[xnor]

   
1.The housing is simple a quasi helmholtz resonator , work to trap back waves, not  just "fullmetal".  and its actually abs plastic frame combine metal grill.
 
2.This kind design somehow sensitive to system's actual damping (not just damping factor number) , clearly some low output impedance amp not suit this.

 
That's from the T70 but it should apply to all T models, shouldn't it?
 
1) There's a reason other manufacturers use some kind of thin fleece behind the diaphragm or mesh, or paper-like material because that doesn't seem to cause resonance problems.
If Beyerdynamic insited on metal housing then they still could have "coated" the inside with some kind of fleece.
 
2) Low output impedance improves damping.
What a high output impedance is gonna do, is basically work like an EQ with a peak filter at around 100 Hz. Of course if you boost the bass then treble peaks will be noticed less. There will also be a small increase in distortion, since the driver can ring more freely.

 

[gatucho]

I understand the idea of having an ideal FR target as a primary design goal, although I think that there are other characteristics that would be valuable to asses.
 
My main criticism is that whereas "flat" is easy enough to justify and characterize, the flat equivalent for HP is not clear. As you say, there are several ONGOING efforts to determine this ideal FR.
 
A question: an HP with a perfect FR (using whatever current standard) would sound identical as a set of "flat" speakers? I just don't think so, that is my hypothesis. Unless yours is that they would, then why are we striving for this "speaker like" goal. Maybe there is something more for HP than sounding like speakers.
 
Another question: a set of flat speakers cannot be told apart from the live performance? Only THIS would comply with your own definition of fidelity. "Flat speaker sound" is not the end of the line. I haven't heard a flat speaker system, but I would think that room acoustics also intervene. Then, which are the equivalent to proper room acoustics for HP? I believe that there is much more than DF equalization to this since I think that we can still distinguish HP from speakers.
 
You should keep in mind that not all research is disclosed in public forums such as the AES journals, much research done by the companies behind the curtains and never released to the public, except as technology demonstrations without the theoretical/experimental development. This only makes sense, why make public something which cost you so much? I see this everyday on my line of work. What I'm saying is that, whether you like it or not, companies such as senn, beyer or audeze are likely investing some money on defining a FR goal. It is normal that such FR evolves as times passes by, the hd6xx are quite old now, it is reasonable to think that senn improved/modified their FR target.
 
The differences across the lineup of the manufacturers I wouldn't think that are explained only on a technical basis, there surely are market elements also.
 
So headroom FR measurements are bogus and Tyll's are perfect.... INCONSISTENCY I say. When you have several data sources which don't agree you just don't take the one you personally prefer as the correct one, that wouldn't be "objective". Do you think that Tyll's are better? Based on what? Methods and equipment are not sufficient to determine this. In the scientific community repeatability and numerous third party reproductions, i.e. CONSISTENCY, are needed to ascertain that something is true.
 
The same goes for the CSD measurements, even if there was a good understanding of how those CSD must look like, other than "common sense" and dogmatic asseverations made by those "who know".
 
One must trust the knowledge produced by science, however who is to say what it science and what pseudo-science. Using scientific "tools" does not instantly makes something into science. Proper use of the scientific methods does.
 
I believe that at this moment there is still no agreement, and I mean agreement in facts not of the community, of what is technically "correct" for HP. When I buy a senn or any other flagship what Im buying is what their current research and state of the art of the art points to be the ideal.
 
I'm not trying to bash the original article. However, the data points, the deductions and the methods still require a LOT of development for they to support statements such as "under engineered mess" or that HP A is four alphabet letters better than HP B. That would be almost as silly as saying that a better silver and gold 1.5m cable will improve the sound of my HP because some MEASURABLE improvement in some metric. Come on, when do objectivists, one of which I pretend to be, became so skewed?

 

[castleofargh]

most FR critics here are not about how accurate or neutral it is, but about avoiding huge pics or dips that never equal to good sound for people. the more spiky the FR the less people are susceptible to like it. Olive&Welti(my new prophets) confirmed that but it was a given for me that a huge and hard variation in frequency cannot sound natural or nice.
 
