[Hifihedgehog]

That's stretching the definition of the the equal-loudness curves though: it's just what the ear interprets as equal relative to sound level. It's not used in headphone design as far as I know. When you record music, there's no equal-loudness curve applied: it's just whatever the audio engineer deems may add for taste. So no, equating headphone response with equal-loudness curve and concluding it's neutral

However, yes, you're right: not HRTF, diffuse (or free) field equalizations is what I meant. They're the target response back then, but a few target responses have popped up, all of which don't incorporate the equal-loudness curves. The equal-loudness curves are present even if you're using a speaker or listening to an orchestra: it's not something that's to be corrected.

Equal-loudness curves can be used in any sound device to remedy the perception of sound response at lower volumes, and it is easy to see them being incorporated in the frequency responses of modern diffuse-field equalized headphones--that is the point. Tyll at InnerFidelity referenced its possible use in the Shure SRH-1540, but I believe it is also being more widely than that, by Sennheiser in their latest high-end headphones, by Philips in the Fidelio X2, and many, many others. Headphones in the past have relied on dead neutrality, such as the Sennheiser HD 600, which was designed to follow industry standard diffuse field equalization as closely as possible. Saying none of the newer variations of diffuse field equalization incorporate it is a misnomer because diffuse equalization has stayed relatively the same as a standard while manufacturers are compensating for something other than measured neutrality in their headphones' individual frequency responses. The problem is this unmodified diffuse field equalization does not work for listening pleasure at safe, normal listening levels, since at volumes lower than 120 dB, the level of bass and treble compared to midrange is perceived as compromised, and this is only exacerbated by headphones which lack the dimensional clarity and physical impact of speakers.


Now, it is very easy to see something uncannily reminiscent of equal-loudness contours in the sound responses of more and more modern headphones and the fact that many high-end manufacturers are tending toward this tuning makes sense. One prime example of this is the Harman Target Response Curve, of which Tyll at InnerFidelity is a huge proponent who believes it is the next big thing in the industry. In his descriptions of it, it is revealed that it was not developed to further the technical accuracy of diffuse field equalization but its primary objective was to find the most favored sound based on user feedback of pleasure for given modifications in frequency response. The optimal or most pleasureable curve is shown to have boosts in bass and treble which are located very, very closely to the same places that an equal-loudness contour would have them. Coincidence? I think not. Also, to correct what you said, an equal-loudness curve is not applied automagically just by playing back a recording, as it is an equalization technique which has to be consciously performed to simulate full loudness at volumes lower than 120 dB. One way equal-loudness curves have been applied in the past is through the loudness button, and there is a now trend to incorporate this through the mechanical tuning of headphones as well. To conclude, as I explained earlier, there is absolutely no reason why anyone cannot incorporate this curve in diffuse field equalized headphones. And from what can be seen, many manufacturers already gone ahead and done just that in the new target responses of their headphones.

 

[Nikori]

Hi guys! So after more than a week of owning these headphones I thought I'd update u guys with my thoughts on them. )
 
Initially, listening to them powered by the Dacmagic Plus alone (while waiting for my adapter to arrive) had me doubting my purchase. It sounded quite harsh in the treble region and I felt the music sounded pretty imbalanced. NOT impressed!
 
After receiving my adapter, I ran them through the O2 amp and difference was apparent. Imaging improved a lot and surprisingly, the harsh trebles were gone (except certain songs where the recording is harsh to begin with...). It was an obvious improvement that could be the result of "sound perception" since I pretty much believed the O2 would improve what I was hearing 

 
In comparison to the Grados, I would say the most noticeable difference is the increased soundstage, instrument separation, and imaging. It did sound brighter than my Grados as well. (Keep in mind that I use S-cush pads on my SR225e). However, I prefer my Grados while listening to classic rock and pop music since to me, they give more of a punch and more aggressive attack which just has me moving along to the music. The Senns can't quite achieve that level of intimacy unfortunately... The Grados make me feel like I'm playing with the band but listening through the Senns is like listening to live music in Albert Hall.
 
All in all, I'm really satisfied with my purchase as imo these headphones really complement each other.
 
