CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS

Lobby => Headphone Measurements => Topic started by: wnmnkh on August 11, 2015, 02:23:31 AM

Title: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: wnmnkh on August 11, 2015, 02:23:31 AM
http://personal.audioquest.com/nighthawk-measurements

Basically, folks at AudioQuest does not use DF nor FF, using their own. Here is one of the reasons.

Quote (selected)
Because their application is based on the incorrect assumption that the listener’s head and ears are always bypassed when listening to audio through headphones, they introduce some spectral colorations that cannot be compensated for by the brain; this results in mid and high-frequency emphasis.

I can't help myself but agree to it. Headphone is not a IEM, and the soundwave indeed travels thru ear structures.

That said, I think folks at AudioQuest understand well; for most people who are supposed to be used to bright-sounding headphones would feel Nighthawk muddy and low-resolution at short audition during shows and meets. I think Nighthawk probably needs some brain-adjustment time.

Well, soon or later I will find out myself with my own equipment... I was actually unaware of the fact that Nighthawk was been released to venders.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: OJneg on August 11, 2015, 02:48:20 AM
Yeah, we should hit up some local dealer and see if they have them.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Anaxilus on August 11, 2015, 02:52:27 AM
I can't help myself but agree to it. Headphone is not a IEM, and the soundwave indeed travels thru ear structures.

That said, I think folks at AudioQuest understand well; for most people who are supposed to be used to bright-sounding headphones would feel Nighthawk muddy and low-resolution at short audition during shows and meets. I think Nighthawk probably needs some brain-adjustment time.

I'm going to come off a little strong here (as usual), but rest assured I'm only addressing this commonly espoused belief directly and not making a personal comment. That said, I couldn't disagree more. Playing real life musical instruments requires ZERO brain-adjustment/psychoacoustics to understand their sound. They too pass through 'ear structures'. If it sounds muddy or low resolution, it's just wrong period. Real instruments do NOT sound muddy or low resolution.

Making an objective claim about what the proper and accurate frequency response of a headphone should be, and then falling back on the subjectivity of letting your brain burn-in is just a bunch of crap.

Having said that, precise diffuse field tuning for a headphone does sound bright and inaccurate up top. Both are wrong to different extents.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: wnmnkh on August 11, 2015, 03:30:17 AM
I'm going to come off a little strong here (as usual), but rest assured I'm only addressing this commonly espoused belief directly and not making a personal comment. That said, I couldn't disagree more. Playing real life musical instruments requires ZERO brain-adjustment/psychoacoustics to understand their sound. They too pass through 'ear structures'. If it sounds muddy or low resolution, it's just wrong period. Real instruments do NOT sound muddy or low resolution.

Making an objective claim about what the proper and accurate frequency response of a headphone should be, and then falling back on the subjectivity of letting your brain burn-in is just a bunch of crap.

Having said that, precise diffuse field tuning for a headphone does sound bright and inaccurate up top. Both are wrong to different extents.


Well, "muddy or low resolution" is not what I perceived when I was listening to these headphones. From CES to near-production model I've heard at a recent meet have been consistent: a little bit warm but otherwise very neutral. However, a lot of people say such terms describing the headphones.

The reason why I said 'brain-adjustment' is that, despite what you said, very few people actually listen to real life musical instruments these days, thus used to electronically amplified sound. Pretty much 90% of music they listen to is electronically amplified. To many people, their most expensive headphones (it can be HD700 or K812... you get the idea) are usually their 'reference' sound.

If people are getting used to harsh sound... the brain will eventually make 'adjustment' on that sound. For instance, if I was listening to my unmodded HD800 for a long period of time, and suddenly I change to HD650, I usually feel HD650 dark and muddy for first 10~30 minutes until my brain re-adjust itself.

The ideal solution would be listening to real-life performance first then listen to same performance via headphones, but we all know that's near impossible.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Bill-p on August 11, 2015, 05:06:54 AM
I would have to agree with Anax here. It's one thing to say "we have a target response that we think will subjectively fit most folks", and it's another when one claims "we have a target response that is more right than everything else that's being used, and if you think our target is false, your brain needs adjustments".

On that note, I haven't heard new Nighthawk, but what I heard last time was like... "Eh?"

If it is to be neutral to me, it needs to get brighter up top. And some here knows my preference typically goes for something like the LCD-2. In fact, I find the LCD-2r2 kinda grating and grainy in the treble.

There is such a thing as a headphone that's smooth, slightly dark, and super clean/clear that is not a Stax. I think this is what AudioQuest is gunning for. I need to hear the new version (if there is one?) to judge, but I don't think their target is right.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: x838nwy on August 11, 2015, 05:24:46 AM
So basically, they designed a pair of headphones based on their own goals and methods. An okay approach, I guess, but i don't get the brain-readjust thing. Does this mean if I don't like them my brain hasn't adjust correctly?
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Marvey on August 11, 2015, 05:43:57 AM
Trained ears > measurements based on blah blah blah blah blah blah blah blah blah science.



Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: wnmnkh on August 11, 2015, 05:44:28 AM
I would have to agree with Anax here. It's one thing to say "we have a target response that we think will subjectively fit most folks", and it's another when one claims "we have a target response that is more right than everything else that's being used, and if you think our target is false, your brain needs adjustments".

On that note, I haven't heard new Nighthawk, but what I heard last time was like... "Eh?"

If it is to be neutral to me, it needs to get brighter up top. And some here knows my preference typically goes for something like the LCD-2. In fact, I find the LCD-2r2 kinda grating and grainy in the treble.

There is such a thing as a headphone that's smooth, slightly dark, and super clean/clear that is not a Stax. I think this is what AudioQuest is gunning for. I need to hear the new version (if there is one?) to judge, but I don't think their target is right.

So basically, they designed a pair of headphones based on their own goals and methods. An okay approach, I guess, but i don't get the brain-readjust thing. Does this mean if I don't like them my brain hasn't adjust correctly?

I have to admit this brain adjustment is still rather uncertain subject. One thing sure is that brain does a lot of calculations to make a sound collected by ears "right" (it does not mean the final signal we feel is accurate.) But as far as I know, not much is known.

My uneducated guess is that some people would prefer and adjust quickly to certain colorations of the sound (hence some people do like high-end Ultrasone, for example) while others may never be able to (I never could 'adjust' to the sound of Sony SA5000 even after long period of listening, eventually returned back to the vender, for example.)