 
 
the purpose of HIFI (high fidelity) is to have something that can accurately reproduce sound. measurements are checking just that. all the mess with measurements is about interpretations. FR compensation, smoothing, irregular frequency axis and what have you are not the measurements fault. as for this work, the rankings need some refinements, we all agree on this even the creator himself. but wrong conclusions or conclusions that you disagree upon don't make the measurements to be wrong.
like any kind of classification, it must start somewhere. and the better we can define a phone, the more realistic and useful the classification becomes. there is no way around it, it has to start somewhere and that somewhere will be messy and inaccurate at first. it doesn't mean that it's going nowhere.
when Tyll had 3 graphs they had no purpose, now that he has a lot of those done(I expect) pretty much the same way, the result is of great value.
I take this effort the same way, it's only the messy beginning of something great.
 
 
 
 
@Sorrodje: I know 2 cases where bad specs can (not will) sound pleasant(not good):
-tube distortion in amps.
-low frequency distortion in phones.
for pretty much everything else bad specs equal audio trouble in a way or another and won't make a sound we will prefer to the more accurate one. even my 2 examples give usually a bad sounding result but some hazards happen when it's actually nice to hear.
good specs mean more accurate sound, if the audio engineer didn't work on the album to make it sound good out of Beats by Dre, then we will get the best of a cd with accurate sound and good specs.
 
but all this is only about retrieving the signal, so if we have spent our childhood listening to some crappy gear, we will probably have a thing for that crap sound over the accurate one.
ps: t'as le hifimediy?

 

[Claritas]

There are plenty of issues that I consider red herrings, such as arguments about the terms "reference" and "flagship" and anything about prices. If we take the presentation seriously and try to work with it, maybe we can make use of it in improving both our personal notions and best corporate practices. I am reluctant, however, to esteem it much until the author is candid about his actual listening experience with all of those models.

 

[Sorrodje]

ps: t'as le hifimediy?

 
Nan mais je ne suis pas aux pièces.
 
About correlation between measures and Listening experience , I've no doubt there's listenable technical flaws but how can we determinate which technical flaw makes clearly this pair of headphones unlistenable ? 
 
ed10 seems to have very important technical flaws. So does everyone find this headphone even less good that a Beats Solo ? no definitely no . Some people hates it and some other people fint ed10 extremely good. So ? What's the correlation ?  

 

[Claritas]

  when Tyll had 3 graphs they had no purpose, now that he has a lot of those done(I expect) pretty much the same way, the result is of great value.
 
I know 2 cases where bad specs can (not will) sound pleasant(not good):
-tube distortion in amps.
-low frequency distortion in phones.
for pretty much everything else bad specs equal audio trouble in a way or another and won't make a sound we will prefer to the more accurate one. even my 2 examples give usually a bad sounding result but some hazards happen when it's actually nice to hear.

 
What you wrote about the three graphs is interesting and common in scientific progress. Do you remember which graphs they were, because I'd like to learn more.
 
I experience organ and chamber (string) music played on some Grados as pleasantly distorted.

 

[castleofargh]

 

  when Tyll had 3 graphs they had no purpose, now that he has a lot of those done(I expect) pretty much the same way, the result is of great value.
 
I know 2 cases where bad specs can (not will) sound pleasant(not good):
-tube distortion in amps.
-low frequency distortion in phones.
for pretty much everything else bad specs equal audio trouble in a way or another and won't make a sound we will prefer to the more accurate one. even my 2 examples give usually a bad sounding result but some hazards happen when it's actually nice to hear.

 
What you wrote about the three graphs is interesting and common in scientific progress. Do you remember which graphs they were, because I'd like to learn more.
 
I experience organ and chamber (string) music played on some Grados as pleasantly distorted.

arf no I meant when he had only measured 3 headphones. sorry it wasn't clear. my point being, as more phones are added, the work itself will become a source of intel for comparison and errors will become visible from disparities/errors on a given criteria.

 

[xnor]

 
My main criticism is that whereas "flat" is easy enough to justify and characterize, the flat equivalent for HP is not clear. As you say, there are several ONGOING efforts to determine this ideal FR.

