ASR Getting Into Measuring Headphones!

[DualTriode]

Tests like this are only useful for designers searching for something specific. Ditto for CSD/waterfall/time domain response, etc. For end-customers, they only serve to confuse and add noise to otherwise useful measurement.

We may occasionally use them on digging deep on "why" something is the way it is. But as a routine measure, they are not useful. This is why I don't post waterfalls for speakers even though I secretly run them all the time .

I have a mechanical engineers’ brain. I have been taking things apart to see how they tick since I could pick up a hammer.

@amirm, I will be following how you do things, I am interested in how you will put together your Headphone dashboard and testing protocol. I will mostly stay out of the way.

A couple of things that I will look at are driver stored energy aka resonance and driver distortion.

Thanks DT

 

[the_brunx]

YEEESSSSSS! Now FINALLY someone can measure headphone distortion figures to find out which is the ultimate headphone in terms of transparency and not just the vague frequency response measurements which are not accurate anyway to the received sound by the brain because everyone has a unique hearing frequency response and everyone can use an eq to correct all this for personal optimisation, making frequency response measurements quite irrelevant if you ask me. but there is not any correction possibility for headphone's distortion. So this should be looked at with the utter most importance!!!

I am celebrating this, because this is the closest we have ever gotten to accurately knowing a lot about the fidelity of the end sound without hearing it ourselves.

 

[amirm]

Comfort is such a critical component of the overall headphone experience. Many aspects are subjective but some values can still be expressed objectively: clamping pressure/force and earpad dimensions are two major factors in comfort that never get expressed. What do you guys think of adding data like that to the reviews?

Even if we could measure such things, translation into personal comfort will be tough. I am open to ideas though.

 

[amirm]

@amirm, I will be following how you do things, I am interested in how you will put together your Headphone dashboard and testing protocol. I will mostly stay out of the way.

You have the closest set up to what I have for measurements. Hopefully your resources can also be put to good use as well.

 

[Cahudson42]

You have to export the data and plot it externally which is time consuming and a pain in the neck.

Perhaps a 'volunteer' may arise to do it - as with @MZKM with Preference?

 

[the_brunx]

This will put headphone reviewers out of business. LOL

 

[Cahudson42]

This will put headphone reviewers out of business.

Well, hopefully. But I have found one totally subjectivist reviewer where at least it seems the same terms are used with different descriptors to describe different HP.

No measurements at all. Might be interesting in future to 'map' his subjectivist comments against objectivist measurements..

 

[amirm]

Perhaps a 'volunteer' may arise to do it - as with @MZKM with Preference?

I just looked and the export of such data requires an optional module for Audio Precision. So I don't think it is in the cards for now but let me ponder on that....

 

[Illtrick]

Even if we could measure such things, translation into personal comfort will be tough. I am open to ideas though.

I don’t think it needs to start with an understanding of how to express the data points against a comfort index. Relational data is helpful. Example clamp force on my AKG Q701 is just right for my head size so I’d look for similar force values.

 

[maverickronin]

This will put headphone reviewers out of business. LOL

Tyll Hertsens measured headphones from the very beginning of audiophile headphones being a "thing" and reviewers never had a problem finding an audience. One more person with a slightly more accurate rig does not a revolution make.

 

[DualTriode]

Just playing with the AP CSD software with LCD-2 with fasor headphones.

DT

 

[m8o]

max SPL

Wouldn't that need to be a destructive test to be accurate?

 

[bobbooo]

Well, hopefully. But I have found one totally subjectivist reviewer where at least it seems the same terms are used with different descriptors to describe different HP.

No measurements at all. Might be interesting in future to 'map' his subjectivist comments against objectivist measurements..

Actually he does do measurements, now with the GRAS 43AG, very similar to here, and the exact same model RA0402 'hi-res' coupler.

 

[DualTriode]

Actually he does do measurements, now with the GRAS 43AG, very similar to here, and the exact same model RA0402 'hi-res' coupler.

crinacle.com does the measurements

 

[bobbooo]

crinacle.com does the measurements

This is false. Resolve (Andrew Park) does his own measurements for headphones.com. Crinacle's measurements are completely separate to those. Source:

https://forum.headphones.com/t/hifm...-magnetic-headphones-official-thread/3248/209

 

[solderdude]

Just playing with the AP CSD software with LCD-2 with fasor headphones.

DT

View attachment 97666View attachment 97668

LCD2-Fazor CSD:

LCD2-Fazor distortion:

 

[Cahudson42]

LCD2-Fazor CSD:

Wow! What a difference from the HE400i (Mine )

 

[Kyle / MrHeeHo]

Since you already have the Ether CX I'm curious to see if the filters it comes with are actually enough to impact the sound

 

[bidn]

Comfort is such a critical component of the overall headphone experience. Many aspects are subjective but some values can still be expressed objectively: clamping pressure/force and earpad dimensions are two major factors in comfort that never get expressed. What do you guys think of adding data like that to the reviews?

I agree with you, Illtrick.

Let's not forget about something VERY IMPORTANT, even more important for headphones, if not the most important re. comfort, as one may wear them for long sessions :
their WEIGHT !
This is easy to measure, using a kitchen scale.

Even if we could measure such things, translation into personal comfort will be tough. I am open to ideas though.

Ideally there would be two measurements :

# 1 weight with cables attached

# 2 weight without cables
(if detachable, which is unfortunately often not the case for electrostatic headphones).
This second measurement would be relevant for 3 reasons:
- allows comparing the weight of cabled headphones independently from cables
- essential for wireless headphones
- allows better comparisons between headphones intended for wired use and those intended to be mainly used wirelessly.

Weight is more generally usefull than pressure, as humans have varying skull dimensions (incl. width).

Usually people agree that 500 grams is a good demarcation threshold, i.e. those heavier than 500 g are in the red zone of too much weight (for long wearing sessions), weight above 500 g can be seen as disqualifying for generally appropriate headphones.

Re. science, all measurements should be with scientific units: grams, millimeters ...
(conversions to imperial units could also be added, I personally have no need for these conversions).

 

[MZKM]

Wouldn't that need to be a destructive test to be accurate?

Not if you set distortion thresholds.
Amir isn’t going to send 100W into a headphone.

What thresholds to choose matter, and heavily debatable. I think I said this for speakers, but I think the following is a good middle ground:
100Hz: -20dB
1000Hz: -30dB
10000Hz: -40dB

You will however have issues, like for instance a really high-Q distortion peak. Or, a very high-Q dip in the frequency response which makes the resulting distortion % really high even though it’s the same absolute level for neighboring frequencies. And unlike speakers, headphones aren’t supposed to have a flat uncompensated frequency response, so it’d be hard to take the distortion relative to the average level.