Headphone Measurements: The New Standard, Part 1
post-15758030
Post #31 of 42
Joined
Oct 18, 2017
Messages
648
Reaction score
1,575
Location
Seattle, WA
Joined
Oct 18, 2017
Location
Seattle, WA
Posts
648
Likes
1,575
What are the thoughts on the GRAS RA0402 coupler in regards to the new 5128? I love that a new approach and standard has come about though, so cool! I'm a fan of more information is better than less :wink: lol... a great read, and I look forward to the next portions and future updates as you learn and share your experiences @jude
 
headphones.com Stay updated on headphones.com at their sponsor profile on Head-Fi.
 
https://www.headphones.com/ andrew@headphones.com
     Share This Post       
post-15761738
Post #33 of 42

eldus

100+ Head-Fier
Joined
Mar 23, 2015
Messages
393
Reaction score
47
Location
MN
Joined
Mar 23, 2015
Location
MN
Posts
393
Likes
47
AKG K240 test when? lol. Will there be a section for measurements on the site?
 
     Share This Post       
post-15764945
Post #34 of 42

castleofargh

Sound Science Forum Moderator
Joined
Jul 2, 2011
Messages
9,016
Reaction score
4,354
Joined
Jul 2, 2011
Posts
9,016
Likes
4,354
We all hear highs differently?

Hmmm....
All, maybe not. But you can expect some variations between people. Just your left and right ears being of slightly different shapes, probably cause significant high freq differences at the eardrums. As to why high freqs and not so much lower frequencies? Well that's because high frequencies have shorter wavelengths. It's just physics. Being shorter, they are impacted more by smaller variations in shapes, volumes, distances(reflections, resonances). But of course it's not strictly limited to high frequencies.

There is another possible cause of perceived variations, it's the fact that our subjective experience of sound is always that of some waves bouncing on our body and being altered by it before reaching the eardrum. That's our constant experience of real sound and we're so used to it that our brain actually uses those as cues to locate the sound source. With headphones and IEMs, the sound source bypasses some of those acoustic changes from our body(because the driver is so close to the ear). That could ironically lead to hearing a sound closer to what another listener will hear, yet feel more differences in our subjective impressions. Because our brain is still applying the usual mental and personal compensation(think EQ in this specific context of measuring FR with dummy heads) onto a signal that only needed part of it. So you and I might listen to the same headphone and feel more differences in our experience of the signature than when we're both listening to a guy playing the guitar while sitting close to each other.

And the third possible cause for change: placement. How we put on the headphone. How tight is the clamp because of the size of our skull and forcing the driver a little closer as a result. How far we insert the IEM. All that will have some impact on the sound reaching the eardrum.
 
post-15764987
Post #35 of 42

sidecross

100+ Head-Fier
Joined
Dec 26, 2018
Messages
460
Reaction score
168
Location
North America
Joined
Dec 26, 2018
Location
North America
Posts
460
Likes
168
All, maybe not. But you can expect some variations between people. Just your left and right ears being of slightly different shapes, probably cause significant high freq differences at the eardrums. As to why high freqs and not so much lower frequencies? Well that's because high frequencies have shorter wavelengths. It's just physics. Being shorter, they are impacted more by smaller variations in shapes, volumes, distances(refl of ralityections, resonances). But of course it's not strictly limited to high frequencies.

There is another possible cause of perceived variations, it's the fact that our subjective experience of sound is always that of some waves bouncing on our body and being altered by it before reaching the eardrum. That's our constant experience of real sound and we're so used to it that our brain actually uses those as cues to locate the sound source. With headphones and IEMs, the sound source bypasses some of those acoustic changes from our body(because the driver is so close to the ear). That could ironically lead to hearing a sound closer to what another listener will hear, yet feel more differences in our subjective impressions. Because our brain is still applying the usual mental and personal compensation(think EQ in this specific context of measuring FR with dummy heads) onto a signal that only needed part of it. So you and I might listen to the same headphone and feel more differences in our experience of the signature than when we're both listening to a guy playing the guitar while sitting close to each other.

And the third possible cause for change: placement. How we put on the headphone. How tight is the clamp because of the size of our skull and forcing the driver a little closer as a result. How far we insert the IEM. All that will have some impact on the sound reaching the eardrum.
Add to what has been written above, our individual brain and consciousness is an interpretation of reality.