Both speakers and headphones were tested with real people. With speakers the preference goes towards flat (maybe with a downwards tilt towards the highs, but flat/smooth FR nevertheless). With headphones see the curve published by Olive/Welti.
If you test enough trained listeners you will come up with a target curve that is generally preferred.
 
 

A question: an HP with a perfect FR (using whatever current standard) would sound identical as a set of "flat" speakers? I just don't think so, that is my hypothesis. Unless yours is that they would, then why are we striving for this "speaker like" goal. Maybe there is something more for HP than sounding like speakers.

No, with headphones you got the unnatural separation between channels and no room acoustics, hence they will always sound different. That doesn't change anything though.
 
Even if an agreed upon curve were not the absolute perfect curve, it would still have benefits. One pretty big deal would be that any kind of signal processing could be tuned based on that curve. Right now, something like HRTF processing is hit and miss, because different headphones have completely different frequency responses. A more standard FR would improve this.
 
 

Another question: a set of flat speakers cannot be told apart from the live performance? Only THIS would comply with your own definition of fidelity. "Flat speaker sound" is not the end of the line. I haven't heard a flat speaker system, but I would think that room acoustics also intervene. Then, which are the equivalent to proper room acoustics for HP? I believe that there is much more than DF equalization to this since I think that we can still distinguish HP from speakers.

Stereo can be told apart from a live performance because it is only 2 channels and most of the information is already lost during recording.
High fidelity is about reproducing the recorded signal accurately. If the engineers capture/mix/master crap then the listener will hear crap.
 
Yes, room acoustics intervene, hence the treatment of real hifi rooms (again towards an ideal). In a well treated room you can get a pretty accurate response. This doesn't concern headphones because there's no room. Well, there are other things like pinna/ear-canal resonances. Smart manufacturers will tune their headphone constructions to control for this as far as possible, so you'll get more consistent frequency response across different heads/ears.
 
 

You should keep in mind that not all research is disclosed in public forums such as the AES journals, much research done by the companies behind the curtains and never released to the public, except as technology demonstrations without the theoretical/experimental development. This only makes sense, why make public something which cost you so much? I see this everyday on my line of work. What I'm saying is that, whether you like it or not, companies such as senn, beyer or audeze are likely investing some money on defining a FR goal. It is normal that such FR evolves as times passes by, the hd6xx are quite old now, it is reasonable to think that senn improved/modified their FR target.

Afaik PSB is working with the NRC and their new headphones follow the Olive/Welti curve much more than DF/FF or such stuff.
 
Beyerdynamic says: "Since the mechanical and electronic options for changing the frequency response of headphones are limited, the equalisation cannot be carried out perfectly. Different headphones are also adjusted to various tastes."
And I think that's exactly what is happening. For most models there seems to be little interest in accuracy. Different lines of models may have different target curves based on some marketeers ideas ("the headphones targeting the youth needs thumping bass", "the audiophiles want more detail so we give them a HD600 with a treble peak" etc.)
 
 

The differences across the lineup of the manufacturers I wouldn't think that are explained only on a technical basis, there surely are market elements also.

Yes, I guess we had the same though.
That's all the time I have to respond atm.

 

[xnor]

  ed10 seems to have very important technical flaws. So does everyone find this headphone even less good that a Beats Solo ? no definitely no . Some people hates it and some other people fint ed10 extremely good. So ? What's the correlation ?  

a) I'm not so sure about the "definitely no", but it depends on the Beats model.

b) Price and brand image.

 

[donthuang]

 
 
That's from the T70 but it should apply to all T models, shouldn't it?
 
1) There's a reason other manufacturers use some kind of thin fleece behind the diaphragm or mesh, or paper-like material because that doesn't seem to cause resonance problems.
If Beyerdynamic insited on metal housing then they still could have "coated" the inside with some kind of fleece.
 
2) Low output impedance improves damping.
What a high output impedance is gonna do, is basically work like an EQ with a peak filter at around 100 Hz. Of course if you boost the bass then treble peaks will be noticed less. There will also be a small increase in distortion, since the driver can ring more freely.

