD 800 and HD 800 S myself
and can hear the differences with my own ears?

The bass of the HD 800 S has more sub bass and the only explanation for that are the 2nd harmonics in the sub bass area which Tyll measured.

Not when talking about a point of engineering, i.e. that the perception of bass rather than the bass response itself is increased - it's a technical explanation (and a valuable insight) of why that is the case with the HD 800 S. It's clearly explained why the engineering limitations of open-back design lead Sennheiser to find another solution to 'warming up' the sound signature of the headphone.

Exactly. When most people hear/read the word distortion they think of very audible effects like driver breakup. Second harmonic distortion simply isn't that sort of 'audible' distortion. However, it is still technically speaking a distortion, and as Tyll says, if you know what you're listening for it can be heard.

And in this specific case Sennheiser produced solid results. I wonder just how many here correctly identified the warmer sq as a consequence of intended distortion? On the other hand, how many can hear it because they were told it's there. So we've come full circle: if you liked the sound before Tyll's review, you will continue to appreciate the S's sonic attributes, if you didn't, now you can point to something more concrete, real or imagined.

The HD 800 S is still on a decent level in terms of harmonic distortion. Particularly compared to headphones like Abyss or Dharma. It's just not exactly as clean (in the bass) as the original HD 800.

...Tyll's review seems to confirm what most of us have been saying for awhile. The stuff about Senn using a little bass distortion to warm up the sound is interesting. I think Sorrodje found something similar. I honestly don't hear the distortion unless I try EQ-ing up the bass, so I guess I am wee bit deaf in that regard?...

...It's a neat trick, because it doesn't sound artificial at all. So while the measurements may tell you "this is distortion" your senses are saying "there's more bass below 40Hz here".

If you like the HD 800 classic from a tube amp then you really can't complain over the additional 2nd harmonic distortion in the HD 800 S as tube amps tend to **** out this distortion like there's no tomorrow. If you read Tyll's article on the matter he questions whether the distortion is actually better as the HD 800's 3rd harmonic is higher than the 2nd when each harmonic (2nd, 3rd, 4th) should fall at an even rate.

I think people worry a little too much about harmonic distortion because they affiliate it with clipping distortion or electrical guitar distortion pedals. Even order harmonics may be worrisome on something like a Grado where the bass distortion can be basically at 100% (like the PS1000) whereas the the THD on the HD 800 S at 20Hz is around 5%, and that's caused solely by the 2nd harmonic...

...A question to all those who have actually did a head-to-head:
Is the small loss of micro detail, soundstaging, and extra bass distortion absolutely worth it in the new 800 S, over the classic HD800?

I have some state that the classic was somewhat "cleaner", especially in the bass, has a more vast soundstage, and better micro detailing than the S, and that the S sounds subtly more ordinary and slightly lacking, more congested in the bass, and have actually sold or returned the S for these reasons...

Short answer: Be happy and content with the S.

I wouldn't say there is any loss of soundstaging. No one mentioned hearing the Bass distortion until after Tyll published his measurements. But you will hear it if you like to EQ the bass up 3 db or more. My guess is that the slightly better instrument separation on the classic that is SOMETIMES heard, is due to the very slight bass distortion of the S. But I wouldn't worry about it unless you are a real instrument separation freak. Mostly I only hear it in complex orchestral music... and it is only very small...

Well the HD800S has more bass than the regular HD800. And the HD800S high's (taming the 6k-range) are better balanced than the regular HD800 .
Yet people speak about the HD800s sub-bass a bit uncontrolled (adds a bit distortion). So I guess that I need a cable to balance that ...

I am curious about this experience of bass warming and whether or not it is due to distortion or just increased amount. I don't understand whether I could possibly be hearing distortion due to the volume at which I listen, which I think doesn't often go above the low to mid seventies db range. According to Tyll's data, such as this:

http://www.innerfidelity.com/images/SennheiserHD800Ssn01070.pdf

...it doesn't seem likely that I am hearing what must be under 1% distortion at the very lowest hz, though maybe bass distortion is audible at these levels?

I've seen a huge assortment of modifications available for the HD800 cans, all the comparisons between HD800 and HD800S, and the mention by Tyll and others about the bass distortions on the second harmonic. However, I have not been having any luck coming across mods for the HD800S, perhaps to address the harmonic distortion (if it is even possible). Have I simply missed these mods or attempts to change/fix the harmonic distortion? Or has it been left largely untapped so far? If no one has really done it (or attempted to), I was wondering why?

It is my understanding that the harmonic distortion is the source of the perceived added bass. That is, to take it away, you lose one of the two benefits of the HD800S. Thus no one has attempted to remove it.

