Sennheiser HD 650/HD 6XX

[Grave]

Have you heard the HD58x or are you just going by the measurements? It seems like you and me are two of the few dissenting opinions on the HD58x, though I would use far from the juvenile Headfi-esque term of "sounds like ass".

I do intend to try some of these mods as long as they are reversible.

I own the HD 58X although I gave up even listening to them after a few hours. See the original post.

 

[solderdude]

Do you have measurements of your modified HD58x overlayed with the HD650.

modified + filtered HD58X vs stock HD650 (2017 version)



Below the only modified but NOT filtered HD58X vs HD650 (2017 version) but with a different overlay.




and for completeness: stock HD58X vs HD650 (2017 version)

 

[dc655321]

modified + filtered HD58X vs stock HD650 (2017 version)



and for completeness: stock HD58X vs HD650 (2017 version)

@solderdude what fittings have been applied to these measurements?

 

[solderdude]

E27 or E14 ?

No idea what you mean with fittings..., but where I live a 'fitting' is the metal part lightbulb.
When you mean my reference to 'filtered' it is a filter that lowers the 5kHz peak.

 

[dc655321]

No idea what you mean with fittings

Fitting was a poor choice of wording on my part. Let me try again...
What "compensation curve" was applied to the raw measurement data?

 

[solderdude]

as described here... have to scroll down a bit below the measurement links.
There is also a peak of a few dB with a certain bandwidth at 16kHz which is known for the used mic when mounted on an infinite baffle and this is compensated for. The correction curve above is 'my version' of perceived bass correction for headphones a bit like O-W but not as 'extreme' and following a natural curve instead of a steep curve.

 

[dc655321]

as described here... have to scroll down a bit below the measurement links.
There is also a peak of a few dB with a certain bandwidth at 16kHz which is known for the used mic when mounted on an infinite baffle and this is compensated for. The correction curve above is 'my version' of perceived bass correction for headphones a bit like O-W but not as 'extreme' and following a natural curve instead of a steep curve.

Ah. Roll-your-own. Got it.

 

[solderdude]

Indeed, there is no real 'standard' for 'perceived bass' correction and as my rig is DIY anyway it is a roll-your-own, just like any other DIY rig.
And like the one from Golden Ears, Rtings, Sonarworks and O-W who all have similar-ish 'corrections' based on their findings.
Mine is closest to Rtings and Goldenears and less 'extreme' as that from Sonar works.
yep .. no standard.
Headphone measurements cannot be compared between each other anyway, only between measurements on the same rig and under same conditions.
My attempt to 'link' perceived tonal balance to (my) measurements at around 80dB SPL average levels.
No Pinna either so Concha gain is not 'included'.

 

[dc655321]

Headphone measurements cannot be compared between each other anyway, only between measurements on the same rig and under same conditions.

Still, I prefer to see non-compensated measurements.
IMO, conflating measurement and perception is a lost battle (with headphones).
At least until there exists a followed standard, permitting replication of raw measurements...

 

[solderdude]

In that case, now that my 'correction' is known, you can 'un-correct' my measurements and see them as 'raw'.
When I started out with measuring I did not 'compensate' but soon found the plots did not 'match' with how I perceived them compared to real music and reproductions on excellent speakers.
I searched everywhere for info as to why and how much. Eventually after much comparisons, measurements, reading and the theory that most things in life follow 'natures' rules I came up with my own.

Non compensated measurements from different brand HATS also can not be compared directly as well and are virtually 'unreadable' to me as the 'earcanal and Pinna' corrections are impossible to know and 'subtract' in ones mind.
Those from other DIY'ers also vary wildly. Not only in the bass but even more so in the treble above 3kHz.
Which one would get the trophy to be the most 'correct' WRT to how headphones measure and are perceived ?
Well... that may be dependent on personal opinions, tonal preferences, friendships/loyalty to certain 'measurers', physical constructions, microphones used (mostly not designed for infinite baffle band to be used in free air at minimal distances to be 'flat') which are stuck close to the driver in (partly or not) sealed chambers which may or may not reflect or (over)damp.

This is why I think there will probably never be a 'standard' as that would have to be 'created' under specific circumstances on 1 particular rig (Harman is trying to) with 1 type of 'universal' Pinna (does an average pinna exist ?) and all made of a specified material and all other brands would either have to calibrate to that particular (compensated) measurement rig having the exact same 'average' Pinna.
Not going to happen I think.
Patents, standards, rights, money.... more money and no DIY'er can ever calibrate to such a (probably crazy expensive) rig anyway.

 

[andreasmaaan]

as described here... have to scroll down a bit below the measurement links.
There is also a peak of a few dB with a certain bandwidth at 16kHz which is known for the used mic when mounted on an infinite baffle and this is compensated for. The correction curve above is 'my version' of perceived bass correction for headphones a bit like O-W but not as 'extreme' and following a natural curve instead of a steep curve.

FWIW, your compensation curve seems to quite closely match the Harman curve* in the bass, where the pinnae have the least (if any) impact on the FR.