 
 
1. So its "tesla driver",  but not "housing" or "enclose" , i cant got what you meaning?
 
p.s. The mesh or paper-like  material is work as a acoustic impedance,  work a part of pressure chamber , the semi-seal space between ear and headphone.
       It's not prevent cause resonance problems or something else,but adjust the air volume. You can also take HD800's baffle the same thing , so its nonsense add damping here.
 
Back to beyer's , its "semi-open" type housing can take as a helmholtz resonant absorber,that's my point.
 
 
 
2.headphone driver is soft dome tweeter work in a condition make them full range ,  its somehow "now like" High damping form amp.
 
Headphone's 100Hz impedance peak somehow hint  those manufacturer try to "loose"   headphone's driver, (actually the driver's Fo here)
Also hint its merely  High Q  here, not simply a EQ filter.

 

[mikemercer]

Much enjoyed here as well

I second that!
 
A very interesting read, especially considering some of my reference systems!

 

[xnor]

 
1. So its "tesla driver",  but not "housing" or "enclose" , i cant got what you meaning?
 
p.s. The mesh or paper-like  material is work as a acoustic impedance,  work a part of pressure chamber , the semi-seal space between ear and headphone.
       It's not prevent cause resonance problems or something else,but adjust the air volume. You can also take HD800's baffle the same thing , so its nonsense add damping here.
 
Back to beyer's , its "semi-open" type housing can take as a helmholtz resonant absorber,that's my point.

It says "fullmetal housing" in the image.
 
I'm talking about the back of the diaphragm (where "fullmetal housing" points to in the image). This is metal in tesla drivers. Afaik no other driver/manufacturer uses that.
Also, the pressure chamber effect only works up to a certain frequency. Above that you will get resonances. That may be exactly what we're seeing in the measurements...
 
HD800 uses a mesh at the back in an open construction.
 
 

2.headphone driver is soft dome tweeter work in a condition make them full range ,  its somehow "now like" High damping form amp.  
Headphone's 100Hz impedance peak somehow hint  those manufacturer try to "loose"   headphone's driver, (actually the driver's Fo here)
Also hint its merely  High Q  here, not simply a EQ filter.

Headphone tweeters work full-range because of the better coupling. This means higher acoustic impedance, but that has nothing to do with electrical damping.
Yes, a high impedance peak points towards a very weak suspension and an overall underdamped system, which means that proper electrical damping (low output impedance) is even more important.
 
High output impedance with such a driver will effectively result in an FR change similar to a simple peaking EQ filter plus a small increase in distortion.

 

[donthuang]

  It says "fullmetal housing" in the image.
 
I'm talking about the back of the diaphragm (where "fullmetal housing" points to in the image). This is metal in tesla drivers. Afaik no other driver/manufacturer uses that.
Also, the pressure chamber effect only works up to a certain frequency. Above that you will get resonances. That may be exactly what we're seeing in the measurements...
 
HD800 uses a mesh at the back in an open construction.
 
 
Headphone tweeters work full-range because of the better coupling. This means higher acoustic impedance, but that has nothing to do with electrical damping.
Yes, a high impedance peak points towards a very weak suspension and an overall underdamped system, which means that proper electrical damping (low output impedance) is even more important.
 
High output impedance with such a driver will effectively result in an FR change similar to a simple peaking EQ filter plus a small increase in distortion.

 
1.About "fullmetal housing" , i guess you mean "pole plate" ?  That's is not much special in my view, i don't know why you think it cause resonance here.
The resonance in Tyll's measure  more like  diaphragm's break-up model lose control, wrong-damping.
 
 
2.Damping is interesting problem, headphone's diaphragm is still much lower mass  than loudspeakers (relative low Q here), I think its no harm to use acoustic damping properly . (hey, did i mention Grado here?)
 
The problem is damping factor is not always higher equal better, and its just a ratio number, not shows real "damping" situation, IMO, 6 to 7 is enough to headphone.
And this somehow hints why tube amp more popular in headphone's world, not those "good" soild stage amp.
 