And sincere thanks to all Head-Fiers. It may be hard to believe, but all my purchase decisions thus far have been made by reading the respective posts thoroughly. Never once auditioned a pair of headphones properly 

    
 
Have a great day!! )

 

[MWSVette]

  Hi guys! So after more than a week of owning these headphones I thought I'd update u guys with my thoughts on them. )
 
Initially, listening to them powered by the Dacmagic Plus alone (while waiting for my adapter to arrive) had me doubting my purchase. It sounded quite harsh in the treble region and I felt the music sounded pretty imbalanced. NOT impressed!
 
After receiving my adapter, I ran them through the O2 amp and difference was apparent. Imaging improved a lot and surprisingly, the harsh trebles were gone (except certain songs where the recording is harsh to begin with...). It was an obvious improvement that could be the result of "sound perception" since I pretty much believed the O2 would improve what I was hearing 

 
In comparison to the Grados, I would say the most noticeable difference is the increased soundstage, instrument separation, and imaging. It did sound brighter than my Grados as well. (Keep in mind that I use S-cush pads on my SR225e). However, I prefer my Grados while listening to classic rock and pop music since to me, they give more of a punch and more aggressive attack which just has me moving along to the music. The Senns can't quite achieve that level of intimacy unfortunately... The Grados make me feel like I'm playing with the band but listening through the Senns is like listening live music in Albert Hall.
 
All in all, I'm really satisfied with my purchase as imo these headphones really complement each other.
 
And sincere thanks to all Head-Fiers. It may be hard to believe, but all my purchase decisions thus far have been made by reading the respective posts thoroughly. Never once auditioned a headphone properly 

    
 
Have a great day!! )

+1  Welcome to the club.  I really like the HD700's too...​

 

[Mechans1]

I really like my HD700s as well and took a risk in buying them unheard.  In a kind or reverse psychology I thought they might be my cup of tea, given the concern of many posts regarding,  "treble peaks".  I like the so called analytic/detailed style sound, that many do not.  I was lucky, these are very satisfying. 
. 

 

[dazzerfong]

Equal-loudness curves can be used in any sound device to remedy the perception of sound response at lower volumes, and it is easy to see them being incorporated in the frequency responses of modern diffuse-field equalized headphones--that is the point. Tyll at InnerFidelity referenced its possible use in the Shure SRH-1540, but I believe it is also being more widely than that, by Sennheiser in their latest high-end headphones, by Philips in the Fidelio X2, and many, many others. Headphones in the past have relied on dead neutrality, such as the Sennheiser HD 600, which was designed to follow industry standard diffuse field equalization as closely as possible. Saying none of the newer variations of diffuse field equalization incorporate it is a misnomer because diffuse equalization has stayed relatively the same as a standard while manufacturers are compensating for something other than measured neutrality in their headphones' individual frequency responses. The problem is this unmodified diffuse field equalization does not work for listening pleasure at safe, normal listening levels, since at volumes lower than 120 dB, the level of bass and treble compared to midrange is perceived as compromised, and this is only exacerbated by headphones which lack the dimensional clarity and physical impact of speakers.


Now, it is very easy to see something uncannily reminiscent of equal-loudness contours in the sound responses of more and more modern headphones and the fact that many high-end manufacturers are tending toward this tuning makes sense. One prime example of this is the Harman Target Response Curve, of which Tyll at InnerFidelity is a huge proponent who believes it is the next big thing in the industry. In his descriptions of it, it is revealed that it was not developed to further the technical accuracy of diffuse field equalization but its primary objective was to find the most favored sound based on user feedback of pleasure for given modifications in frequency response. The optimal or most pleasureable curve is shown to have boosts in bass and treble which are located very, very closely to the same places that an equal-loudness contour would have them. Coincidence? I think not. Also, to correct what you said, an equal-loudness curve is not applied automagically just by playing back a recording, as it is an equalization technique which has to be consciously performed to simulate full loudness at volumes lower than 120 dB. One way equal-loudness curves have been applied in the past is through the loudness button, and there is a now trend to incorporate this through the mechanical tuning of headphones as well. To conclude, as I explained earlier, there is absolutely no reason why anyone cannot incorporate this curve in diffuse field equalized headphones. And from what can be seen, many manufacturers already gone ahead and done just that in the new target responses of their headphones.

