[james444]

It seems pretty clear to me at this point -- based on the measurements (by us and others), based on feedback from Sennheiser, and based on feedback from several acoustical engineers in the audio industry not in the employ of Sennheiser -- that the assumption that Sennheiser added harmonic distortion (specifically, H2) to the Sennheiser HD800S is not accurate.

Thanks Jude, for providing THDs and going to great lengths investigating this matter. Personally, I never assumed that Sennheiser added distortion intentionally, but in light of the number of higher THD measurements for the HD800S out there, I thought it might simply be a by-effect of changes in acoustic damping via the HD800. However, at this point it's pretty clear that THD in general and H2 in particular don't show any significant differences on your high-grade measurement rig.

As for the others who consistently measured higher THD for the HD800S, I still have my doubts that such unanimous results can be sufficiently explained by higher ambient noise or simply by "inferiority" of DIY rigs... so I'll keep on wondering and probably bothering people with more questions. Tbh, I hoped that Tyll would join the discussion to shed some light on discrepances from his pov, but sadly it seems this might not happen.

Speaking of which, I've been able (with help of google search) to clear up one peculiarity about Tyll's THDs, those strange spikes you pointed out at 200 Hz and 2 kHz:

There are two spikes at 200Hz and 2kHz in THD in all plots, this is an artifact of the tester changing ranges at those frequencies.
Read more at https://www.innerfidelity.com/conte...tortion-plus-noise-part-2#fvv0KkrsJtp6rScg.99

So the next question is why different setups such as the one at Innerfidelity are showing a difference and this one isn't. I don't know whose is correct but the answer to why there is a difference is worth knowing.

+1

DIY measurement really shouldn't hold any weight in any discussion for a high end stock product, they might be useful to help visualize differences made due to modding and such.

This discussion has always been about differences observed on the same DIY rig. If the rigs in question were not up to the task of telling these differences reliably, they'd neither be useful to visualize differences caused by modding.

That said, Sennheiser, add some damned bass to your open headphones please. Just don't even THINK of using distortion to get there. LOL

With open headphones, the driver usually has a primary resonance between 60 and 150Hz (it's about 110Hz on the HD 800), below the primary driver resonance, driver efficiency will evermore reduce as frequency lowers. The result is loss of low frequency extension. Bottom line: there's not much Sennheiser can do to increase bass response of the HD 800.
Read more at https://www.innerfidelity.com/conte...uland-french-diy-response#AS2C8pZQftCLb4Ld.99

 

[amartignano]

Thanks Jude for clearing that up. You put a lot into this research. I think we can put to rest the idea that they added bass with distortion, and that Sennheiser wouldn't admit that if they did. Users who'd claimed measuring distortion meant well, no hard feelings. That said, Sennheiser, add some damned bass to your open headphones please. Just don't even THINK of using distortion to get there. LOL

The 800S has perfect amount of bass to me and my concert hall experiences. Please Sennheiser don't add unnecessary colored behavior to your open headphones

 

[caenlenfromOCN]

The 800S has perfect amount of bass to me and my concert hall experiences. Please Sennheiser don't add unnecessary colored behavior to your open headphones

If it is already perfect for you, why worry what Sennheiser will do to it? It most likely will last you a life time...

 

[amartignano]

If it is already perfect for you, why worry what Sennheiser will do to it? It most likely will last you a life time...

Did you saw the quote? It was an ironic response to Mark Up post
Nevertheless, I'm always curious about new achievements

 

[caenlenfromOCN]

Did you saw the quote? It was an ironic response to Mark Up post
Nevertheless, I'm always curious about new achievements

Oh I see, sorry I misread lol

 

[TenMoonsNorth]

Spoiler

Hey Jude, just wanted to say its really impressive to see the lengths and expenditures you have gone through to have the biggest baddest measurement rig around for us hobbyists to get a crucial data point from a rig that dwarfs many of the hobbyist rigs out there. While I'm sure many DIY rigs take their systems as far as they can, in the end they fall far short of what your fully loaded AP system can accomplish. The field of measurements really is a wild west and I think what you, Tyll, and Olive are doing are pushing towards an eventual mind-meld of standards in the community. This period of "measurement-doubt" really is short-lived in the scheme of our hobby. These measurements seem to indicate quite handily that while others can measure noise floor and THD to a certain depth, they will always cap out higher than your uber AP system, which as we see shows you consistently -35 dB lower down than all the competition. Keep at it and I think this hobby will greatly benefit from your efforts! To use a quote with subtle complexity but much depth, "victory belongs to the most persevering."