When it comes down to evaluation, hearing is an art and not subject to a true absolute, and is a reason music as art is a human characteristic.
 
     Share This Post       
  • Like
Reactions: Mshenay and halcyon
post-15769178
Post #36 of 42

TYATYA

1000+ Head-Fier
Joined
Mar 6, 2011
Messages
1,085
Reaction score
340
Location
Center of sound stage
Joined
Mar 6, 2011
Location
Center of sound stage
Posts
1,085
Likes
340
Error of measurement makes me always to do sine sweep a headphone, earphone by my gear and judgement by my ears.
Shure kse looks bad graph of FR but to my ears, only narrow peak at 6300Hz existing, not at 9k and not so high sound pressure
 
Last edited:
     Share This Post       
post-15785569
Post #37 of 42
Joined
Mar 23, 2009
Messages
5,608
Reaction score
1,506
Joined
Mar 23, 2009
Posts
5,608
Likes
1,506
We all hear highs differently?

Hmmm....
Yes, @castleofargh made a great intro post covering most of the info!

All, maybe not. But you can expect some variations between people. Just your left and right ears being of slightly different shapes, probably cause significant high freq differences at the eardrums. As to why high freqs and not so much lower frequencies? Well that's because high frequencies have shorter wavelengths. It's just physics. Being shorter, they are impacted more by smaller variations in shapes, volumes, distances(reflections, resonances). But of course it's not strictly limited to high frequencies.

There is another possible cause of perceived variations, it's the fact that our subjective experience of sound is always that of some waves bouncing on our body and being altered by it before reaching the eardrum. That's our constant experience of real sound and we're so used to it that our brain actually uses those as cues to locate the sound source. With headphones and IEMs, the sound source bypasses some of those acoustic changes from our body(because the driver is so close to the ear). That could ironically lead to hearing a sound closer to what another listener will hear, yet feel more differences in our subjective impressions. Because our brain is still applying the usual mental and personal compensation(think EQ in this specific context of measuring FR with dummy heads) onto a signal that only needed part of it. So you and I might listen to the same headphone and feel more differences in our experience of the signature than when we're both listening to a guy playing the guitar while sitting close to each other.

And the third possible cause for change: placement. How we put on the headphone. How tight is the clamp because of the size of our skull and forcing the driver a little closer as a result. How far we insert the IEM. All that will have some impact on the sound reaching the eardrum.
Yes! This is born out in testing.
Just to add one more thing to what is written above: you mention high frequencies have shorter wavelengths, and sound being altered before reaching the eardrum. Not too long ago I learned that our ears actually have a resonant frequency in the highs. All tubes have a resonant frequency where the wavelength is reinforced by the cylindrical structure... just like when you're humming in the shower, you might notice a pitch that suddenly is louder and the space seems to hum with you (If you haven't tried this yet... it's fun to find the right pitch, makes you feel powerful!). Now our ear canals are much narrower, thus the frequency is higher, and as evident by all our different IEM ear tip size needs, we have different resonant frequencies.

This is why I found Jude's "T-1000" gif so funny... and an apt consideration of the trickiness of ear simulators. Not only are our outer ears different to some degree, so is the diameter and bend of our inner ears. I would like to know more about the material used for ear simulation... is the silicone a close enough approximation of how reverberant and absorptive our skin is? And how much of an effect does the hairs on our skin affect the sound, especially as I notice some of my ear hair growing longer, haha!

Keep this in mind next time someone says the treble is too hot or too weak... it might not be their preferences, hearing damage, or psychoacoustics, it could just be their different physiology (at least partially).
 
Sennheiser Stay updated on Sennheiser at their sponsor profile on Head-Fi.
 
https://www.facebook.com/SennheiserUSA https://twitter.com/SennheiserUSA http://www.instagram.com/sennheiser https://sennheiser.com/
     Share This Post       
post-15786002
Post #38 of 42

Piotr Michalak

100+ Head-Fier
Joined
Nov 27, 2016
Messages
430
Reaction score
344
Joined
Nov 27, 2016
Posts
430
Likes
344
Headphone Measurements: The New Standard, Part 1
Wrote to these guys for a quote. Received no response. I understand that these hats are not cheap. But straight ignoring a potential prospect doesn't lead to sales either. Maybe these are reserved for established brands only? But then, why publish videos on youtube and head-fi and have a contact form, rather than just make selective sales and presentations? I wanna build a professional rig. However if almost no one publishes these new-standard measurements and almost no one has this thing, what's the value of this? We will only see a measurement from Jude once in a while maybe?
 