The suggestion is to use equalization with the original HD800 to equalize the bass to a higher, more correct volume - or to buy the new HD800S and accept both the distortion and bass as-is. If you were to buy the new HD800S and equalize the bass, it becomes more obvious that the bass is distorted. If you were to buy the new HD800S and remove the distortion, you have almost removed all the benefit of the new headphone...

The subbass-distortion isn't really a big deal. I barely notice it...

...The bottom end of the HD800S is actually less articulate due to the added 2nd harmonic distortion increase Sennheiser added when comparing to the HD800. You must have a golden or well trained ears to hear the difference in bass impact when comparing the two side by side (which I have done). Not to brag, but I hear it. It's very slim. The HD800's bass sounds tighter whereas the HD800S is looser. It's only by a hair though, like 2-3% difference. HOWEVER, due to this added distortion and lowered treble peak, the overall sound becomes much warmer! It's slightly equivalent to using a tube amplifier. It's warm and fuzzy. Voices and instruments has more weight to them...

I still prefer the regular HD800 + SDR (super dupont resonator), over the HD800 S.
The 800 + SDR is clearer, has a wider, more detailed soundstage, and tighter, cleaner bass.
To my ears the 800 S is slightly less clear, more constricted, and slightly looser than the 800 + SDR.
The 800 S, to my ears, believe it or not, also seems slightly peakier around 7 khz - 8 khz, which is somewhat annoying to my ears.
Compare the innerfidelity frequency response graphs of the stock 800 to the 800 S, and you will see that the 6khz peak is reduced on the 800 S, but the treble isn't as clean and smooth at other frequencies, such as 7-8 khz, where the S is actually peakier compared to the stock 800, plus, the impulse response of the 800 S isn't as clean as the 800, and of course the bass distortion is much higher.
HD800 + SDR is also MUCH less expensive than 800 S.
I was surprised myself when I saw those graphs and compared them!
I can also hear it as well.
On the other hand, the 800 + SDR is still somewhat harsher and colder sounding than the 800 S, but, overall I do prefer the tradeoffs that my 800 + SDR offers over what the 800 S offers.
My 2 cents.

...I think the greater slam of the elear might win me over, especially as you can only eq the bass so far on the HD800S before you notice an unacceptable degree of distortion...

The low 2nd order harmonic distortion (along with frequency response) probably contributed to the sterile analytical sound of HD800...

...With the S, I believe sennheiser tweeked up the 2nd harmonic distortion to make it sound more organic/euphonic...

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Given how it's become the overwhelmingly prevailing explanation for the sonic differences between these two models, I think it's quite fair to revisit this, given what we've measured.

Again, there are still a few more brand new Sennheiser HD800's to measure, which we'll do posthaste.

 

[Sorrodje]

https://www.head-fi.org/threads/sen...post-for-summary.795365/page-17#post-12350999

I' don't like to give credit to myself but I can't resist :

In matter of bass, I'm sorry but I don't hear more bass. Neither did my mic, fortunately for me. Maybe my HD800 was already “more bassy” than the average HD800. Who knows? But as a matter of fact my HD800S#493 does not offer more bass than my #17002 HD800. Even more, my critical listening tests make me think that the HD800S bass is tighter, maybe cleaner and less mid bass centric. Extension seems to be actually improved. Overall, the HD800 and HD800S low register are very similar to my ears.

Seems I didn't hear so much difference in bass and even if @jude's measurements would have confirmed increased distorsion, my opinion wouldn't have change. I never heard any specific bass bloom/bloat with my HD800S. Only a slight loss of definition and instrument separation with complex music. This opinion didn't change after Tyll's review.

I'm amongst the people who measured the HD800S and measured more distorsion than my HD800. I also measured my Modded HD800SDR and found more distorsion than stock as well but but nobody else confirmed that point. We're using amateurish rig and I wouldn't bet my salary on our distorsion results to be honest but sometimes we're more accurate in my opinion than a lot of so called pro measurements.

I choosed my HD800SDR and sold the HD800S though. it was an easy choice , considering the sound was similar enough to my ears and it was more easy to sell the brand new HD800S. it was 2 years ago and I never looked back.

 

[LarryMagoo]

All I know is I don't give a damn about what Jude or Tyll (who's inconsistent as hell!) says about the 800S.....I love the hell out of mine! I want a Closed can as well so looking forward to audition the HD820 vs Sony Z1-R.

Tyll has not had one nice thing to say about Sennheiser in a long time....especially since he took all their TOTL 'phones off his wall....wonder what's going on between the two???