The noise floor is not relevant. Multiple people, including innerfidelity, have consistently shown the HD800S to have more distortion than the HD800 on the same setup. If this was just a case of noise floor then you wouldn't be seeing this and those setups have already demonstrated to have a low enough noise floor to show distortion below <0.5%.

The question is, assuming there is no difference, why some setups show a difference and this one doesn't. Just saying well this one is more expensive and has a lower noise floor is not the answer.

 

[music_man]

I was wondering why Jude and Company have gone to such lengths to test these. I have not heard them. Are they really special? I mean there are much higher end headphones. I could see testing the heck out of the SR009 or something but I have no idea why these are of so much interest not having heard them. I have the 800 but not 800s. I do not really care for the 800 would the S change my mind most likely? I honestly prefer the HD650 from this brand. Well it has recently come to light I do not prefer highly technical headphones. So that probably explains why I do not understand the hype. I am currently enjoying the Z1R so that probably speaks volumes about me. The Z1R was honestly barely noticed compared to these. I guess most people prefer a much more exacting headphone. I have no doubt these are great I just have no experience with them. If I did not care for the 800 is the S built upon that or different entirely? Sorry for so many questions. It is no big deal to run over to Music Direct and get them if you think they will impress me the Sony being my thing lately. Thanks

 

[Snowpuppy77]

I was wondering why Jude and Company have gone to such lengths to test these. I have not heard them. Are they really special? I mean there are much higher end headphones. I could see testing the heck out of the SR009 or something but I have no idea why these are of so much interest not having heard them. I have the 800 but not 800s. I do not really care for the 800 would the S change my mind most likely? I honestly prefer the HD650 from this brand. Well it has recently come to light I do not prefer highly technical headphones. So that probably explains why I do not understand the hype. I am currently enjoying the Z1R so that probably speaks volumes about me. The Z1R was honestly barely noticed compared to these. I guess most people prefer a much more exacting headphone. I have no doubt these are great I just have no experience with them. If I did not care for the 800 is the S built upon that or different entirely? Sorry for so many questions. It is no big deal to run over to Music Direct and get them if you think they will impress me the Sony being my thing lately. Thanks

Sure nice to have all these options as because of our variations in taste. All these options is what makes this hobby fun for me. I like a neutrality in headphones and speakers (at least what I perceive as neutral). I like bass extension and I want a kick drum in rock music and bass drum in classical to punch with dynamicism yet lots of inner detail. But I do not like warm or bloated bass as it smears detail and sounds off balance and less glorious with the best quality recordings. When playing the my HD800S on my Mapletree Ear+ tube amp and Asgard 2 I felt they had good balance but were a little warm or wooly in the bass. With my Ragnarok the bass has tighten up and seems ideal to me. My Shure 940 headphones are less warm in bass than the HD800S. The Shure 840s that I gave my daughter are a little more warm in the bass than the HD800S. When I heard the HD800 and HD800S side by side on the new Senn amp at the last RMAF CanJam I thought the HD800S sounded better in every way. I do prefer more bass then what I heard in the HD800 while the HD800S seems just right to me with a powerful amp. That said I was still very impressed with the original HD800 but am very glad I got the HD800S.