Brain does a lot of the adjustments, that's for sure. It is theorized that one of the reasons why tinnitus occurs is this adjusting behavior of the brain. For instance, if a person loses an ability to hear a certain frequency of the sound due to hearing loss, the brain tries to compensate the loss by perceiving other nearby frequencies in amplified manner, causing pain.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 11, 2015, 05:45:23 AM
I wonder what 'flagship' headphone they used to compare the NH to ?
Or did they use the 'average' of a few flagships ?
Never seen any flagships measure like that.

I agree that setting a 'new' target response is a bit fishy and also think MOST pop recordings suffer from 'conditioned' guys at the mixing table + their monitors and thereby creating colored sound to begin with.
Sure there are some engineers with excellent ears + gears but I seriously wonder about most of them.
I am quite sure most recordings sound excellent in the studio they made the final mix in at blasting SPL's.

Olive Welti and Tyll also created new target responses... I wonder how many will follow.
I do think DF and FF are both incorrect as well.

Well made recordings, without too many 'adjustments' SHOULD sound 'real' on a good headphone and if that makes lesser recordings sound crap so be it.
That (real sounding music) is what should determine the target response IMO not what a recording sounds like in 'a room' with speakers nor what (averaged) type of headphones sound 'most right' to a large group of people.


Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: wnmnkh on August 11, 2015, 06:07:15 AM
Trained ears > measurements based on blah blah blah blah blah blah blah blah blah science.

Sure, but we still do need 'reference' that everyone should follow.

I wonder what 'flagship' headphone they used to compare the NH to ?
Or did they use the 'average' of a few flagships ?
Never seen any flagships measure like that.

I agree that setting a 'new' target response is a bit fishy and also think MOST pop recordings suffer from 'conditioned' guys at the mixing table + their monitors and thereby creating colored sound to begin with.
Sure there are some engineers with excellent ears + gears but I seriously wonder about most of them.
I am quite sure most recordings sound excellent in the studio they made the final mix in at blasting SPL's.

Olive Welti and Tyll also created new target responses... I wonder how many will follow.
I do think DF and FF are both incorrect as well.

Well made recordings, without too many 'adjustments' SHOULD sound 'real' on a good headphone and if that makes lesser recordings sound crap so be it.
That (real sounding music) is what should determine the target response IMO not what a recording sounds like in 'a room' with speakers nor what (averaged) type of headphones sound 'most right' to a large group of people.


I believe it's Beyer T1. Yeah, not exactly 'flagship' headphone.
I don't think they used subjective listening to create their target response. From what I've read, it's pretty much created by calculations based on measurements (such as effects of human torso, absorption, etc)

Well, about 'real sounding music' part... It's really hard to define 'real sounding music' because it is not just instruments and/or human voices that determine the sound.... The environment takes a huge role on how sound is produced. I mean, it's obvious that sound signature of a large orchestra hall is quite different from that of a small, enclosed room or inside of a church. Real sound music should be reference, but in reality it is also completely impossible at the same time.

Harman Kardon uses the sound signature of their reference listening room to create their Olive Headphone target, while others use non-resonant chambers.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: OJneg on August 11, 2015, 07:15:50 AM
I believe it's Beyer T1.

Well even the T1 doesn't sound like that. We are talking perceptual FR here.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 11, 2015, 07:19:15 AM
Well, about 'real sounding music' part... It's really hard to define 'real sounding music' because it is not just instruments and/or human voices that determine the sound.... The environment takes a huge role on how sound is produced. I mean, it's obvious that sound signature of a large orchestra hall is quite different from that of a small, enclosed room or inside of a church. Real sound music should be reference, but in reality it is also completely impossible at the same time.

Indeed, and then there is also something like how a recording was mic'ed.
How loud the SPL is during an evaluation obviously also has a great impact in how 'neutral' a HP is perceived.


Sure, all instruments sound quite different in different 'rooms' and/or outside.
Yet, in all these circumstances we can pick out the 'real' sound of the instruments which, I think, has to do with the first wavefront that our brain finds most interesting for determining 'what' it is we are hearing and where it originates from (localization).
Amongst it by comparing incoming sounds to our own (perhaps often misguided) reference of how something should sound.
 
The (later arriving) reflections tells us something about room dimensions/conditions.
When you measure the FR of the first wavefront and add room resonances + reflections the total SPL is not 'flat' in FR while the source could be.
Yet, the 'sonic signature' of the sounds that arrive first may well determine how 'real' something sounds and coloration is perceived as 'surrounding' and not necesarilly as a coloration of the source.

A well made recording in those different recording circumstances should still sound 'real' and the reflections should still be perceived as an image of the conditions/surrounding it was made in. At least it does to me on better headphones.
The 'speaker in a room emulating' headphones don't seem to do it for me (too dark) but may well be a 'reference' to the armchair music appreciaters.

Of course 'training' with real (unamplified) music remains essential if you want your built-in reference in your head to work better in an absolute way.

I think the brain calibrates itself continuously though.
When I start listening to a KSC75 it sounds quite 'real' to me after a very short time already.
Yet, when I listen to a better headphone or real music first the flaws of the KSC75 are immediatly appearant and it takes a LOT longer for me to 'believe' the KSC again.

remains an interesting topic... what the reference should be and how to determine it.

In the end I am convinced it is really all moot and think that what's one man's reference is another mans nightmare.
Everyone should determine for themselves what sounds good to THEM, not what someone else feels is 'correct'.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: OJneg on August 11, 2015, 07:24:36 AM
In the end I am convinced it is really all moot

That explains the nature of your long-winded and circular posts  :)p8
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Anaxilus on August 11, 2015, 07:26:47 AM
Well, about 'real sounding music' part... It's really hard to define 'real sounding music' because it is not just instruments and/or human voices that determine the sound.... The environment takes a huge role on how sound is produced. I mean, it's obvious that sound signature of a large orchestra hall is quite different from that of a small, enclosed room or inside of a church. Real sound music should be reference, but in reality it is also completely impossible at the same time.

Not really. In most cases instruments are mic'd at the source so there is very little environmental concern, at least in how you are describing it. Acoustic treatments are usually done to prevent the environment from interacting with a recording rather than trying to capture the ambiance of a specific venue and chasing each others tails. Granted, there are recordings and live performances where that is part of the equation (hearing specific reflections and ambient cues), but they are the exception and not the rule. So they shouldn't play a part in chasing reference gear or masters unless you know those particular colorations intimately and can compensate. That's actually true of any recording as 99.989% of recordings have something off about them somewhere, it's simply a matter of degrees.

