HBK Headphone Measurement Talks from Head-Fi and Sean Olive

[PeteL]

Whether Jude is directly on B&K's payroll, I don't know for sure. But by the prominent display of the B&K logo on all his measurements, it is almost certain that there is arrangement between him and B&K (e.g. significant discount on the gear he got). But that's not the point. The point is apparently for Jude there is not much point in measuring.

OK, I did not know Jude feels there is not much point in measuring. If what you say is really the case Indeed he shouldn't be at this conference. Personally I think we should have something factual to make allegations like that. The Senn Answer is not sufficient to prove something like that. But hey, everything's possible.

 

[Alex-D]

Besides the AKG K371, there are headphones costing less than $100 that come close to the Harman Target like this one.
View attachment 156459

Does Tune 760 (same generation) have the same performance-tuning-etc?
Or is it somehow different due to ANC included?

 

[staticV3]

Does Tune 760 (same generation) have the same performance-tuning-etc?
Or is it somehow different due to ANC included?

Here are four recent JBL headphones, including the 710 and 760, all measured by Dr. Olive:

https://twitter.com/i/web/status/1398359419532967943

 

[MayaTlab]

Does Tune 760 (same generation) have the same performance-tuning-etc?
Or is it somehow different due to ANC included?

Besides @staticV3's link, there's also : https://www.rtings.com/headphones/reviews/jbl/tune-760nc-wireless

 

[pozz]

@Sean Olive Could you please explain why you measure with using a blocked canal instead of at the eardrum using probes? Have you tried using blocking tje canal for the GRAS or BK couplers?

 

[amirm]

@Sean Olive Could you please explain why you measure with using a blocked canal instead of at the eardrum using probes? Have you tried using blocking tje canal for the GRAS or BK couplers?

He explained in the presentation that corporate liability risks don't allow taking measurements with insert microphones.

 

[DualTriode]

@amirm,

This is interesting,

Harman and Sean Olive made much of their research public. Others have joined in and made the new headphone research popular.

@amirm you and others have purchased the same standard GRAS 45CA test Hammer.

Manufacturers like Dan Clark are producing SOTA headphones that you at ASR test and show compliant with the public HAR Target Curve.

Now we get the impression that Harman is licking their wounds and running away with their ball and bat.

Thanks DT

 

[Robbo99999]

@amirm,

This is interesting,

Harman and Sean Olive made much of their research public. Others have joined in and made the new headphone research popular.

@amirm you and others have purchased the same standard GRAS 45CA test Hammer.

Manufacturers like Dan Clark are producing SOTA headphones that you at ASR test and show compliant with the public HAR Target Curve.

Now we get the impression that Harman is licking their wounds and running away with their ball and bat.

Thanks DT

How/what do you mean "licking their wounds & running away with their ball and bat"? Harman are still making headphones that conform quite closely to the Harman Curve, albeit not as closely as the DCA Stealth - it's possible that it's quite tricky to design passive headphones to conform smoothly to the Harman Curve and a company probably wouldn't want all of their designed headphones to hug the Harman Curve in exactly the same way as it proves not enough differentiation between products to cater for various niches (probably grouped around bass level desired perhaps). As an avid headphone EQ'er I'm aware that different models of headphone do not sound the same when EQ'd to the same Harman Curve, but still a company producing headphones would not design each of their headphones to follow the same curve.......not unless they were heavily marketing some other aspects of their headphones that extended beyond the frequency response to allow for differentiation.

 

[DualTriode]

How/what do you mean "licking their wounds & running away with their ball and bat"? Harman are still making headphones that conform quite closely to the Harman Curve, albeit not as closely as the DCA Stealth - it's possible that it's quite tricky to design passive headphones to conform smoothly to the Harman Curve and a company probably wouldn't want all of their designed headphones to hug the Harman Curve in exactly the same way as it proves not enough differentiation between products to cater for various niches (probably grouped around bass level desired perhaps). As an avid headphone EQ'er I'm aware that different models of headphone do not sound the same when EQ'd to the same Harman Curve, but still a company producing headphones would not design each of their headphones to follow the same curve.......not unless they were heavily marketing some other aspects of their headphones that extended beyond the frequency response to allow for differentiation.

Hello,

What do I mean?

They are no longer using the Gras 45CA Test Hammer. They have moved to the HATS. The new HAR Test Curve is not compliant with the old GRAS 45CA HAR Test Curve.

When asked, Sean Olive replied that there was no direct conversion between the GRAS 45CA measurements and the HATS measurements.

We are now talking apples and oranges.

Harman is distancing themselves from the old public research and old GRAS 45CA HAR Test Curve. Running away with their ball and bat.

