[jude]

Now wait a minute. We need more help as we go out to buy glasses. Does wood or steel make a difference over plastic? What lenses are being used? Does it make a difference if they are sunglasses?

Haha I know this is so weird. But it really does make a difference. Try it for yourself!

Actually, it really can make a difference. One of my primary considerations when buying eyeglasses is choosing a set with temples (the arms) that are as low-profile as possible, to eliminate or minimize the impact on the headphone seal.

The glasses I'm wearing now (one of the temples of which is pictured below) has no impact that I can on the bass with the HD820 -- it sounds exactly the same to me with or without these on. The temples (the arms) are very thin and are quite snug with my head. The curved portion is covered with a very thin rubber piece, and the back part of the curve was also shaped to fit perfectly against the area behind each ear.

Given that the HD820 is a closed-back headphone, how well it seals (or doesn't seal) against the wearer's head will have a greater impact than with its open-back siblings.

 

[AppleheadMay]

Actually, it really can make a difference. One of my primary considerations when buying eyeglasses is choosing a set with temples (the arms) that are as low-profile as possible, to eliminate or minimize the impact on the headphone seal.

The glasses I'm wearing now (one of the temples of which is pictured below) has no impact that I can on the bass with the HD820 -- it sounds exactly the same to me with or without these on. The temples (the arms) are very thin and are quite snug with my head. The curved portion is covered with a very thin rubber piece, and the back part of the curve was also shaped to fit perfectly against the area behind each ear.

Given that the HD820 is a closed-back headphone, how well it seals (or doesn't seal) against the wearer's head will have a greater impact than with its open-back counterparts.

I can't say I choose my glasses with regards to headphone use but I have similar needs because I ride motorbikes and need to wear my glasses under a helmet.
If the arms aren't superthin it can be quite painful behind the ears and difficult to slide them into the helmet as you have to put on the helmet first.
That's why I use these glasses:
https://lindberg.com/en/showroom/men/horn
Very thin and quite flexible metal yet strong arms.

 

[up late]

looking forward to seeing @jude's hd820 measurements

 

[jude]

I can't say I choose my glasses with regards to headphone use but I have similar needs because I ride motorbikes and need to wear my glasses under a helmet.
If the arms aren't superthin it can be quite painful behind the ears and difficult to slide them into the helmet as you have to put on the helmet first.
That's why I use these glasses:
https://lindberg.com/en/showroom/men/horn
Very thin and quite flexible metal yet strong arms.

Yes, that's the same maker of my eyeglasses in the photo (in my previous post).

 

[AppleheadMay]

Yes, that's the same maker of my eyeglasses in the photo (in my previous post).

Heh, I didn't notice that and didn't pay attention to it in your videos as well.
Maybe because I'm so used to mine having round glasses.
In any case, they're a very good brand for both motorcycling and headphone use.

 

[jude]

looking forward to seeing @jude's hd820 measurements

Here is the frequency response measurement of the Sennheiser HD820 versus its open-back siblings (Fig.1):

Fig.1 Sennheiser HD820 frequency response, compared to the Sennheiser HD800 and HD800S

As you can see, this is quite different than the measurement posted earlier in the thread by someone else. I suspect that the previously posted measurement did not model a proper acoustical load with an ear simulator/coupler -- an apparatus that connects the DUT (device under test) to a microphone in such a way that the working load on the DUT is the same as if used on a real ear [1]. Modeling the input impedance of the human ear becomes increasingly important the higher the acoustic output impedance of the DUT [1]. Also, the need for modeling the correct impedance increases with the proximity of the DUT to the ear [2]. It is for these reasons we use ear simulators for measuring headphones.

I should also note that we are currently using a new GRAS High Resolution Ear Simulator (GRAS RA0401), released in 2017, with key improvements versus a standard IEC 60318-4 ear simulator. The standard IEC 60318-4 (former IEC 60711) ear simulator was designed in the early 1980's and mimics the input and transfer impedance of a human ear. While the input impedance was based on measurements on human subjects, the transfer impedance was based on the assumption that the ear canal is a simple cylindrical volume with a hard termination. The new GRAS High Resolution Ear Simulator still complies with the IEC 60318-4 tolerance band (which is specified up to 10 kHz), but with significantly improved performance above 10 kHz. From 10 kHz to 20 kHz the transfer impedance is within +/- 2.2 dB, resulting in much improved repeatability and more realistic THD measurements [3].

