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Headphone Measurements Using Brüel & Kjær 5128 HATS

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amirm

amirm

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Thread Starter #22
If you aren't using the files from the most recent .xlsx, they're the wrong ones - I mean, the DF is still the same, but the Harman target won't be. My apologies for making that insufficiently clear in our DM, that likely accounts for some of the delta we're describing here.

Should I get them into the AP format and attach them here?
Oh, no! Yes, you can include the right one and i will go back and edit the measurements so far.
 
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amirm

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Thread Starter #23
The channel variations look severe in some of them. Not good to say the least.
As I said, I have not made much of an attempt to equalize them other than levels. Please don't focus on them other than using them for a range of variation that could be caused by the headphone transducer+differences in how they are mounted on the rig.
 
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Thread Starter #24
This is something I'm interested in, would it be possible to measure distortion after EQ? I wonder if you could really just EQ every headphone with significant bass roll off with no significant downsides.
Sure. Would require creating a spreadsheet response of the filter to feed the analyzer for EQ. It only accepts frequency, dB pair values and not filter settings.
 

cistercian

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#26
As I said, I have not made much of an attempt to equalize them other than levels. Please don't focus on them other than using them for a range of variation that could be caused by the headphone transducer+differences in how they are mounted on the rig.
I think the way they are mounted must be critical. I am afraid it may take the whole trial period to get great at.
I am sad you only have such a short time to try it out...it does not seem long enough!
 

BYRTT

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#27
.....We have to targets to compare it to.....

.....This indicates too little bass below 100 Hz or so. There is also lack of energy between 2 and 6 kHz as noted......
Thanks alot man also look into head phone field, i traced Sonarwork avarage profil and overlaid it to yours, forgive me the bad tracing above that 13kHz point where it goes high Q nuts, think not they very close but maybe something myself misunderstand in measurring head phones, find more about the Sonarworks profile is a avarage one below this graph..
AMIR_1.png


This is Sonarwork plugin i traced curve from and its a avarage profile from their experience measure probably tons of HD650, same correction will be added to L/R channels using that universal profile, but they sell measured head phones with dedicated profile for L verse R channel but unfortunate my HD650 is bought at another shop before myself noticed they sell dedicated measured headphones, it can maybe look that in avarage profile of Sonarwork they cautious, say this because later have got a DT770 Pro set from Sonarworks including dedicated correction that run as animation verse the avarage profile for same DT770 Pro cans below the HD650 graph and it can be seen L verse R channel have each their dedicated measurement and correction but also the dedicated correction is huge compared the avarage profile.
SW_HP_compare_HD-650.png

DT-770_Pro_1x1x_1000mS.gif
 
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Mad_Economist

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#28
Oh, no! Yes, you can include the right one and i will go back and edit the measurements so far.
Ah, yes, that explains a bit. Attached are two ways of approaching the 2015 compensation - which I personally would recommend given the atypicalities of the 2018 one: the files named "WELTI" use three in-room positions (simulated via the spreadsheet, of course), the files named "MAD" use a single position with an averaged HRTF (and thus have less indirect sound/diffuse contribution) - I would be interested in your thoughts on both.
 

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#29
Amir, it would be very helpful to see a test of the fixture repeatability - take one headphone, measure it, take it off the fixture, put it back on, measure again. I've seen some measurements which indicate high variability, especially in bass, with headphones seated differently.
 

Mad_Economist

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#31
Amir, it would be very helpful to see a test of the fixture repeatability - take one headphone, measure it, take it off the fixture, put it back on, measure again. I've seen some measurements which indicate high variability, especially in bass, with headphones seated differently.
Note that this parameter is variable per headphone as much as per measurement fixture - moreso, really. Something like the K92 will vary more than the HE400i.

Edit: Keith Howard specifically measures this as a headphone performance parameter, here's an example of his visualization:
stelia confidence.png
 
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#34
A large question. To give one example, the low-frequency response of the K92 will likely vary substantially more depending on sealing with the head than the HE400i's, due to the differences in their acoustics.
Right, this is what I was getting at. I'm sure the B&K fixture is rigid and identical headphone mounting will produce identical results.

I am somewhat concerned with headphones that not only the bass response varies, due to sealing differences, but HF may vary as well.

In other words, as much as I would love to see some headphone measurements, I'd like to see some discussion on the viability of meaningful headphone measurement. I'd be concerned, for example, that the B&K fixture is useful for developing headphones, but less useful for evaluating different designs.
 

Blur

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#35
Few notes:
The 400i looks like the seal is not correct as the bass should be deeper and more linear. They do have peaks in the treble region you measured, but not as high as you have measured.

You can still access Tyll’s work from Innerfidelity by using cdn. in front of the URL. Many of his more recent charts are correct to what I hear. Anything before 2012 will probably be off in a few areas due to the compensation he was using at the time.

There is an AllHeadphoneGraphs URL from Innerfidelity you should be able to get access to. I have them all saved as part of a large PDF I can try and get to you for reference.

Tyll struggled with ear cup seal and he used a 5 position average to get an average of position variance as position is so critical for how the sound couples to the ear.
 

Mad_Economist

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#37
Right, this is what I was getting at. I'm sure the B&K fixture is rigid and identical headphone mounting will produce identical results.

I am somewhat concerned with headphones that not only the bass response varies, due to sealing differences, but HF may vary as well.

In other words, as much as I would love to see some headphone measurements, I'd like to see some discussion on the viability of meaningful headphone measurement. I'd be concerned, for example, that the B&K fixture is useful for developing headphones, but less useful for evaluating different designs.
I rather like Keith's approach of treating variability of response as an aspect of performance - this is something I do in-house as well. Others err towards presenting "best" or "typical" cases - e.g. Tyll Hertsens, Oratory1990.


Few notes:
The 400i looks like the seal is not correct as the bass should be deeper and more linear. They do have peaks in the treble region you measured, but not as high as you have measured.

You can still access Tyll’s work from Innerfidelity by using cdn. in front of the URL. Many of his more recent charts are correct to what I hear. Anything before 2012 will probably be off in a few areas due to the compensation he was using at the time.

There is an AllHeadphoneGraphs URL from Innerfidelity you should be able to get access to. I have them all saved as part of a large PDF I can try and get to you for reference.

Tyll struggled with ear cup seal and he used a 5 position average to get an average of position variance as position is so critical for how the sound couples to the ear.
Note that Tyll's "Independent of Direction" compensation from Head-Acoustics is unlike those used by any other measurement website, and has at best a dubious claim to being even as subjectively well-perceived as diffuse field.
 

restorer-john

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#38
@amirm The high frequencies in pretty much all these headphones are a sea of wild peaks and troughs. Are you confident this rig isn't reflecting/cancelling at these HF frequencies?

Are headphones really that bad at HF?
 

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#40
@amirm The high frequencies in pretty much all these headphones are a sea of wild peaks and troughs. Are you confident this rig isn't reflecting/cancelling at these HF frequencies?

Are headphones really that bad at HF?
I've often wondered this. Cone tweeters of about the same size have similar performance.
 
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