Point is, for reference, audio engineers would do what they can to remove the environment from the equation. As you hear better gear (sources, mics, etc.) and better mastering, you realize just how good and transparent quality recordings can be. As a result, I feel totally confident when listening to gear that I can pretty much tell exactly where in the chain something is off without having to confuse myself chasing sonic phantoms. We actually had an interesting incident of just that when performing some ADC rips a week ago. Having enough experience with our gear, we could use deduction and pinpoint the source of a specific issue we were hearing in the recordings.

I suppose what I'm saying is, it's a lot easier to achieve a reliable level of accuracy even if it may be very difficult to achieve extreme precision. So don't worry about being precise, worry about being accurate.

I think this is similar to what solderdude was getting at. Sorry, I was typing too slowly while watching Scarface.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Anaxilus on August 11, 2015, 07:42:56 AM
I think the brain calibrates itself continuously though.
When I start listening to a KSC75 it sounds quite 'real' to me after a very short time already.
Yet, when I listen to a better headphone or real music first the flaws of the KSC75 are immediatly appearant and it takes a LOT longer for me to 'believe' the KSC again.

remains an interesting topic... what the reference should be and how to determine it.

Correct. I've talked with Tyll about this a few times. Psycho-acoustic adjustment is a survival reflex. Hearing is designed to keep us alive and functioning efficiently. The brain/ear relationship adjusts in ways to maximize your efficiency by removing distractions (treble glare, grain, etch, booming pounding bass, dry scratchy vocals, etc.) that would otherwise distract your brain. This is why I've become accustomed to listening to gear and phones using a regimen that takes no longer than 10-30 secs depending on the case and what I'm trying to achieve. Once you settle in and let yourself adapt, your reference is toast and you have to start over, essentially cleansing your aural palate. Only time and quiet can do that.

So how to determine reference? Well, I like to go off just normal daily ambient conditions just as you would attending a live performance or playing an instrument. Unless you work with jackhammers or on a tarmac with Boeing 747s, your ears are largely set for day to day activities in my estimation. So it's okay to start there IMO.  I should be able to just walk over and put on a set of phones or speakers and be transported to the music room where it was recorded immediately.

Granted early in the morning versus later in the afternoon might see a normal rise in SPL compensation, but tone and timbre would remain relatively consistent within Fletcher Munson and the fundamental SPL level at which live instruments are performed is relatively consistent as well. Now some prefer to listen a lot lower for various reasons and preferences too. At that point, different gear could very well provide more accurate sound at those levels than say gear that would perform better at higher SPLs. To me, SPL is the only place where there is a very real audible sliding scale happening. Personal references and listening conditions are very rarely mentioned in audio reviews, yet are some of the most crucial.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 11, 2015, 07:49:22 AM
So how to determine reference? Well, I like to go off just normal daily ambient conditions just as you would attending a live performance or playing an instrument. Unless you work with jackhammers or on a tarmac with boeing 747s, your ears are largely set for day to day activities in my estimation. So it's okay to start there. Granted early in the morning versus later in the afternoon might see a normal rise in SPL compensation, but tone and timbre would remain relatively consistent within Fletcher Munson and the fundamental level at which live instruments are performed is relatively consistent as well. Now some prefer to listen a lot lower for various reasons and preferences too. At that point, different gear could very well provide more accurate sound at those levels than say gear that would perform better at higher SPLs. To me, SPL is the only place where there is a very real audible sliding scale happening. Personal references and listening conditions are very rarely mentioned in audio reviews, yet are some of the most crucial.

Yup.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Marvey on August 11, 2015, 03:55:07 PM
I trust OJ's or Luis' ears > science
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: drfindley on August 11, 2015, 05:26:26 PM
I'm just excited for the day that science catches up to Luis' or OJ's ears.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Priidik on August 11, 2015, 07:58:06 PM
Having said that, precise diffuse field tuning for a headphone does sound bright and inaccurate up top. Both are wrong to different extents.

Fucking EarTweeter is still the most accurate hp i have heard to reproduce real acoustic instruments, much more so in moded form, that's true.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Marvey on August 11, 2015, 08:08:40 PM
I'm just excited for the day that science catches up to Luis' or OJ's ears.

Already has to a large extent. It's called Changstar and why we don't worry about HRTF, diffuse-field, free-field, reality-distortion-fields, Sada-Flores-Chen no-compensation, or whatever other science blah blah blah that over-thinks or over-analyzes things that don't need to be over analyzed. 90% of the people who talk about this stuff really have no clue what they are talking about.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: madaboutaudio on August 12, 2015, 12:07:33 AM
Maybe Skylar is using ESS Sabre(Oppo HA1?) as his reference dac?  :spank: That could explain for the duller sound?
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: madaboutaudio on August 12, 2015, 12:16:35 AM
Quote (selected)
We recommend that listeners put up to 150 hours of active playing time on NightHawk headphones before making serious attempts at assessing its sound quality.

I must say with my previous experience with Vsonic GR07(Biocellulose Diaphragm) IEM.

It took a damn long time(hundreds of hours) for the driver to break-in/burn-in(before that it was pretty dull and slow)
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: anetode on August 12, 2015, 01:54:16 AM
This is the same sort of bullshit thinking that led the Ultrasone "scientist" to add random treble peaks to his headphones. Going against DF or FF is fine, but claiming to have some sort of revolutionary realization hitherto undiscovered by any audiologist or engineer requires either research or an actually good sounding headphone to back up the claim. Then again, this is fucking AudioQuest, king of the cable bullshit companies we're talking about.

edit: OK, after having read through all of the whitepaper, they make a few assumptions about HRTF and target response which go against both listener preference studies as well as measurement surveys which correct for the various factors they've discussed. Instead the designer appears to have followed their own conclusions based on a few questionable measurement corrections without the necessary listening tests or third party verification of the measurement effects. Simply put, the frequency response tuning is wrong even if the headphone is otherwise sound.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: OJneg on August 12, 2015, 02:13:46 AM
This is the same sort of bullshit thinking that led the Ultrasone "scientist" to add random treble peaks to his headphones. Going against DF or FF is fine, but claiming to have some sort of revolutionary realization hitherto undiscovered by any audiologist or engineer requires either research or an actually good sounding headphone to back up the claim. Then again, this is fucking AudioQuest, king of the cable bullshit companies we're talking about.

What specifically about the Nighthawk's target curve doesn't make sense? At least on the surface it's following a logical pathway. I'd like to see Ultrasone provide a similar writeup to explain their S-Logic.