Btw, higher acoustic impedance will just wipe the impedance peak , not boost it.
Strong magnet system > high bmf >relative lower acoustic impedance > cause those HiEND headphone's impedance peak.

 

[xnor]

   
1.About "fullmetal housing" , i guess you mean "pole plate" ?  That's is not much special in my view, i don't know why you think it cause resonance here.
The resonance in Tyll's measure  more like  diaphragm's break-up model lose control, wrong-damping.
 
 
2.Damping is interesting problem, headphone has its back-emf,  this is major factor decide "proper electrical damping" ,  lower the amp's  output impedance just short it, do you think its good?
 
Btw, higher acoustic impedance will just wipe the impedance peak , not boost it.
Strong magnet system > high bmf >  lower acoustic impedance > cause those HiEND headphone's impedance peak.

1. Kinda. As you can see it is more than just a pole plate as it would seal the back of the diaphragm if there weren't those holes. High frequency resonance will be caused here due to reflections just like the pinna causes reflections despite the much softer human skin compared to metal.
Regarding break-up: I doubt that they used worse diaphragms for the T models than for the DT models. And regarding damping: Tyll is using a low output impedance amp that will result in very high damping with the ~600 ohm T1.
 
2. Yes I think high electrical damping is good because:
Quote (me, from another forum):

The movement of the voice coil will generate back EMF which despite its name is not a force but a voltage with inverse polarity. From the point of view of the driver, a 0 ohm output impedance means you short it. So the driver will follow the input voltage exactly. With a perfect driver and perfect 0 ohm source this would yield a perfectly distortion-free output.
As soon as you increase the output impedance a fraction of the back EMF will counter the movement of the voice coil. So the driver won't follow the input voltage perfectly anymore. This increases nonlinear distortion, which no matter how nice (e.g. low order harmonics) will cause IMD as soon as >= 2 tones are present.

But the change in the frequency response will most likely be perceived much stronger than the small increase in distortion.
 
I think you're confusing acoustic impedance here. You want high acoustic impedance (seal!) even at low frequencies so that the little driver can effectively produce those low frequencies at high SPL. For example, if you don't put an in-ear correctly into your ear (no proper seal), the acoustic impedance will drop rapidly at lower frequencies - the result is extreme bass roll-off.
 
A strong magnet means low Qts (overall Q of the driver), a weak magnet means higher Qts. If the diaphragm can swing freely and ring very long then the Qms will be higher, which will result in a narrow and high impedance peak. But a higher Qms will also raise Qts a little bit.

 

[donthuang]

 
1. Kinda. As you can see it is more than just a pole plate as it would seal the back of the diaphragm if there weren't those holes. High frequency resonance will be caused here due to reflections just like the pinna causes reflections despite the much softer human skin compared to metal.
Regarding break-up: I doubt that they used worse diaphragms for the T models than for the DT models. And regarding damping: Tyll is using a low output impedance amp that will result in very high damping with the ~600 ohm T1.
 
2. Yes I think high electrical damping is good because:
But the change in the frequency response will most likely be perceived much stronger than the small increase in distortion.
 
I think you're confusing acoustic impedance here. You want high acoustic impedance (seal!) even at low frequencies so that the little driver can effectively produce those low frequencies at high SPL. For example, if you don't put an in-ear correctly into your ear (no proper seal), the acoustic impedance will drop rapidly at lower frequencies - the result is extreme bass roll-off.
 
A strong magnet means low Qts (overall Q of the driver), a weak magnet means higher Qts. If the diaphragm can swing freely and ring very long then the Qms will be higher, which will result in a narrow and high impedance peak. But a higher Qms will also raise Qts a little bit.

 
 
1. I don't think edge's reflection back-waves is  a serious problem, Edge just vibrations  when center dome moving fast , If  some back waves reflect , a multi-layer diaphragm can simply "block" it, its somehow not fit the creepy resonance in Tyll's measure.
 
Btw,i believe some dynamic  flagship's  A.O.C / acoustic openness coefficients already can equal planer headphone.
 
2. I think this dilemma determine by headphone manufacturers, so fixed the reply above. By all means, just ignore it maybe better.
p.s. Thanks correct about acoustic impedance.