 

[SilverEars]

Sure nice to have all these options as because of our variations in taste. All these options is what makes this hobby fun for me. I like a neutrality in headphones and speakers (at least what I perceive as neutral). I like bass extension and I want a kick drum in rock music and bass drum in classical to punch with dynamicism yet lots of inner detail. But I do not like warm or bloated bass as it smears detail and sounds off balance and less glorious with the best quality recordings. When playing the my HD800S on my Mapletree Ear+ tube amp and Asgard 2 I felt they had good balance but were a little warm or wooly in the bass. With my Ragnarok the bass has tighten up and seems ideal to me. My Shure 940 headphones are less warm in bass than the HD800S. The Shure 840s that I gave my daughter are a little more warm in the bass than the HD800S. When I heard the HD800 and HD800S side by side on the new Senn amp at the last RMAF CanJam I thought the HD800S sounded better in every way. I do prefer more bass then what I heard in the HD800 while the HD800S seems just right to me with a powerful amp. That said I was still very impressed with the original HD800 but am very glad I got the HD800S.

Neutral? Don't make me laugh. People have to use vague term like technical when regarding the HD800? It's not balanced, and the characteristic is dry, clinical, and people look for the right amp/dac combo tells you much about the tuning.

The point is, it's not necessary to draw so much attention on this thread for this incidence(here are many threads here). Jude is able to concentrate on other headphones as well. I'd like to see many measurements of many other headphones by him, building a library like Tyll. Given he points out that his rig is that precise, why not provide the service to the community? We'd really appreciate it.

 

[Snowpuppy77]

Neutral? Don't make me laugh. People have to use vague term like technical when regarding the HD800? It's not balanced, and the characteristic is dry, clinical, and people look for the right amp/dac combo tells you much about the tuning.

The point is, it's not necessary to draw so much attention on this thread for this incidence(here are many threads here). Jude is able to concentrate on other headphones as well. I'd like to see many measurements of many other headphones by him, building a library like Tyll. Given he points out that his rig is that precise, why not provide the service to the community? We'd really appreciate it.

I am not talking about the HD800. I am talking about the HD800S. They sound significantly different. And yes the HD800S sounds balanced in my opinion. My opinion on that is just as valid as yours. Remember I said "(at least what I perceive as neutral)".

 

[amartignano]

Neutral? Don't make me laugh. People have to use vague term like technical when regarding the HD800? It's not balanced, and the characteristic is dry, clinical, and people look for the right amp/dac combo tells you much about the tuning.

The point is, it's not necessary to draw so much attention on this thread for this incidence(here are many threads here). Jude is able to concentrate on other headphones as well. I'd like to see many measurements of many other headphones by him, building a library like Tyll. Given he points out that his rig is that precise, why not provide the service to the community? We'd really appreciate it.

I agree with @Snowpuppy77, Hd800S sounds neutral to me, even when I listen to them attached to my smartphone (yes I do it).

 

[Mark Up]

I understand that open cans are more difficult to get bass extension from. I don't expect Fostex TH type subs from the Sennheiser open. That said, they can do better. If you buy a pair of stock Audio Technica ATH-R70x and put on tracks with very low HZ sub bass content you barely hear on the HD650, you'll hear it there. Kelis - The Weekend - is my favorite track. There are pre-choruses in the arrangement where she says "...and the beat goes, boom" and the first set of low 808 sub booms are audible in any headphone. The second set goes down to 17 hz and has almost no harmonics in higher octaves. Meaning, if your subwoofer or headphones don't reproduce stuff well below 20-30 hz, you're not going to hear it. It's barely audible on the HD600, a little better on the HD650 and you easily hear it on sub bass cannons like the Fostex TH, Meze 99, Sony MDR-1A, etc. Play it on the ATH-R70x and it's half way between the HD650 and the Meze 99, definitely there, you really feel it. Those are VERY open cans. They have a modest 45 mm driver. That's also with stock velour pads, that aren't unusually shallow or deep or other tricks done to enhance bass. If they made pads that actually were designed to enhance bass, they could probably get them close to the Meze 99 in sub bass. It can be done. Some MrSpeakers AEON Flow Open say they get response like this as well. That is hardly a distorted mess of a headphone. The sound is warm yet pristine, the same with the ATH-R70x. The ATH lacks some high mids, but that is not due to the bass response in those at all.

 

[vrln]

Neutral? Don't make me laugh.