     Share This Post       
  • Like
Reactions: halcyon
post-15786530
Post #39 of 42

halcyon

Headphoneus Supremus
Joined
Oct 21, 2002
Messages
1,792
Reaction score
158
Joined
Oct 21, 2002
Posts
1,792
Likes
158
Wrote to these guys for a quote. Received no response. I understand that these hats are not cheap. But straight ignoring a potential prospect doesn't lead to sales either. Maybe these are reserved for established brands only? But then, why publish videos on youtube and head-fi and have a contact form, rather than just make selective sales and presentations? I wanna build a professional rig. However if almost no one publishes these new-standard measurements and almost no one has this thing, what's the value of this? We will only see a measurement from Jude once in a while maybe?

Hey, it's a Danish company, what do you expect? :beyersmile:
 
     Share This Post       
  • Like
Reactions: Piotr Michalak
post-15786591
Post #40 of 42

Mshenay

Headphoneus Supremus
Joined
Mar 30, 2012
Messages
15,478
Reaction score
1,480
Joined
Mar 30, 2012
Posts
15,478
Likes
1,480
Website
oakforestaudio.blogspot.com
Yes, @castleofargh made a great intro post covering most of the info!


Yes! This is born out in testing.
Just to add one more thing to what is written above: you mention high frequencies have shorter wavelengths, and sound being altered before reaching the eardrum. Not too long ago I learned that our ears actually have a resonant frequency in the highs. All tubes have a resonant frequency where the wavelength is reinforced by the cylindrical structure... just like when you're humming in the shower, you might notice a pitch that suddenly is louder and the space seems to hum with you (If you haven't tried this yet... it's fun to find the right pitch, makes you feel powerful!). Now our ear canals are much narrower, thus the frequency is higher, and as evident by all our different IEM ear tip size needs, we have different resonant frequencies.

This is why I found Jude's "T-1000" gif so funny... and an apt consideration of the trickiness of ear simulators. Not only are our outer ears different to some degree, so is the diameter and bend of our inner ears. I would like to know more about the material used for ear simulation... is the silicone a close enough approximation of how reverberant and absorptive our skin is? And how much of an effect does the hairs on our skin affect the sound, especially as I notice some of my ear hair growing longer, haha!

Keep this in mind next time someone says the treble is too hot or too weak... it might not be their preferences, hearing damage, or psychoacoustics, it could just be their different physiology (at least partially).
This also applies to harmonics, not just the reinforcement of a fundamental tone

https://testhifi.com/2019/08/09/fla...rally-weighted-intermodulation-disconsonance/

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.497.2126&rep=rep1&type=pdf

So yea some of the difference in how we hear is partially due to physiology! An @jude it's awesome to see you guys are yet again pushing the standard for headphone measurements! It'll be great to see the new measurements off this system
 
     Share This Post       
post-15793351
Post #41 of 42
Joined
Jun 20, 2001
Messages
10,883
Reaction score
4,602
It's been busy at Head-Fi HQ, but I am still working on Part 2 of the article, and will post it as soon as I can, and it will of course include more measurements.

On the topic of doing headphone measurements: So that we could fit the Brüel & Kjær 5128 into the isolation enclosure with the 45CA, we reconfigured the 5128-C into a 5128-B for now (using the Brüel & Kjær UA-2180 support foot). On the full torso only one fixture or the other can fit on the pneumatic platform inside the enclosure -- but with the disembodied 5128, both fixtures fit on it.

bruel-kjaer-5128-with-gras-45ca-in-herzan-cabinet_DSC04311.jpg
Fig.1: Brüel & Kjær 5128-B (using UA-2180 support foot) with the GRAS 45CA


Again, there will be more measurements in Part 2. And after it's posted we will thereafter be posting measurements regularly (we'll try posting them weekly to start). We have many 5128 measurements dating back to last December (though there weren't many performed during our lockdowns here in Michigan between March and June), and hundreds of measurements from the 45CA over the years.