Thanks DT

 

[Robbo99999]

Hello,

What do I mean?

They are no longer using the Gras 45CA Test Hammer. They have moved to the HATS. The new HAR Test Curve is not compliant with the old GRAS 45CA HAR Test Curve.

When asked, Sean Olive replied that there was no direct conversion between the GRAS 45CA measurements and the HATS measurements.

We are now talking apples and oranges.

Harman is distancing themselves from the old public research and old GRAS 45CA HAR Test Curve. Running away with their ball and bat.

Thanks DT

Oh right, holy shit! I must admit I've not looked at his slides in detail. So how did they come up with a new Harman Curve for the new test rig? What's the model name/number of the new test rig?

 

[amirm]

They are no longer using the Gras 45CA Test Hammer. They have moved to the HATS. The new HAR Test Curve is not compliant with the old GRAS 45CA HAR Test Curve.

What? They have made no such statement. FYI they have had the BK 5128 for a long time and were one of the first customers of it. So it is not something they just bought and are moving toward it. Since they own, they are going to use it in the future but I saw noting in the presentation to indicate they are moving away from GRAS 45CA. Indeed the opposite because that is still the gold standard that matches their multiyear extensive research.

 

[amirm]

Now we get the impression that Harman is licking their wounds and running away with their ball and bat.

Harman is not in the business of making $4,000 headphones. So nothing in the development of the DC Stealth impacts what they are doing in the least. If anything, it gets more people exposed to the correct headphone response which they (Harman) offer at much lower prices.

 

[Robbo99999]

Hello,

What do I mean?

They are no longer using the Gras 45CA Test Hammer. They have moved to the HATS. The new HAR Test Curve is not compliant with the old GRAS 45CA HAR Test Curve.

When asked, Sean Olive replied that there was no direct conversion between the GRAS 45CA measurements and the HATS measurements.

We are now talking apples and oranges.

Harman is distancing themselves from the old public research and old GRAS 45CA HAR Test Curve. Running away with their ball and bat.

Thanks DT

Oh right, you're talking about the B&K, you've misinterpreted it then, it's of no current consequence, I thought you were talking about some other work....move on, move on, nothing to see here!

What? They have made no such statement. FYI they have had the BK 5128 for a long time and were one of the first customers of it. So it is not something they just bought and are moving toward it. Since they own, they are going to use it in the future but I saw noting in the presentation to indicate they are moving away from GRAS 45CA. Indeed the opposite because that is still the gold standard that matches their multiyear extensive research.

 

[_thelaughingman]

Thinking of the situation with the various head fixtures and measurements tools, made me think of the need to have a set QC and calibration curve. I am an engineer and a licensed medical lab tech and in lab medicine they utilize a calibration curve and QC to measure the performance of test assays. In the same vein, would it be wise to setup a calibration curve and QC that conforms to a universal standard for a fixture. I think what should be done for GRAS, or B&K to have some uniformity is to compile a calibration curve that can be used as a baseline and once that baseline is used for calibrating the fixture, testing should be and would be accepted as conforming to a standard ie: Harman Curve or Diffuse Field.

 

[Robbo99999]

Thinking of the situation with the various head fixtures and measurements tools, made me think of the need to have a set QC and calibration curve. I am an engineer and a licensed medical lab tech and in lab medicine they utilize a calibration curve and QC to measure the performance of test assays. In the same vein, would it wise to setup a calibration curve and QC that conforms to a universal standard for a fixture. I think what should be done for GRAS, or B&K to have some uniformity is to compile a calibration curve that can be used as a baseline and once that baseline is used for calibrating the fixture, testing should be and would be accepted as conforming to a standard ie: Harman Curve or Diffuse Field.

It is possible to try to calibrate one fixture against another by for instance comparing lots of different headphone measurements on one unit vs the same measurements on another, and that's better than a kick in the head in terms of creating a new "Harman Curve" for a new fixture but it's not an accurate process. For instance, I used a K702 Harman EQ that had been done from an Innerfidelity measurement which is not a GRAS fixture, but it was using a Target Curve that had been derived by jaakopasenen in his AutoEQ project by comparing lots of the same different models of headphones measured on the Innerfidelity unit vs the same models on the GRAS unit....as a means of converting the Harman Curve from GRAS to whatever fixture Innerfidelity was using. Anyway, I sent x2 units of K702 to Oratory for him to measure on his GRAS unit, from which he created his K702 measurement & EQ....which is really quite different than the "Harman Curve EQ" that had been done from the Innerfidelity measurements from their "calibration process" of comparing headphones measured on that vs a GRAS unit as earlier described in this post. So it's just not an accurate conversion method of transferring over the preferred frequency response that was derived from the Harman Research. So unfortunately I don't think any kind of conversion process from one test fixture to another is valid unless the preference research work is done from scratch, however it is better than a kick in the head if your headphone hasn't been measured on a GRAS fixture on which the research was originally based.