I fail to see how bringing up the fact that Audioquest sells expensive cables as relevant to the discussion. It's just a distraction that leads to the objectivist ad hominem dismissal of what might be valid method of tuning headphones.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: anetode on August 12, 2015, 02:25:19 AM
What specifically about the Nighthawk's target curve doesn't make sense? At least on the surface it's following a logical pathway. I'd like to see Ultrasone provide a similar writeup to explain their S-Logic.

They do not adequately test their hypothesis (target curve) by testing it either against prior measurement surveys or by running their own listening preference panels. Their assumptions appear to be logical, but that isn't enough to make something either practical or true in the real world. Without controlled testing they've come up with nothing more than a hypothesis (and one with which my ears disagree, for all of the anecdotal small sample size evidence that's worth).

Ultrasone's Dr. Germansoundingname did publish a few papers, though the last time I tried to find them at their website it appeared that some were taken down. But at least he went through the trouble of measuring real people rather than arguing against strawman dummy heads.

I fail to see how bringing up the fact that Audioquest sells expensive cables as relevant to the discussion. It's just a distraction that leads to the objectivist ad hominem dismissal of what might be valid method of tuning headphones.

Might be but isn't. To be clear, I am not going to dismiss the Nighthawk's designer because of his company affiliation, but the fact that his company is based on selling bullshit is going to make me a hell of a lot more skeptical of the product's scientific claims. That is to say that if one were to find a paper on chemistry in a homeopathy journal, a cynical approach is warranted regardless of the implied ad hominem.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Marvey on August 12, 2015, 02:26:22 AM
Sounds too warm last time I heard it. High bass bleeding into mids. Don't need science to figure that out. You heard it like that too OJ. You know their target curve and science behind it is fucked up. You know this because I know you've made two or three speakers now... with measurement aids.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: OJneg on August 12, 2015, 02:35:34 AM
They do not adequately test their hypothesis (target curve) by testing it either against prior measurement surveys or by running their own listening preference panels. Their assumptions appear to be logical, but that isn't enough to make something either practical or true in the real world. Without controlled testing they've come up with nothing more than a hypothesis (and one with which my ears disagree, for all of the anecdotal small sample size evidence that's worth).

Listener preference panels give you Olive-Welti curves which sounds like absolute shit for headphones. I'll go back to the point that Marv is harping on...good ears beats the opinions of the plebs every time.

Yes, it all is just a hypothesis but what specific aspects of the hypothesis do you find to be fallacious? Which parts wouldn't stand up under further investigation? Genuinely curious as that's what this thread should be looking at.

Sounds too warm last time I heard it. High bass bleeding into mids.

Yes I agree. Too much upper bass last time I heard it, but now I'm wondering if the biocellulous driver needed more burn in time or whatever.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: OJneg on August 12, 2015, 02:45:51 AM
Which parts wouldn't stand up under further investigation?

I for one am skeptical about the the "absorption effect" one which causes a 6dB dip at around 1.4k. Seems like it would make the transition in the upper mids less natural. If things were smoother in that region it might make that upper bass accentuation less bothersome
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Tyll Hertsens on August 12, 2015, 04:17:11 PM
Listener preference panels give you Olive-Welti curves which sounds like absolute shit for headphones.


Really!? Care to elaborate?
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Marvey on August 12, 2015, 05:46:00 PM
Slightly off-topic, and someone please correct me if I am wrong:

The Olive-Welti curve is response target only to be applied to a dummy head fitted with a calibrated measurement ear, specifically a GRAS 43AG coupler. It's my understanding that all bets are off if the target curve is used on a different measurement apparatus. I thought this was worth saying for the 50th time because there seems to be a lot of confusion or misunderstanding, especially among the armchair headphone scientists, of what the Olive-Welti response target actually is.

Now as far as what the OW curve was referenced to (it's also my understanding that calibrated speakers at Harmon were used as the reference), I have no idea what the frequency response of those calibrated speakers were at the listening position. I've stated before, and I believe that OJ also agrees, that the B&K curve, as described in a AES paper from the 1970s, is a good target for speakers when measured at the listening position. Many studio professionals tend to agree, although steepness of the downward slope does tend to differ among individuals.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: OJneg on August 12, 2015, 05:46:44 PM
Push up bass, reduce stuff at 2k. Based on what I've played around with EQ it's not natural sounding to me.

(https://diyaudioheaven.files.wordpress.com/2014/03/correction-plots.png)

I suppose it's not too different looking from the Nighthawk's curve on second thought.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 12, 2015, 06:29:53 PM
Does anyone like Harman headphones to begin with ?
I listened to most of the JBL line and did not care much for the sound of any of them.
I suppose their headphones are marketted with that 'target curve' in mind (at least the expensive ones) why else would one do all this research and not apply it.

While it is true that the OW correction curve can only be applied to the same test setup Harman has (the same as Tyll's I believe) the RESULT is a target curve which also is NOT a flat response but like the red curve I drew in the picture OJ posted.
It is close to an the B&K room curve except that it has a dip in the same spot as many headphones have (around 2-3kHz) and a peak around 7kHz which also may headphones show.
So in the end the OW TARGET is a sloping curve with a 'brighter' wide hump around 7kHz.

Also a matter of taste ... many people like HP's EQ'ed or designed to be closer to the FR of a room, I don't.
Average people do tend to like bassier headphones with somewhat subdued treble for obvious reasons.

It may al be a matter of experience and 'internal' reference as touched by Anax a while back in this thread.

Have played a lot with EQ myself as well and although some crappy pop recordings do sound 'better' when reproduced via an 'in room curve, I think well made recordings sound too darkish and muddy when played though a 'room' corrected intrinsicly flat headphone and sound much more real on an EQ'ed 'flat' headphone with just a mild (sub) bass boost a bit like the GE target.

Personal opinion/taste though.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Marvey on August 12, 2015, 06:37:33 PM
I suppose it's not too different looking from the Nighthawk's curve on second thought.

That depends. How similar is their measurement apparatus to Sean Olive's?

Where did you get that graph? I want to ascertain if that is indeed how the O-W target translates to speakers @ listening position.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 12, 2015, 06:48:27 PM
The graph was made by me on a not too scientific basis mostly inspired by measurements Rin and Tyll made.

The plot makes sense to me as the OW target headphone was determined by a 'flat speaker' in a Harman test room which is likely to be close to the B&K room curve.
Also the HATS effect as described by AQ has some merits IF you want to emulate a speaker in a 'normal' room at a 'normal distance and position' to a listener.
That curve will be between DF and FF.