You're make a correlative link with a causal link. You're gonna have to gimme some evidence to show that the Harman curve is modelled after both diffuse and the equal-loudness curve, because it doesn't: if it does incorporate it, it'll have significantly increased bass and treble, which we all know isn't true in the closest. It just so happens that, after subjective testing, most people who have participated in Harman's trials actually don't like more bass than the usual flat line. The reason for the extended bass is due to simulation of the boundary effect which increases bass in speakers.
 
I'll be honest, they vaguely resemble each other: you are cherrypicking parts to say they look similar. For one, the Harman curve rises to a 3khz peak: the equal-loudness curve goes down.

The problem about using the equal-loudness contours is that if we already apply that on the headphone end, we are in effect 'double-filtering' by both our brain and the headphones themselves. If you invert it, then you get rid of the filter that exists when you listen to everything not a headphone, thus destroying the element of our hearing.
 
It seems to me that you're mixing up causality and correlation, unless I'm mistaken. However, you are right in equal-loudness curves used as part of those 'loud' buttons in addition to brickwalling.

 

[Hifihedgehog]

  You're make a correlative link with a causal link. You're gonna have to gimme some evidence to show that the Harman curve is modelled after both diffuse and the equal-loudness curve, because it doesn't: if it does incorporate it, it'll have significantly increased bass and treble, which we all know isn't true in the closest. It just so happens that, after subjective testing, most people who have participated in Harman's trials actually don't like more bass than the usual flat line. The reason for the extended bass is due to simulation of the boundary effect which increases bass in speakers.
 
I'll be honest, they vaguely resemble each other: you are cherrypicking parts to say they look similar. For one, the Harman curve rises to a 3khz peak: the equal-loudness curve goes down.

The problem about using the equal-loudness contours is that if we already apply that on the headphone end, we are in effect 'double-filtering' by both our brain and the headphones themselves. If you invert it, then you get rid of the filter that exists when you listen to everything not a headphone, thus destroying the element of our hearing.
 
It seems to me that you're mixing up causality and correlation, unless I'm mistaken. However, you are right in equal-loudness curves used as part of those 'loud' buttons in addition to brickwalling.

Yes, it is a hypothesis, albeit well-researched, a hypothesis that will take time to be proved or disproved. If we did not take correlations out into the open and have them publicly scrutinized as we are doing now, underlying causation could never be identified or understood. Yet we need to seriously consider them, with adherents and detractors on both sides to tear the cases apart, so as to come to a final conclusion. Fortunately, this is no problem, or we would not be having this conversation to begin with.  
 
Now, I do not claim the Harman Target Response Curve is perfect, and I admit a bit of undue, inaccurate hyperbole in my claims. I should have more accurately stated that it is a step in the right direction, a direction Tyll puts a lot of stock in as well. Granted, there are quite a few issues people outside of Harman's testing are having when using the curve, such as underrepresented bass, so it is not without its quibbles. It is because it has a few superficial similarities that it caught my attention.
 
My reason for me being so much in support of equal-loudness in headphones is I have observed far too many issues with headphones under normal listening scenarios that follow diffuse equalization closely. With the HD 700 and others, however, I do not encounter these problems as much. This leads me to believe that when an added boost in the treble and bass in the vein of equal-loudless curves is applied, the sound is more pleasing and most desireable. I see this correlation in the HiFiMAN HE-1000, the Sennheiser HD 700, the Sennheiser HD 800, the Beyerdynamic T1, and several other popular models, and it makes sense.
 
For now, I am happily waiting to see what the next decade of headphone research and development will take us to with regards to this. There is still much that can be done to improve sound reproduction for headphones, and this is just scratching the surface. I still stand by my statement that a combination of diffuse field equalization with an intermediate level equal-loudness curve is optimal. With the next wave of high-end headphones that will be released over this period of time, I look forward to, hopefully, seeing my hypothesis verified in their design execution.