 

[Sean Olive]

Hello,

What do I mean?

They are no longer using the Gras 45CA Test Hammer. They have moved to the HATS. The new HAR Test Curve is not compliant with the old GRAS 45CA HAR Test Curve.

When asked, Sean Olive replied that there was no direct conversion between the GRAS 45CA measurements and the HATS measurements.

We are now talking apples and oranges.

Harman is distancing themselves from the old public research and old GRAS 45CA HAR Test Curve. Running away with their ball and bat.

Thanks DT

Where have I said we are “distancing ourselves from our research and the GRAS 45 CA?”

You may have noticed the pictures of a GRAS 45CA on my dining room shown in the Audioholics video. I paid for this out of my own pocket. We also measure all pf our headphones at Harman on a similar unit.

We are applying this research to our headphones and will continue to do so until there is new knowledge showing a better approach. We own many different test fixtures including a 5128. This doesn’t mean we have abandoned GRAS 45CA. It just means we want to understand how the different test fixtures vary so we can better interpret measurements made on them. Nothing more.

 

[DualTriode]

Where have I said we are “distancing ourselves from our research and the GRAS 45 CA?”

You may have noticed the pictures of a GRAS 45CA on my dining room shown in the Audioholics video. I paid for this out of my own pocket. We also measure all pf our headphones at Harman on a similar unit.

We are applying this research to our headphones and will continue to do so until there is new knowledge showing a better approach. We own many different test fixtures including a 5128. This doesn’t mean we have abandoned GRAS 45CA. It just means we want to understand how the different test fixtures vary so we can better interpret measurements made on them. Nothing more.

Thank you.

I also purchased a GRAS 45 CA-9 (the -9 is externally powered otherwise same same) out of my own pocket.

You note in your slides, “Important to note that the GRAS 45 CA-10 uses a different coupler (RA0402) and different pinna (KB7001/2) from that used to develop the Harman Target Curve & these are not accounted for in the ASR application of the Harman Target.”

I intend to extrapolate a calibration curve to use in the APx software to bring my measurements closer to the Gold Standard Harman Target.

Thanks DT

 

[Jimbob54]

Am quite sure it would be the AKG K371 and possibly also new JBL 710 from his past postings.

I asked a similar question of Dr O a while back

I get the sense he isnt a head-fi fanatic and unsurprisingly utilises what I am sure is easily available to him (bet he has a pair of Sennheiser HD600 tucked away somewhere out of sight as a guilty pleasure though )

Headphones preference score ranking chart based on Harman target curve

Even when only comparing tonality, they should take "mortal sins" into account. The HD681 (ranking at 61) with their eardrum-shredding highs are a good example, they might be ok for my half deaf grandpa, but I, being in my early twenties, simply can not use them without EQ. I happen to own one...

www.audiosciencereview.com

 

[Sean Olive]

Thank you.

I also purchased a GRAS 45 CA-9 (the -9 is externally powered otherwise same same) out of my own pocket.

You note in your slides, “Important to note that the GRAS 45 CA-10 uses a different coupler (RA0402) and different pinna (KB7001/2) from that used to develop the Harman Target Curve & these are not accounted for in the ASR application of the Harman Target.”

I intend to extrapolate a calibration curve to use in the APx software to bring my measurements closer to the Gold Standard Harman Target.

Thanks DT

Yes. The differences between the the RA0042 (mine) and the RA 0045 are mostly the damped resonance at 13.kHz in mine. There are some differences in the anthropomorphic pinna and Todd Welti’s custom pinna above 3-4khz which I’ve captured in this study.

 

[Sean Olive]

I asked a similar question of Dr O a while back

I get the sense he isnt a head-fi fanatic and unsurprisingly utilises what I am sure is easily available to him (bet he has a pair of Sennheiser HD600 tucked away somewhere out of sight as a guilty pleasure though )

Headphones preference score ranking chart based on Harman target curve

Even when only comparing tonality, they should take "mortal sins" into account. The HD681 (ranking at 61) with their eardrum-shredding highs are a good example, they might be ok for my half deaf grandpa, but I, being in my early twenties, simply can not use them without EQ. I happen to own one...

www.audiosciencereview.com

I have a lot of the expensive headphones too but the measurements aren’t much better or often worse than the ones I mentioned.