We are also using a new, more human-like anthropometric measurement pinna by GRAS. The new pinna is based on 300+ 3D scans of human ear canals, designed to be closer to the human ear, with important changes to the pinna, concha and ear canal (versus previous measurement pinnae). You can see a short video about this here: GRAS Anthropometric Pinna

You can find out more about the measurement lab at Head-Fi HQ at the following link: Head-Fi Audio Measurement Lab

While the HD820 frequency response measurement is quite different versus the comparatively more linear frequency responses of its open-back siblings (HD800 and HD800S), a comparison with another premium closed-back headphone (like the Sony MDR-Z1R) might be a more relevant apples-to-apples comparison, and shows the HD820 in a different light (Fig.2):

Fig.2 Sennheiser HD820 frequency response, compared to the Sony MDR-Z1R

The steep drop that starts <200 Hz is there by design. If you want to better understand why it's there, make sure to watch this presentation by Axel Grell of Sennheiser from CanJam NYC 2018 (for discussion of this specifically, start watching at around the 27:00 mark):



Simply put, there was significant consideration given to an internally developed preference curve and psychoacoustics in voicing the HD820 (and Axel Grell does discuss other preference curves when asked about them in the talk above). If you haven't already done so, I strongly suggest you watch the entire presentation.

Given that it's a closed-back headphone, the HD820 will be more sensitive to breaks in the seal than its open-back siblings, but that's to be expected. As I said in an earlier post, I get a good seal with the HD820, even with my eyeglasses on.

As I also said earlier, I definitely prefer the HD820's tonal balance to the HD800S (and, for further reference, I strongly prefer the HD800S to the HD800). That said -- and this shouldn't be at all surprising -- the HD800S is, to my ears, ultimately more resolving. Again, the HD800S is open-back, free-breathing, unencumbered by some of the issues of acoustics/physics that must be dealt with for this class of closed-back headphone with the HD820. What resolution the HD820 does sacrifice to its sibling, though, is worth the gains in the tonal balance for me. Still, the HD820 is without a doubt one of the most resolving closed-back headphones currently available, and also among the widest imaging of them.

By the way, here are the THD measurements, first versus its HD800 and HD800S siblings (Fig.3), and then versus the Sony MDR-Z1R (Fig.4):

Fig.3 Sennheiser HD820 total harmonic distortion (THD), compared to the Sennheiser HD800 and HD800S

Fig.4 Sennheiser HD820 total harmonic distortion (THD), compared to the Sony MDR-Z1R

The measurements included in this post were made on the same day using:

• GRAS 45CA Headphone Test Fixture with:
  • GRAS RA0401 High Resolution Ear Simulators
  • GRAS KB5010/KB5011 Anthropometric Pinnae for 45CA
• Audio Precision APx555 Audio Analyzer
• Audio Precision APx1701 Transducer Test Interface
• Herzan custom acoustic and vibration isolation enclosure

[1] Brüel, P. V., Frederiksen, E., Mathiasen, H., Rasmussen, G., and Sigh, E. (1976). "Investigations of a new insert earphone coupler," Part I in "Impedance of Real and Artificial Ears," Brüel and Kjær report.

[2] Brüel & Kjær, "Measuring Human Audio Perception," presented at the 2018 ALMA International Symposium & Expo (AISE).

[3] Wille, M. (2017). "High Resolution Ear Simulator," GRAS Sound & Vibration white paper.

 

[GREQ]

Having auditioned the HD820 only 2 days ago for the first time, I have to say that my impression of the sound doesn't match the posted graphs.
Graphs show a bassier headphone compared to HD800/800S, but my ears thought it to be inversely true.
To my ears, HD820 was very mid-centric, and very dry sounding.

There seems to be some talk going around of extremely varying impressions on the perceived frequency response, which is due to individual head shape and wearing position.
I might have to re-audition and wear it in weird places.

 

[crinacle]

The graph looks very representative to me. I found it rather weird during my initial listening session as it was somehow simultaneously thick sounding and thin sounding at the same time. Bass was rather bloaty and slow and yet the vocals felt as if the singers were constantly using head voice. The enhanced bass and suppressed lower midrange seems to explain what I was hearing just fine.

 

[Virtu Fortuna]

The graph looks very representative to me. I found it rather weird during my initial listening session as it was somehow simultaneously thick sounding and thin sounding at the same time. Bass was rather bloaty and slow and yet the vocals felt as if the singers were constantly using head voice. The enhanced bass and suppressed lower midrange seems to explain what I was hearing just fine.

There's a significant drop on lower mid range on the graph indeed.

 

[Whitigir]

I don’t know, but looking through that graph, I automatically think of what a great job Z1R had done

 

[up late]

There's a significant drop on lower mid range on the graph indeed.

it's apparent in the other set of measurements as well, tho it looks more extreme there. it's an uneven fr no matter how you slice it.