 

[tf10charged]

still thinking about whether to get a matrix hpa-1 for hd700.
 
a good buy for $170? warmish sound? 
 
Quote:

as you can see, I've got that end covered as well. Better results with the tube amps. Tube amps. In my experience seem to tame treble so it's not fatiguing. But my violectric ss amp does very well with all of them. Also have a cheap matrix m-stage that sounds pretty darn good.

 

[tf10charged]

  Yes, it is a hypothesis, albeit well-researched, a hypothesis that will take time to be proved or disproved. If we did not take correlations out into the open and have them publicly scrutinized as we are doing now, underlying causation could never be identified or understood. Yet we need to seriously consider them, with adherents and detractors on both sides to tear the cases apart, so as to come to a final conclusion. Fortunately, this is no problem, or we would not be having this conversation to begin with.  
 
Now, I do not claim the Harman Target Response Curve is perfect, and I admit a bit of undue, inaccurate hyperbole in my claims. I should have more accurately stated that it is a step in the right direction, a direction Tyll puts a lot of stock in as well. Granted, there are quite a few issues people outside of Harman's testing are having when using the curve, such as underrepresented bass, so it is not without its quibbles. It is because it has a few superficial similarities that it caught my attention.
 
My reason for me being so much in support of equal-loudness in headphones is I have observed far too many issues with headphones under normal listening scenarios that follow diffuse equalization closely. With the HD 700 and others, however, I do not encounter these problems as much. This leads me to believe that when an added boost in the treble and bass in the vein of equal-loudless curves is applied, the sound is more pleasing and most desireable. I see this correlation in the HiFiMAN HE-1000, the Sennheiser HD 700, the Sennheiser HD 800, the Beyerdynamic T1, and several other popular models, and it makes sense.
 
For now, I am happily waiting to see what the next decade of headphone research and development will take us to with regards to this. There is still much that can be done to improve sound reproduction for headphones, and this is just scratching the surface. I still stand by my statement that a combination of diffuse field equalization with an intermediate level equal-loudness curve is optimal. With the next wave of high-end headphones that will be released over this period of time, I look forward to, hopefully, seeing my hypothesis verified in their design execution.

saw that tyll starts to talk about the harman curve. now we finally know why HD700 sounds so different than 600/650   they trying to match the harman curve eh. 
 
now we can see how confident the germans are, they dont even bother to talk much about why hd700 sounds like that after 3 years now we know.

 

[raybone0566]

Yes, matrix is a good sounding amplifier.

 

[samandhi]

  I don't pay attention to curves at all, I listen, and if I like, I buy it. Pretty simple science to me hehe.

 

[Mechans1]

The classic Latin style rice and beans recipe uincludes a mirapiox of celery onions garlic and other aromatic cooked until translucent.  Add the one can of beens with most of the surrouinding fluid drained away from the beens.  Cook an appropriate quanity of rice until done according to your recipe.  Mix the rice and beans together, add a healthy amount of the Sofrito essentially a flavored mild tasting tomato concentrate, stir very well, , heat the whole business in the microwave for about 90 sec. adjust the salt and use a red hot type pepper sauce to give it some heat.  Stir and serve immediately with your protein elements. 
P.S.It is delicious and nutritious.
PPS I had to cook on my own time as well

 

[dazzerfong]

  Yes, it is a hypothesis, albeit well-researched, a hypothesis that will take time to be proved or disproved. If we did not take correlations out into the open and have them publicly scrutinized as we are doing now, underlying causation could never be identified or understood. Yet we need to seriously consider them, with adherents and detractors on both sides to tear the cases apart, so as to come to a final conclusion. Fortunately, this is no problem, or we would not be having this conversation to begin with.  
 
Now, I do not claim the Harman Target Response Curve is perfect, and I admit a bit of undue, inaccurate hyperbole in my claims. I should have more accurately stated that it is a step in the right direction, a direction Tyll puts a lot of stock in as well. Granted, there are quite a few issues people outside of Harman's testing are having when using the curve, such as underrepresented bass, so it is not without its quibbles. It is because it has a few superficial similarities that it caught my attention.
 