Of course if you have a more accurate OW target curve (which I am sure SO will have published somewhere) than a linky please.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Marvey on August 12, 2015, 06:50:17 PM
Does anyone like Harman headphones to begin with ?
I listened to most of the JBL line and did not care much for the sound of any of them.

I suppose their headphones are marketted with that 'target curve' in mind (at least the expensive ones) why else would one do all this research and not apply it.

No Harmon doesn't make headphones according to how their research scientists like them. Harmon shoves people like Olive into the "idiot room" and plays that card when handy "we have really smart people working for us". However, when it comes time for making headphones, the marketing sales guys idiots always win. People like Olive are too dangerous in multi-layered and vertically segment corporate environments. Even then regarding marketing and sales, AKG sucks at that. They need to hire Tyga and Kylie to market the headphones for them.

It is close to an the B&K room curve except that it has a dip in the same spot as many headphones have (around 2-3kHz) and a peak around 7kHz which also may headphones show.

If and only if the red curve is actually correct, I don't think the in-room translation of the O-W target is close to the B&K curve at all. The downward slope begins at 50Hz and is down 5db at 2kHz. That's way too sudden and way too steep.

Quote (selected)
Also a matter of taste ... many people like HP's EQ'ed or designed to be closer to the FR of a room, I don't.

Can you elaborate on this? I don't quite understand "FR of a room". What specific targets, room sizes, and measurement distances and angles are we talking about? I think you would be shocked how much my or OJ's speaker tunings or well setup speakers in good studios sound more like HD600s than LCD2s. Keep in mind that the slight rolloff of the B&K target (that I use) at listening positioning usually equates to flat when speakers are measured head-on at 0 degree axis.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Marvey on August 12, 2015, 06:54:41 PM
Also the HATS effect as described by AQ has some merits IF you want to emulate a speaker in a 'normal' room at a 'normal distance and position' to a listener.
That curve will be between DF and FF.

How do you define a  'normal' room at a 'normal distance and position' to a listener? The Nighthawk certainly doesn't sound like that to me. It sounds like a speaker that is overly bassly and warm. No speaker I heard at THE SHOW for the last several years sounded like that except maybe the Sonus Faber Stradavari. The Nighthawk is actually worse because the bump bleeds more into the lower mids.


(http://cdn.stereophile.com/images/archivesart/SFSfig3.jpg)

Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 12, 2015, 07:04:07 PM
If and only if the red curve is actually correct, I don't think the in-room translation of the O-W target is close to the B&K curve at all. The downward slope begins at 50Hz and is down 5db at 2kHz. That's way too sudden and way too steep.

Like I mentioned, its not what you believe to be true that counts.
My plot was derived from known plots and the difference to 'known' corrections which are again referenced to 'flat'.
Perhaps you have the real target response from Harman lying around somewhere ?


Can you elaborate on this? I don't quite understand "FR of a room". What specific targets, room sizes, and measurement distances and angles are we talking about? I think you would be shocked how much my speaker tunings or well setup speakers in a studio sound more like HD600s than LCD2s. Keep in mind that the slight rolloff of the B&K target (that I use) at listening positioning usually equates to flat when speakers are measured head-on at 0 degree axis.

I already did, it's somewhere on page 2 or so.

Indeed an 'in room' curve is how speakers on average MEASURE in a very specific room which differs from Harmans room at the listening position.
But to more trained ears it does not sound like that curve at all which was my point.

Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 12, 2015, 07:14:20 PM
How do you define a  'normal' room at a 'normal distance and position' to a listener? The Nighthawk certainly doesn't sound like that to me. It sounds like a speaker that is overly bassly and warm. No speaker I heard at THE SHOW for the last several years sounded like that except maybe the Sonus Faber Stradavari. The Nighthawk is actually worse because the bump bleeds more into the lower mids.

I do not define 'a room' I merely overlayed known (and granted a derived OW) plots.

I totally get your point about rooms and agree completely with you.

Never heard the nighthawk, can't comment on it and didn't.
I can only comment on the 'science' behind it which has some truth in it to most people, just not to me.

Their 'target' is different than the ones in the plot (but has some resemblance in certain bands to the, derived, OW plot.
AQ's 'measured' plot is often 5dB off from their own target anyway which I think is a lot.


B.T.W. their driver looks an awful lot like the Foster driver.
It looks like the TH900 membrane with a slightly different 'basket' and voicecoil slit.
See http://www.freepatentsonline.com/6917690.html (http://www.freepatentsonline.com/6917690.html) it seems someone beet them to it ... or are these the same guys ?
Does someone know if the drivers are made by Foster (acc to specs supplied by AQ)
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: OJneg on August 12, 2015, 07:30:11 PM
Can you elaborate on this? I don't quite understand "FR of a room". What specific targets, room sizes, and measurement distances and angles are we talking about? I think you would be shocked how much my or OJ's speaker tunings or well setup speakers in good studios sound more like HD600s than LCD2s. Keep in mind that the slight rolloff of the B&K target (that I use) at listening positioning usually equates to flat when speakers are measured head-on at 0 degree axis.

Well you know me, I actually prefer to tune speakers based on quasi-anechoic measurements taken one meter away from the baffle. Measuring (or more specifically EQing) at the listening position is too much of a moving target. I figure if I get the thing to be flat, I can remove that variable and then play with positioning and toe-in by ear until it sounds like the classic B&K curve recommends.

I like to think the same idea applies to headphones, in that you can remove all the inner ear and HRTF stuff and just measure the sound coming out of the driver. That response should be relatively smooth and flat. At least in my experience, the best headphones tend to be flat in this scenario. You can do this by using either coupling to some sort of open cell foam with minimal shtuff around it. Or, heck, just sticking a capsule mic close to a driver uncoupled can tell you a lot.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Anaxilus on August 12, 2015, 07:30:33 PM
Think I asked a marketing person back at Canjam south whether they were Fostex. The basic response was it was 'their own' driver. Take that for what it's worth considering the circumstances.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 12, 2015, 07:34:16 PM
I like to think the same idea applies to headphones, in that you can remove all the inner ear and HRTF stuff and just measure the sound coming out of the driver. That response should be relatively smooth and flat. At least in my experience, the best headphones tend to be flat in this scenario.

Yup I agree completely.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: briskly on August 13, 2015, 05:24:42 AM
Olive-Welti curve and summary of headphone research/presentation can be found here. (http://db.tt/XMgixjBP) Response of the adjustments made from flat response at the listening position. I wonder why O-W didn't use a mannequin to determine the response at eardrum-equivalent for the in-room speaker.