Also related to doing headphone measurements: When we've done headphone measurements with visiting industry guests, they'll regularly comment about the measurement notes we log in our Audio Precision APx projects. One headphone engineer I recently screen-shared with in a video call suggested we post examples of these on the forums, thinking a few of you may find these interesting, too.

Here's an example of measurement notes for IEMs (Fig.2 below). Each line represents one sweep (from which many measurements can be derived). Each seating is noted, and we usually run at least two sweeps per seating. We record which fixture was used, whether the measurement was uncompensated or compensated, the voltage level, who did the seating, which ear tips were used, and any other noteworthy things.
audio-precision-apx-measurement-project-notes-IE.jpg
Fig.2: Screen shot of some of the measurement notes for IEM measurements


When we do AE/OE (around-ear/on-ear) measurements (Fig.3 below), we also note anything worthy of mention about position over the ears, headband size setting in clicks away from the smallest setting if the headband sizer has detents (or in estimated distance if it doesn't).

NOTE: I previously discussed how headband size settings can affect sensitivity, with measured examples: Measuring headphone sensitivity
audio-precision-apx-measurement-project-notes-AE-OE.JPG
Fig.3: Screen shot of some of the measurement notes for AE/OE (around-ear/on-ear) headphone measurements


As you can imagine, these project notes definitely come in handy.

Again, I'll be posting Part 2 as soon as I can, and then regular measurements thereafter. Thanks for your patience, everyone.
 
Last edited:
post-15794902
Post #42 of 42

jwbrent

Headphoneus Supremus
Joined
Nov 2, 2008
Messages
3,820
Reaction score
1,358
Location
California
Joined
Nov 2, 2008
Location
California
Posts
3,820
Likes
1,358
It's been busy at Head-Fi HQ, but I am still working on Part 2 of the article, and will post it as soon as I can, and it will of course include more measurements.

On the topic of doing headphone measurements: So that we could fit the Brüel & Kjær 5128 into the isolation enclosure with the 45CA, we reconfigured the 5128-C into a 5128-B for now (using the Brüel & Kjær UA-2180 support foot). On the full torso only one fixture or the other can fit on the pneumatic platform inside the enclosure -- but with the disembodied 5128, both fixtures fit on it.

Fig.1: Brüel & Kjær 5128-B (using UA-2180 support foot) with the GRAS 45CA


Again, there will be more measurements in Part 2. And after it's posted we will thereafter be posting measurements regularly (we'll try posting them weekly to start). We have many 5128 measurements dating back to last December (though there weren't many performed during our lockdowns here in Michigan between March and June), and hundreds of measurements from the 45CA over the years.

Also related to doing headphone measurements: When we've done headphone measurements with visiting industry guests, they'll regularly comment about the measurement notes we log in our Audio Precision APx projects. One headphone engineer I recently screen-shared with in a video call suggested we post examples of these on the forums, thinking a few of you may find these interesting, too.

Here's an example of measurement notes for IEMs (Fig.2 below). Each line represents one sweep (from which many measurements can be derived). Each seating is noted, and we usually run at least two sweeps per seating. We record which fixture was used, whether the measurement was uncompensated or compensated, the voltage level, who did the seating, which ear tips were used, and any other noteworthy things.
Fig.2: Screen shot of some of the measurement notes for IEM measurements


When we do AE/OE (around-ear/on-ear) measurements (Fig.3 below), we also note anything worthy of mention about position over the ears, headband size setting in clicks away from the smallest setting if the headband sizer has detents (or in estimated distance if it doesn't).

NOTE: I previously discussed how headband size settings can affect sensitivity, with measured examples: Measuring headphone sensitivity
Fig.3: Screen shot of some of the measurement notes for AE/OE (around-ear/on-ear) headphone measurements


As you can imagine, these project notes definitely come in handy.

Again, I'll be posting Part 2 as soon as I can, and then regular measurements thereafter. Thanks for your patience, everyone.
Having pre-ordered an EE Odin, I’m looking forward to seeing a graph with the new measurement method.
 
     Share This Post       

Users Who Are Viewing This Thread (Users: 1, Guests: 5)

  • Top