*Actually it closely matches the inverse of the Harman curve, which makes sense given that the Harman curve is not a compensation curve but rather a desired raw response curve.

 

[dc655321]

Which one would get the trophy to be the most 'correct' WRT to how headphones measure and are perceived ?

Perception/interpretation aside, the "trophy" goes to the technique leading to (raw) measurements that are repeatable between rigs.

Thus my point: perception-compensation is useless if one is applying them to a moving or ill-defined (non-repeatable) target.
I have difficulty understanding why experimenters insist on trying to account for the variability of human anatomy and perception without having first established a reliable means of measuring of an earphones' transfer function.

At any rate, thanks for your insights on this subject.
Headphone measurements are a source of frustration for me.

 

[andreasmaaan]

Headphone measurements are a source of frustration for me.

For us all!

 

[pkane]

This is why I think there will probably never be a 'standard' as that would have to be 'created' under specific circumstances on 1 particular rig (Harman is trying to) with 1 type of 'universal' Pinna (does an average pinna exist ?) and all made of a specified material and all other brands would either have to calibrate to that particular (compensated) measurement rig having the exact same 'average' Pinna.
Not going to happen I think.
Patents, standards, rights, money.... more money and no DIY'er can ever calibrate to such a (probably crazy expensive) rig anyway.

Agreed. There is probably no such thing as 'universal' or even 'average' pinna in existence. I've been having fun measuring my ear FR using in-ear mics, and my left ear has a different response than my right ear. Why would I expect that some average would be a good fit? By the way, compensating for this, my personal, measured, in-ear response produces some of the best headphone sound I've heard to date. Here are left and right in-ear measurements with HE-560s:

 

[andreasmaaan]

Agreed. There is probably no such thing as 'universal' or even 'average' pinna in existence. I've been having fun measuring my ear FR using in-ear mics, and my left ear has a different response than my right ear. Why would I expect that some average would be a good fit? By the way, compensating for this, my personal, measured, in-ear response produces some of the best headphone sound I've heard to date. Here are left and right in-ear measurements with HE-560s:

View attachment 15128

Just to try to understand better what you're doing, are you EQing this measured response to achieve a flat response or something else?

 

[pkane]

Just to try to understand better what you're doing, are you EQing this measured response to achieve a flat response or something else?

Yes, my first attempt was to produce a flat line. It sounded good, but just a tad too bright. Then, I adjusted it to a flat line 5dB down from 20 to 20KHz, and it sounded simply awesome. A 10dB down flat line sounded too bass-heavy.

 

[andreasmaaan]

Yes, my first attempt was to produce a flat line. It sounded good, but just a tad too bright. Then, I adjusted it to a flat line 5dB down from 20 to 20KHz, and it sounded simply awesome. A 10dB down flat line sounded too bass-heavy.

What in-ear mics are you using? Would be interested to try to replicate this process myself.

 

[solderdude]

Perception/interpretation aside, the "trophy" goes to the technique leading to (raw) measurements that are repeatable between rigs.

Is it the technique that is the problem or the manufacturers competence/capabilities/tolerances in manufacturing or their 'correction/compensation' or does 'some' notified body has to establish a 'standard' first to which manufacturers have to comply ?

 

[pkane]

What in-ear mics are you using? Would be interested to try to replicate this process myself.

https://www.soundprofessionals.com//cgi-bin/gold/category.cgi?item=SP-TFB-2-13099P

These are a bit positional, but I find if I get them fitted in snuggly, the measurements are repeatable. These need 12v phantom supply, the usual 48v will fry them.

 

[solderdude]

Here are left and right in-ear measurements with HE-560s:

View attachment 15128

A question... (Have wrestled with similar issues)

Are the measured differences between the ears the result of:
A: The Pinnae/HRTF
B: The L-R difference between the HE-560 drivers
C: the exact angles/position of the mics differing
D: differences between mics
E: different positions of the drivers on the head
F: differences in gain between L and R mic-pre-ADC ?
G: Is the mic measuring 'flat' when inside an ear cavity ?

or ... a mix of any or all of the above ?

There are so many variables/unknowns here and differences of 2 dB are quite audible. I see differences well over 6dB here and there.
What I have found is that when creates 'sharp' filters to fill in dips or lower peaks that this rarely leads to worthwhile compensations.
Heavy 'smoothing' or using wide filters seems to produce the best (sonic) results, when one can rely on the measurement gear being 'flat' as the reference. And only then when the corrections needed are small.

Did you swap L and R driver (and the pads as they are angled ?) to check for differences between the drivers ?
What FR differences do you get with different mic orientations ?
How does one check FR differences in the mic circuit ?
Can the mics themselves be swapped between L and R earpiece or are they 'fixed' to the ear clamp ?

I have played with in-ear mics (different ones) as well and found them highly unreliable and incapable of producing repetitive results within a few dB over the entire FR range so gave it up.
It proved impossible to get meaningful results for me especially in distortion measurements due to mechanically coupled sounds.
How can one build a reliable compensation on this is a question that comes forward ?