 

[QueueCumber]

Here is the frequency response measurement of the Sennheiser HD820 versus its open-back siblings (Fig.1):


Fig.1 Sennheiser HD820 frequency response, compared to the Sennheiser HD800 and HD800S

As you can see, this is quite different than the measurement posted earlier in the thread by someone else. I suspect that the previously posted measurement did not model a proper acoustical load with an ear simulator/coupler -- an apparatus that connects the DUT (device under test) to a microphone in such a way that the working load on the DUT is the same as if used on a real ear [1]. Modeling the input impedance of the human ear becomes increasingly important the higher the acoustic output impedance of the DUT [1]. Also, the need for modeling the correct impedance increases with the proximity of the DUT to the ear [2], which is why we use ear simulators for measuring headphones.

I should also note that we are currently using a newer GRAS High Resolution Ear Simulator (GRAS RA0401). The standard IEC 60318-4 (former IEC 60711) ear simulator was designed in the early 1980's and mimics the input and transfer impedance of a human ear. While the input impedance was based on measurements on human subjects, the transfer impedance was based on the assumption that the ear canal is a simple cylindrical volume with a hard termination. While the GRAS High Resolution Ear Simulator still complies with IEC 60318-4 tolerance band (which is specified up to 10 kHz), it has improved performance above 10 kHz. From 10 Hz to 20 kHz the transfer impedance is within +/- 2.2 dB, resulting in much improved repeatability and more realistic THD measurements [3].

You can find out more about the measurement lab at Head-Fi HQ at the following link: Head-Fi Audio Measurement Lab

While the HD820 measurement may look rather unusual versus the comparatively very linear frequency responses of its open-back siblings (HD800 and HD800S), a comparison with another premium closed-back headphone (the Sony MDR-Z1R) shows it in a different light (Fig.2):


Fig.2 Sennheiser HD820 frequency response, compared to the Sony MDR-Z1R

The steep drop that starts <200 Hz is there by design. If you want to better understand why it's there, make sure to watch this presentation by Axel Grell of Sennheiser from CanJam NYC 2018 (for discussion of this specifically, start watching at around the 27:00 mark):



Simply put, there was significant consideration given to an internally developed preference curve and psychoacoustics in voicing the HD820 (and Axel Grell does discuss other preference curves when asked about them in the talk above). If you haven't already done so, I strongly suggest you watch the entire presentation.

Given that it's a closed-back headphone, the HD820 will be more sensitive to breaks in the seal than its open-back siblings, but that's to be expected. As I said in an earlier post, I get a good seal with the HD820, even with my eyeglasses on.

As I also said earlier, I definitely prefer the HD820's tonal balance to the HD800S (and, for further reference, I strongly prefer the HD800S to the HD800). That said -- and this shouldn't be at all surprising -- the HD800S is, to my ears, ultimately more resolving. Again, the HD800S is open-back, free-breathing, unencumbered by some of the issues of acoustics/physics that must be dealt with for this class of closed-back headphone with the HD820. What resolution the HD820 does sacrifice to its sibling, though, is worth the gains in the tonal balance for me. Still, the HD820 is without a doubt one of the most resolving closed-back headphones currently available, and also among the widest imaging of them.

By the way, here are the THD measurements, first versus its HD800 and HD800S siblings (Fig.3), and then versus the Sony MDR-Z1R (Fig.4):


Fig.3 Sennheiser HD820 total harmonic distortion (THD), compared to the Sennheiser HD800 and HD800S

Fig.4 Sennheiser HD820 total harmonic distortion (THD), compared to the Sony MDR-Z1R

The measurements included in this post were made on the same day using:

• GRAS 45CA Headphone Test Fixture with:
  • GRAS RA0401 High Resolution Ear Simulators
  • GRAS KB5010/KB5011 Anthropometric Pinnae for 45CA
• Audio Precision APx555 Audio Analyzer
• Audio Precision APx1701 Transducer Test Interface
• Herzan custom acoustic and vibration isolation enclosure

[1] Brüel, P. V., Frederiksen, E., Mathiasen, H., Rasmussen, G., and Sigh, E. (1976). "Investigations of a new insert earphone coupler," Part I in "Impedance of Real and Artificial Ears," Brüel and Kjær report.

[2] Brüel & Kjær, "Measuring Human Audio Perception," presented at the 2018 ALMA International Symposium & Expo (AISE).

[3] Wille, M. (2017). "High Resolution Ear Simulator," GRAS Sound & Vibration white paper.

How does the 820 compare with the Z1R for you, if you don’t mind making the comparison?

 

[GREQ]

it's apparent in the other set of measurements as well, tho it looks more extreme there. it's an uneven fr no matter how you slice it.

It's nothing new though, and certainly not a bad thing.
This kind of dip between 200-300Hz can be found in other well loved headphones like DT770 and HA-DX1000.
Usually I find this kind of response curve to be very pleasing, as it has the effect of reducing the thickness in the bass and still produces a textured low-bass response with impact.