My reason for me being so much in support of equal-loudness in headphones is I have observed far too many issues with headphones under normal listening scenarios that follow diffuse equalization closely. With the HD 700 and others, however, I do not encounter these problems as much. This leads me to believe that when an added boost in the treble and bass in the vein of equal-loudless curves is applied, the sound is more pleasing and most desireable. I see this correlation in the HiFiMAN HE-1000, the Sennheiser HD 700, the Sennheiser HD 800, the Beyerdynamic T1, and several other popular models, and it makes sense.
 
For now, I am happily waiting to see what the next decade of headphone research and development will take us to with regards to this. There is still much that can be done to improve sound reproduction for headphones, and this is just scratching the surface. I still stand by my statement that a combination of diffuse field equalization with an intermediate level equal-loudness curve is optimal. With the next wave of high-end headphones that will be released over this period of time, I look forward to, hopefully, seeing my hypothesis verified in their design execution.

Fair enough mate. The effect you're observing is actually your own head responding to lower volumes: the headphone itself wouldn't change frequency response (or at least it shouldn't) when you lower its volume. However, personally, I'm more interested in the 'magic' of soundstage: we can EQ the tone response to death, but you can barely change the soundstage.

 

[Hifihedgehog]

  Fair enough mate. The effect you're observing is actually your own head responding to lower volumes: the headphone itself wouldn't change frequency response (or at least it shouldn't) when you lower its volume. However, personally, I'm more interested in the 'magic' of soundstage: we can EQ the tone response to death, but you can barely change the soundstage.

I do prefer the things it brings to table for lower volume listening. It is downright unsafe to listen over 80 decibels for extended periods. The frequency curve with its slight smile I think helps sound elements fall right into place at those volumes.
 
There is something very unique to angled drivers that gives a heightened sense of immersion. I think it has something to do with the way the soundwaves are absorbed and deflected by the outer ear. For me, I compare it to looking at an LCD screen head-on versus slightly over to the side. Off-axis, you lose contrast and inner detail and things start to look distorted. Head-on, the soundstage gains depth, proportions are natural and the details emerge. In a way, angled drivers in headphones are like being in the sweet spot of speakers. In headphones like the Sennheiser HD 6x0 that have non-angled drivers, I notice those problems. In the HD 700, the soundstage just "clicks." It would be cool to see what is going on in the wave propagation by comparing traditional headphones against those with angled drivers.

 

[dazzerfong]

I do prefer the things it brings to table for lower volume listening. It is downright unsafe to listen over 80 decibels for extended periods. The frequency curve with its slight smile I think helps sound elements fall right into place at those volumes.

There is something very unique to angled drivers that gives a heightened sense of immersion. I think it has something to do with the way the soundwaves are absorbed and deflected by the outer ear. For me, I compare it to looking at an LCD screen head-on versus slightly over to the side. Off-axis, you lose contrast and inner detail and things start to look distorted. Head-on, the soundstage gains depth, proportions are natural and the details emerge. In a way, angled drivers in headphones are like being in the sweet spot of speakers. In headphones like the Sennheiser HD 6x0 that have non-angled drivers, I notice those problems. In the HD 700, the soundstage just "clicks." It would be cool to see what is going on in the wave propagation by comparing traditional headphones against those with angled drivers.

I've only had one other angled driver headphone (MDR-1A) and it's sounstage wasn't bad either. The more interesting question may be, why it does do that.

 

[Hifihedgehog]

I've only had one other angled driver headphone (MDR-1A) and it's sounstage wasn't bad either. The more interesting question may be, why it does do that.

Yeah, I wish I knew as well. The quickest thing to see is that something in the time domain will change. I remember reading an article where it explained something about this. All sound travels at the same speed but at certain wavelengths it enters the ear more quickly due to how long the sound wave is. Something else to look at is the quality of the sound waves. When the sound hits the outer ear in parallel to it instead of indirectly, there may be better chaneling of the sound into the ear. This may mean reduced distortion of individual sound waves. Those are just some educated guesses I have which may explain why angled drivers sound better. I think there is a very good reason why all of the latest flagship headphones have angled drivers.