O-W rig with headphone use would be generally similar to AQ, but O-W used large hard pinnae in testing, whereas AQ lists three different sets of pinnae used in measurements (hard small, hard and soft large).

Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: wnmnkh on August 13, 2015, 06:27:09 AM
Olive-Welti curve and summary of headphone research/presentation can be found here. (http://db.tt/XMgixjBP) Response of the adjustments made from flat response at the listening position. I wonder why O-W didn't use a mannequin to determine the response at eardrum-equivalent for the in-room speaker.

O-W rig with headphone use would be generally similar to AQ, but O-W used large hard pinnae in testing, whereas AQ lists three different sets of pinnae used in measurements (hard small, hard and soft large).


Yes, this is the presentation file for O-W target, and it is also a great example why trying to make consensus with subjective listening tests, even in ABX, is not really a good idea because of bias caused by preference

If you have noticed, first test with 11 listeners.... 8 of them are Harman employees, who are already very used to Harman's house sound. Of course, it is inevitable that they would prefer the sound that is similar to what they used to hear at their work.

This is how a company can claim "With ABX tests, our speakers come top against competitors! Buy ours!!!" While this can be true, but since the company obviously used its own employees to do ABX, the result is not really valid for general public.

Sure, that test with 219 people are probably more valid, but there are several problems too (Kinda strange there is no result posted for HD518 despite the fact that you can even see it from the pictures they take, huh. Make you think about the result indeed.....)
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Anaxilus on August 13, 2015, 07:17:51 AM
Well whatever. Everyone and their brother spent the last six months telling them they had too much upper bass bleed veiling the mids and not enough air up top. If you don't want to actually listen with your ears, since that's what the you're actually supposed to do with these things, pick whatever curve you want.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: thune on August 13, 2015, 07:27:06 AM
My potential issue with Olive-Welti: it doesn't explore levels in the ear-gain region; it starts with a full ear-gain measurement of an in-room system measured by their GRAS setup (plus some voodoo), which won in a shootout of just 6 response curves. Another paper then explores bass/treble shelf adjustments to this curve. The Olive-Welti curve may be OK compared to the simulations of other headphone responses (using dozens of biquads filters), but it is not the result of a particularly exhaustive search. [OJneg may be right: the O-W curve could drop with a thud in headphonedom.]

And as regards the Nighthawk "white paper": would be funny if they developed a headphone that had all the technicalities right, but had a wrong-headed balance/response-target that drowned it all out.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 13, 2015, 07:56:16 AM
Thanks briskly,

I will redraw my plot when I have some time.
Seems like a combination of the 'standard' room curves + GE targets.

My personal favorite is closer to the GE target (flat with a few dB lift in the lower bass)
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 13, 2015, 08:00:34 AM
And as regards the Nighthawk "white paper": would be funny if they developed a headphone that had all the technicalities right, but had a wrong-headed balance/response-target that drowned it all out.

Nothing some EQ couldn't fix in that case.  :D
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: shotgunshane on August 13, 2015, 11:58:11 AM
Thanks briskly,

I will redraw my plot when I have some time.
Seems like a combination of the 'standard' room curves + GE targets.

My personal favorite is closer to the GE target (flat with a few dB lift in the lower bass)

GE has changed their target A few times over the years. Here is what they currently do: Diffuse Sound Field Equalization + The small room X-Curve Compensation + Bass Compensation

So it seems they are adding in for a room and the 'missing 6db's" do bass perhaps.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 13, 2015, 01:23:30 PM
neither free field nor diffuse field 'corrections' give an accurate compensation curve for headphones.
Both curves compensate for the ear canal + Pinna + room effects but differently because the stimulus is different.
With a headphone the sounds come from the SIDE only and not via a room.
Also the Pinna works differently when sounds come from the sides than when listening to something in front.
So... the only compensation needed for HP's is ear canal + infinite baffle + Pinna but NOT like when coming from the front.
This means that when you 'undo' the room correction (that is enclosed in DF and FF) you end up closer to what a HP 'emits' into your ear canals directly.

Closest way (they figured) was to undo the room by adding compensation for a small room (in which diffuse field is measured) to the DF which sort of 'corrects' the diffuse field compensated signal to become 'flatter' again so they 'undo' some of the room 'acoustics' in essence.
They use this curve to compensate the too high treble response which is caused by reflections:

(http://en.goldenears.net/en/files/attach/images/249/388/a7e4e1735ca195bd1cbe5b7c7f1d5e99.png)

This results in a 'nearer flat' response from 50Hz to 20khz and a too low response (due to the small room not able to do low frequencies) for bass response so they add some extra bass again.
In the earlier plots they showed the rising bass response as a target rather than apply it as compensation to the plot and displaying the result as a 'flat line' where the flat line represents equal perceived (but not measured) FR response.

At least that's what I can deduct from their limited amount of info on this subject.

And then even the X-curve (for theaters = large rooms) is heavily debated over the years... here is some thoughts about it:
http://www.hps4000.com/pages/general/the_mythical_x_curve.pdf (http://www.hps4000.com/pages/general/the_mythical_x_curve.pdf)

That roughly equates to a flat response on a flatbed measurement rig with compensation for bass.
There is a little snag though when using capsules that measure flat to 20Hz in free air.
When these are mounted on an infinite baffle (closed headphone) the bass response also will be elevated in the mic output signal but somewhat differently then just some added subbass.

But this is about how accurate the AQ response is and compared to what 'known reference' and if that target curve is more correct than others.
Then there is the question of how CLOSE the actual headphone is to that curve.
As I saw deviations of over 4dB in various places they aren't close enough (IMO) to their own curve.

From what I saw (would like to see it measured on the CUNT or UB's rig) there is more midbass and less 'clarity' in the NH compared to their own target which certainly seems to be perceived as darker than what 'ideal' sound should sound like.

disclaimer:
Above is all my opinion and not scientific proof nor does it have to be the real truth but is the way I see it.
I can be completely wrong about all this.
Don't really care about compensation curves for HATS as I don't use it.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Marvey on August 13, 2015, 05:17:19 PM
You can buy all the GRAS shit in the world, read all the good AES papers, and use all the coolest European ISO standards. In the end, it won't matter if you don't have good ears. I respect companies that simply make gear and say... this is our sound without trying so hard to prove it's right via marketing science. When the marketing science doesn't gel with good ears, that's makes things even worse. (specs is another matter... good specs are useful)

The DF stuff has always been suspect. DF is arrived at via averaging of signals in time. The initial wavefront, the side reflections, the back wall reflections, the reflections of the reflections, etc. etc. The problem with DF is that the ear doesn't process signals in a defined DCT/FFT window.