 

[Rchandra]

Here is the frequency response measurement of the Sennheiser HD820 versus its open-back siblings (Fig.1):


Fig.1 Sennheiser HD820 frequency response, compared to the Sennheiser HD800 and HD800S

As you can see, this is quite different than the measurement posted earlier in the thread by someone else. I suspect that the previously posted measurement did not model a proper acoustical load with an ear simulator/coupler -- an apparatus that connects the DUT (device under test) to a microphone in such a way that the working load on the DUT is the same as if used on a real ear [1]. Modeling the input impedance of the human ear becomes increasingly important the higher the acoustic output impedance of the DUT [1]. Also, the need for modeling the correct impedance increases with the proximity of the DUT to the ear [2], which is why we use ear simulators for measuring headphones.

I should also note that we are currently using a newer GRAS High Resolution Ear Simulator (GRAS RA0401). The standard IEC 60318-4 (former IEC 60711) ear simulator was designed in the early 1980's and mimics the input and transfer impedance of a human ear. While the input impedance was based on measurements on human subjects, the transfer impedance was based on the assumption that the ear canal is a simple cylindrical volume with a hard termination. While the GRAS High Resolution Ear Simulator still complies with IEC 60318-4 tolerance band (which is specified up to 10 kHz), it has improved performance above 10 kHz. From 10 Hz to 20 kHz the transfer impedance is within +/- 2.2 dB, resulting in much improved repeatability and more realistic THD measurements [3].

You can find out more about the measurement lab at Head-Fi HQ at the following link: Head-Fi Audio Measurement Lab

While the HD820 measurement may look rather unusual versus the comparatively very linear frequency responses of its open-back siblings (HD800 and HD800S), a comparison with another premium closed-back headphone (the Sony MDR-Z1R) shows it in a different light (Fig.2):


Fig.2 Sennheiser HD820 frequency response, compared to the Sony MDR-Z1R

The steep drop that starts <200 Hz is there by design. If you want to better understand why it's there, make sure to watch this presentation by Axel Grell of Sennheiser from CanJam NYC 2018 (for discussion of this specifically, start watching at around the 27:00 mark):



Simply put, there was significant consideration given to an internally developed preference curve and psychoacoustics in voicing the HD820 (and Axel Grell does discuss other preference curves when asked about them in the talk above). If you haven't already done so, I strongly suggest you watch the entire presentation.

Given that it's a closed-back headphone, the HD820 will be more sensitive to breaks in the seal than its open-back siblings, but that's to be expected. As I said in an earlier post, I get a good seal with the HD820, even with my eyeglasses on.

As I also said earlier, I definitely prefer the HD820's tonal balance to the HD800S (and, for further reference, I strongly prefer the HD800S to the HD800). That said -- and this shouldn't be at all surprising -- the HD800S is, to my ears, ultimately more resolving. Again, the HD800S is open-back, free-breathing, unencumbered by some of the issues of acoustics/physics that must be dealt with for this class of closed-back headphone with the HD820. What resolution the HD820 does sacrifice to its sibling, though, is worth the gains in the tonal balance for me. Still, the HD820 is without a doubt one of the most resolving closed-back headphones currently available, and also among the widest imaging of them.

By the way, here are the THD measurements, first versus its HD800 and HD800S siblings (Fig.3), and then versus the Sony MDR-Z1R (Fig.4):


Fig.3 Sennheiser HD820 total harmonic distortion (THD), compared to the Sennheiser HD800 and HD800S

Fig.4 Sennheiser HD820 total harmonic distortion (THD), compared to the Sony MDR-Z1R

The measurements included in this post were made on the same day using:

• GRAS 45CA Headphone Test Fixture with:
  • GRAS RA0401 High Resolution Ear Simulators
  • GRAS KB5010/KB5011 Anthropometric Pinnae for 45CA
• Audio Precision APx555 Audio Analyzer
• Audio Precision APx1701 Transducer Test Interface
• Herzan custom acoustic and vibration isolation enclosure

[1] Brüel, P. V., Frederiksen, E., Mathiasen, H., Rasmussen, G., and Sigh, E. (1976). "Investigations of a new insert earphone coupler," Part I in "Impedance of Real and Artificial Ears," Brüel and Kjær report.

[2] Brüel & Kjær, "Measuring Human Audio Perception," presented at the 2018 ALMA International Symposium & Expo (AISE).

[3] Wille, M. (2017). "High Resolution Ear Simulator," GRAS Sound & Vibration white paper.

Judge when you say resolving what do you mean over tonal balance is one more "clearer" sounding while one is more has more harmony to the music

 

[up late]

It's nothing new though, and certainly not a bad thing.
This kind of dip between 200-300Hz can be found in other well loved headphones like DT770 and HA-DX1000.
Usually I find this kind of response curve to be very pleasing, as it has the effect of reducing the thickness in the bass and still produces a textured low-bass response with impact.

sure and i look forward to hearing the hd820 for myself