In his short take on the HD 820 from CES, he described the Gorilla Glass as being Convex????

 

[swspiers]

All I know is I don't give a damn about what Jude or Tyll (who's inconsistent as hell!) says about the 800S.....I love the hell out of mine! I want a Closed can as well so looking forward to audition the HD820 vs Sony Z1-R.

Tyll has not had one nice thing to say about Sennheiser in a long time....especially since he took all their TOTL 'phones off his wall....wonder what's going on between the two???

In his short take on the HD 820 from CES, he described the Gorilla Glass as being Convex????

As opposed to concave? Yep, it's convex alright....

https://writingexplained.org/concave-vs-convex-difference

 

[casper3127]

As opposed to concave? Yep, it's convex alright....

https://writingexplained.org/concave-vs-convex-difference

Just the opposite I think... It's concave.

 

[SilverEars]

Jude, I'd like to see HD800 and the 800S frequency response side by side and overlapped.

 

[LarryMagoo]

The Glass on the HD 820 is Concave...Tyll called it Convex...that is simply wrong

 

[csglinux]

Depends on your perspective, I suppose It has to be concave from the position of the sound waves inside the earcup. From our perspective, being outside the earcup, it's convex.

 

[swspiers]

Just the opposite I think... It's concave.

LOL, not only am I wrong, but I'm wrong while being a smart-ass. Great...

 

[joseph69]

As opposed to concave? Yep, it's convex alright....
https://writingexplained.org/concave-vs-convex-difference

It's concave.

The Glass on the HD 820 is Concave...Tyll called it Convex...that is simply wrongUOTE]Correct.

 

[swspiers]

It's concave.

No need to pile-on, ol' buddy

 

[joseph69]

No need to pile-on, ol' buddy

Sorry.

 

[Swiftfalcon]

All I know is I don't give a damn about what Jude or Tyll (who's inconsistent as hell!) says about the 800S.....I love the hell out of mine! I want a Closed can as well so looking forward to audition the HD820 vs Sony Z1-R.

Tyll has not had one nice thing to say about Sennheiser in a long time....especially since he took all their TOTL 'phones off his wall....wonder what's going on between the two???

In his short take on the HD 820 from CES, he described the Gorilla Glass as being Convex????

Reviewers need to be honest (to their opinion), they don’t owe nice words to companies. Tyll is just doing his thing...I think. He recently took out stax sr009 and focal utopia from his list. Sennheiser HD 600 is still on. So its all mixed.

 

[swspiers]

I read this thread because it's interesting. And my hat's off to Jude and Tyll for what they do. I wouldn't do it: endure the slings and arrows of cascading opinion, all in an effort to provide us with meaningful analysis to help inform our decisions and enjoy this hobby.

Anyway, what I hope doesn't get lost in all of this is that the 800S's are spectacular headphones, and for me, on-par with some of the greatest speaker systems I've heard: Maggies, B&W, Ohm, and Apogee's, to name drop a few. I find little, if any, fault with these cans, regardless of music genre, equipment, or source material. They are an absolute pleasure to wear and listen to, for hours.

Oh, and in my 54 years of stomping the Terra, I have yet to hear a graph. Ever...

 

[james444]

The output impedance of the Audio Precision APx1701 is ≈0.13 Ω.

More food for thought...

Without knowing the output impedance (OI) of sources other reviewers used to perform their DIY-measurements and listening tests, let's take a look at one of the most popular amps for the HD800 / HD800S: the HDVD800.

According to this post (and others I've found), Sennheiser deliberately designed the HDVD800 with an OI of 43 ohms, to warm the HD800 up a bit. Thing is, even though nominal impedance of the HD800 / HD800S is 300 ohms, their impedance curve has actually a massive bump in bass around 100Hz, so driving them from a higher OI source will make them sound slightly warmer and perhaps a bit easier to listen to.

However, higher OI also means lower electrical damping, and as a result, slightly less control of the driver and slightly more distortion. I haven't found any measurements for the HD800 or HD800S in that regard, but this post demonstrates the effect nicely for the 250 ohms DT880 Pro.

So, considering that the damping factor of a HDVD800 driving the HD800 / HD800S is about 330 times lower than that of your Audio Precision APx1701, the listener may hear the headphones as both slightly bassier and less controlled than what your measurements would suggest. Moreover, even a small difference in THD between the HD800 and HD800S (provided there is any in the first place) might increase too, with higher output impedance.

As I said, just food for thought... particularly for those thinking the matter is straightforward and prematurely conclude that the emperor has no clothes.