In other words, the human ear can to a large extent distinguish the initial signal and filter the reflections. And when it doesn't, like in a huge concert hall with strong long lived reflections, DF compensation isn't like 12db. More like 3db. That's why there's something called the BBC curve. The DF stuff has always been bullshit and more probably than not made up by someone thinking too hard or not thinking enough.

The problem is hobbyist/scientists who have no clue about acoustics, sound engineering, or simply good sound. They read these papers thinking everything is gospel. This DF nonsense should have be called out long ago. Just because some random fuckers wrote a paper shrouded in scientific trappings, graphs, and equations doesn't mean it's right. This even holds true in academia and respected medical journals... Lancet cough cough vaccinations make your kids retarded cough cough. (and yes, there are still enough crazy parents in the neighborhood I live in who refuse to vaccinate their kids)

Scientists should stay the fuck away from audio unless it's to design the most basic building blocks. Good audio is made by engineers (people who actually have to figure out how make the shit work).
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 13, 2015, 07:24:04 PM
updated my plot:

(https://diyaudioheaven.files.wordpress.com/2015/08/correction-plots-2.png)

the OW curve is now based on Harman's plots instead of derived from DF vs OW differences.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Deep Funk on August 13, 2015, 08:30:10 PM
I am a Brüel & Kjaer person.

As long as the midrange is not sucked out or isolated in the audio spectrum I can really enjoy the music. Semi-open and open AKG headphones really did influence my preferences.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 13, 2015, 09:43:32 PM
Strangely enough the B&K curve is the opposite of the AKG sound (talking K500/K501/601/701) with less bass and hotter treble.
In the end you may be an 'inverted' B&K person not a converted B&K person :D

The older HD650 is more like a B&K signature.

The newer K127 and K7xx are closer to the B&K curve, maybe even leaning toward OW.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Deep Funk on August 13, 2015, 10:08:36 PM
Strangely enough the B&K curve is the opposite of the AKG sound (talking K500/K501/601/701) with less bass and hotter treble.
In the end you may be an 'inverted' B&K person not a converted B&K person :D

The older HD650 is more like a B&K signature.

The newer K127 and K7xx are closer to the B&K curve, maybe even leaning toward OW.

I thought the highs needed more decibels. B&K with more highs, I am good...
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Armaegis on August 14, 2015, 04:59:26 AM
(click to show/hide)

I'll admit that fluid dynamics was one of my weaker subjects in aerospace engineering, but I'm pretty sure that you shouldn't be modelling oscillatory pressure waves with a steady state flow. Well, as "steady" as one can assume with turbulent flow since it's a rather complex topic.

I did however enjoy the different use of colours to convey that sense of "danger" with the bright orange, especially with how some of those flow lines passed right through those offending sharp upper corner.

I dunno, this is out of my wheelhouse... but if I were to approach headphone driver and enclosure design from the ground up, I'd look at studying:
- shear and boundary layer effects of small scale openings (100-1000 micron to start), examine primarily changes in "speed" through the boundary layer, measure*/model distortion as a function of transverse layer depth as well as longitudinal distance from the chosen "obstruction"; obviously relate this to depth from driver to ear if possible (*exceedingly difficult at this scale)
- extension of the above, move onto diffusive materials (start with woven textiles, then non-woven/ordered textiles, then foam-type morphology)
- two/three/four chamber Helmholtz systems (looking at atmospheric compliance/impedance from: ear canal to ear-side; ear-side to cup-side; cup-side to atmosphere

Thoughts in my head:
- laminar vs turbulent flow both have "steady states" that can be reasonably predicted; I suspect it's the craptacular transition zone in between that leads to much ugliness in ultra-nearfield sound perception
- maybe this is why almost all my mods involve putting damping materials in front of the driver, as this is a inelegant but "effective" method to minimize variations in flow regimes and equalizes it into a pressure regime
- maybe I'm making this voodoo up
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: speakerphone on August 14, 2015, 05:14:21 AM
updated my plot:

(https://diyaudioheaven.files.wordpress.com/2015/08/correction-plots-2.png)

the OW curve is now based on Harman's plots instead of derived from DF vs OW differences.

In your data, I want to know where the B&K Target is deprived from. Is that a ortho-telephonic gain from B&K company?
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: speakerphone on August 14, 2015, 05:17:02 AM
(http://i.imgur.com/8rZgPoF.png)


data of various compensation targets
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 14, 2015, 06:05:00 AM
In your data, I want to know where the B&K Target is deprived from. Is that a orto-telephonic gain from B&K company?

http://s1217.photobucket.com/user/mitchatola/media/bandk.jpg.html (http://s1217.photobucket.com/user/mitchatola/media/bandk.jpg.html)

http://www.bksv.com/doc/17-197.pdf (http://www.bksv.com/doc/17-197.pdf)

a very, very old B&K plot from a test record.
It is just to show that most target responses have many commonalities but differ just slightly.
Differences do not seem to be more than 3 dB (which is quite audible already)

The compensation plots are more worrying though with differences up to 10dB.
Which one, would you say, is closest to perceived SQ and with what HP/EP ?
You could draw OW in there too (although that may not apply exactly to that specific test fixture)

Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: speakerphone on August 14, 2015, 06:34:28 AM
Huh.. okay. But you can't compare the B&K and O-W target like that, because their tests are not deprived from same DF target.


(http://i.imgur.com/A60ZUV8.jpg)

DF target from B&K company




(http://i.imgur.com/AyLhpmu.png)

DF from O-W study
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 14, 2015, 07:26:37 AM
No you can't compare a compensation curve to a target curve.

A compensation is needed to get to a target curve because the measurement system does not have a linear frequency response.
The O-W correction curve applied to a measurement rig exactly (or very closely) the same as the one O-W use will/should yield the the target curve compared to 'flat' SPL.
In other words (substantially) elevated bass and slightly rolled off treble which is 'preferred' over completely flat SPL or other types of FR response by most people all over the world and ages.
This should sound about the same as a 'flat' speaker in a 'room'.
Some like their headphones to 'sound' similar to this, I have slightly different preferences and am NOT looking to emulate speakers in a 'room' at all but want to hear what the mics picked up.

yeah, some mics are used very close to the instrument and thus should best be reproduced by flat speakers away from you where recordings with mics further from the sound source may best be listened to on flat headphones.
That's where the whole 'room' things often fail... the recordings.