I think the big problem is that the word "neutral" is such a can of worms when it comes to headphones. People use the word a lot (including me), but what do we actually mean by it? Neutrality is kind of agreed upon when it comes to speakers, but headphones are quite a different beast due to the way the drivers are aligned/ear shape affecting tonality and so forth. Headphones from different manufacturers seem to target very different frequency responses, it´s all over the place. There´s just much more variation than in the speaker world. I for example noticed at some point that what I meant when I stated neutral is actually more or less the same as "what full range studio monitors sound like in near field listening, including the fully out of head imaging". If you look at headphones from that definition I´d still claim the HD 800 S are the most neutral headphones I´ve ever heard since they get closest to a speaker like sensation so far despite the bright leaning tonality.

 

[amartignano]

I think the big problem is that the word "neutral" is such a can of worms when it comes to headphones. People use the word a lot (including me), but what do we actually mean by it? Neutrality is kind of agreed upon when it comes to speakers, but headphones are quite a different beast due to the way the drivers are aligned/ear shape affecting tonality and so forth. Headphones from different manufacturers seem to target very different frequency responses, it´s all over the place. There´s just much more variation than in the speaker world. I for example noticed at some point that what I meant when I stated neutral is actually more or less the same as "what full range studio monitors sound like in near field listening, including the fully out of head imaging". If you look at headphones from that definition I´d still claim the HD 800 S are the most neutral headphones I´ve ever heard since they get closest to a speaker like sensation so far despite the bright leaning tonality.

Interesting point of view.

 

[jude]

The noise floor is not relevant. Multiple people, including innerfidelity, have consistently shown the HD800S to have more distortion than the HD800 on the same setup. If this was just a case of noise floor then you wouldn't be seeing this and those setups have already demonstrated to have a low enough noise floor to show distortion below <0.5%.

The question is, assuming there is no difference, why some setups show a difference and this one doesn't. Just saying well this one is more expensive and has a lower noise floor is not the answer.

Noise level is relevant. Let's talk about THD and THD+N -- that's total harmonic distortion, and total harmonic distortion plus noise, these being two different kinds of measurements.

With THD+N, noise is part of the measurement. AP defines THD+N as "the sum of all the harmonic distortion products in a measurement, as opposed to selective harmonic distortion, which measures discrete harmonic products separately. THD+N adds noise to this figure." Further:

...In analysis, the bandwidth is usually controlled using filters; the stimulus tone is removed, and the signals that remain are reported as one measurement. These remainders are the total harmonic distortion (all harmonics within the bandwidth), noise from the DUT, and any other signals such as hum, spurious signals and other distortion products.

THD+N is an excellent and trusted quick check on several aspects of a system’s overall performance, a quick, easy and robust mark of quality. However, because of its lack of discrimination, THD+N is not always the most useful measurement for troubleshooting.

You can see, then, if the system in question is measuring THD+N, then noise should be considered. From the Audio Measurement Handbook by Bob Metzler:

...Note that many older analyzers of the THD+N architecture are labeled THD on their panel and many people refer to a THD measurement when they really mean the THD+N technique.

That book has been around for many years, so let's discuss THD measurement (as opposed to THD+N). For a THD measurement (not THD+N) in Audio Precision's APx, what's being measured are only the bins that contain harmonic distortion products. If that's the method being used, does that mean exogenous noise has no effect? No, that's not what it means. Especially in an acoustical measurement, noise can still affect a THD measurement. Even if measuring only the bins that contain harmonic distortion products, external energy that reaches the mics and gets into those bins can be reflected in the THD calculation. This can be more evident, for example, if the FFT length is short and the bins are wide.

For passive headphones, we go with THD. InnerFidelity measures THD+N. (As for anyone else, I can't account for the different software various people are using and how distortion measurements are determined across the many different apps used.) I do believe Tyll mentioned in a recent post that InnerFidelity will soon be switching to Listen, Inc.'s SoundCheck measurement system, which is an excellent system, especially for electro-acoustic test. When he makes the switch, perhaps he'll continue to stick with THD+N to represent the distortion of passive headphones, but I am guessing that perhaps THD will come to the fore at InnerFidelity for that purpose after the system changeover.

Again, noise can definitely affect THD, and especially THD+N, measurements.

(Perhaps we can run a special set of measurements with the HD800 and/or HD800S to illustrate this, when time permits.)