The target (room curves) are 'accumulated' signals at a listening spot (very averaged so VERY different from everyone's listening/living room spaces) where direct sound + reflections are accumulated.
The speaker itself should be 'flat' (presumably at 1m on axis in non reverbant room) in order to get a similar MEASUREMENT.

I capitalize measurement because while it is true that the treble and above all bass response in small rooms alters we can still perceive the speaker ITSELF as 'flat' yet we MEASURE accumulated sounds.
When doing SPL measurements the time component is 'removed' because ONLY the FR is measured and NOT the time.

For this reason alone I feel headphones do NOT have to have a 'room' target response at all but should be flat with a bit of (sub)bass boost to liven it up for several reasons.
Others disagree and Harman (like many others) have shown that most people (trained or not) actually PREFER some bass boost and gently rolled of treble.

All of this has absolutely nothing to do with compensation curves but all with personal preferences AND lets not forget source material.
Not all recordings are 'mixed' using good monitoring setups + there is also something as studio house sounds and preferences of recording personel etc.
All these factors compile to a bunch of very different sounding recordings.
Some of those recordings really NEED bass added and treble reduced to sound 'more real' where recordings where little was being 'altered' a 'flat reproduction' is more 'real' sounding.

So in the end ... its the recording quality that matters most.
For getting out the finest nuances in well made recordings good gear is essential which cannot be 'shown' in a 'room curve' at all.

Best to forget about this all and simply enjoy the music you like on your speakers/headphones if all you care about is sound/reproduction/music/enjoyment.

However, if you like to measure and link what you hear to what you measure.
Want to 'calibrate' the rig or pioneer in HP measurement techniques or just want to apply 'standard' measurement techniques then this is a fun and heavily debated subject.

Measuring is fun for some and perhaps useful, to others it says nothing and may even hate those that do like measurements.

Just my opinion on this.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: speakerphone on August 14, 2015, 08:08:07 AM
The target (room curves) are 'accumulated' signals at a listening spot (very averaged so VERY different from everyone's listening/living room spaces) where direct sound + reflections are accumulated.
The speaker itself should be 'flat' (presumably at 1m on axis in non reverbant room) in order to get a similar MEASUREMENT.

That means, graph that you've attached is target curve of flat loudspeaker in room?

(http://i.imgur.com/DonwmNG.png)

then, you can't evaluate the headphones with those curves you've attached
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: speakerphone on August 14, 2015, 08:10:33 AM
[
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 14, 2015, 08:28:47 AM
That means, graph that you've attached is target curve of flat loudspeaker in room?

then, you can't evaluate the headphones with those curves you've attached

yes, the graph is part of a tutorial I have up somewhere else and not a holy grail by itself, I merely touch on the subject and use it to illustrate.
It's NOT a reference I feel is a holy grail at all.
It seems to represent an 'average' MEASURED frequency response you would see on your analyser when you measure an 'officially flat' speaker (in outside or anechoic circumstances) at 1m on axis from that speaker with a certain dispersion pattern in a 'standard possibly treated' listening ? room (if there is such a thing) with 2 or more octave smooting (so not 1/3 or other).
Someones speakers in their rooms, however, will NEVER be anything like the 'target' some claim is a holy grail for perfect sound.

IF one wants to 'emulate' such a response in a headphone it needs to 'follow' that curve acc to some, others think it needs moar bass, and others feel it needs more treble.

It's just a 'target' to some and nonsense to others.
The early HD650 is pretty close to it when measured on a flat rig but lacks the subbass.


I think headphones that measure like some of the 'target curves' on a rig that measures equal SPL could potentially sound nice and warm with smooth highs which may be a holy grail.
Average recordings may sound decent and excellent recordings may sound too bassy and maybe somewhat too dark.

I prefer a brighter signature, closer to the GE target (flat from say 300Hz and some bass boost).
With such a clearer sounding headphone some recordings sound crap (bright, shrill) but good recordings sound heavenly.

pick your poison.

So for me the whole 'room correction' that acc. to some should be 'incorporated' in the headphones frequency response to emulate speaker sound (what's average speaker sound ?) is nonsense with a bit of merit to it.
From what I know from my own experiments (I don't give a crap about opinions of others) the AQ target (which is what this thread is about) is fishy at least and to me it may sound wrong in tonal balance.
That is wrong when assuming a flat line on THEIR measurement rig (so with the correct compensation) is a flat line in their plots.

So... I hope to see measurements made by others OR they show measurements made on their rig of well documented headphones (HD00 for instance) and also state which headphones they were.
not just say ... 'a flagship's perceieved response as a comparison' that is saying absolutely NOTHING at all.

If its only tonal balance where it is faulted it could well be 'corrected' for me personally with some EQ, mods or a combination.

Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: speakerphone on August 14, 2015, 09:04:47 AM
I see. I didn't think about your measurement rig(what it called? a flatbed?). Actually, I never used that kind of rig to measure the on-ear and over-ear headphones, so I thought that I must compensate DF target on the data.
Title: Re: AudioQuest's Headphone measurements (and its own target headphone frequency)
Post by: Solderdude on August 14, 2015, 09:24:51 AM
I see. I didn't think about your measurement rig(what it called? a flatbed?). Actually, I never used that kind of rig to measure the on-ear and over-ear headphones, so I thought that I must compensate DF target on the data.


My plots are 'compensated' for bass response because I use a mic that is supposed to measure 'flat' in free air when pointed to a source but is mounted mounted on an infinite baflle.
The LF output of the mic differs considerably from when the mic capsule is used 'freely' in the air.
Didn't research this compensation though and might be inaccurate when viewed in an absolute sense but IMO is better than NOT compensate for this effect at all.
Also I removed the small treble peak these capsules show at higher frequencies.
These compensations are done in hardware (electronics) and not in the digital domain nor applied later on 'raw' measurements.
My RAW measurements are thus already 'compensated'.

I don't see the point in adding a Pinna + ear canal + Eustachian tube equivalents and then having to undo everything that those things changed.
All I want to know is the SPL outside of my ear.
Other than that I simply measure the SPL without a Pinna, ear canal nor do I have a 'hard' surface on the measuring 'plane' as ears the skin isn't a hard surface.

Still there will be errors in the measured response but take those for what they are.
I don't claim my measurements are accurate in an absolute sense, only that what I hear has a large correlation to what I measure.

When I see a flat line in my plots HP's tend to sound excellent to my old ears as well.