Consensus on the best mid-fi Hifiman to get these days?

[Jose Hidalgo]

What version are your Sundara's? I have bought my Sundara's very recently and have the HD6XX since last year.

My Sundaras are just like yours. There are only two versions of the Sundara: the original one, and the 2020 silent earpad revision that was introduced about 18 months ago. That revision didn't change anything driver-related: it was just new earpads with variable thickness which solved the small treble problem that previous version had. Which made the 2020 revision almost neutral, as shown by measurements. Only a soft 2 dB peak around 1000 Hz and a 3 dB peak around 6500 Hz, nothing more.

I've tested with slow sweeps and I get good extension down to 20Hz on my head with the Sundara's (no EQ) but not with the HD6XX.

The frequency plots of both the Sundara and the HD 600 by Oratory, made with professional equipment (GRAS 45), are self-explanatory.

• The un-EQed HD 600 reproduces 20 Hz @ -9.5 dB relatively to the usual Harman AE-OE 2018 target curve, as shown here.
• The un-EQed Sundara reproduces 20 Hz @ -10 dB relatively to the usual Harman AE-OE 2018 target curve, as shown here.
• The HD 6XX has little to do with the HD 600 since it's a cheaper clone of the HD 650. Still, it also reproduces 20 Hz @ -9.5 dB as shown here.

This can't be subject to debate, sorry. We are on ASR after all. Ask Oratory if you want.

Soundstage on the Sundara is indeed bigger than on the HD6XX (seems to be the same on all HD6xx series headphones).
I would rate the sound on both exactly the opposite as you rate them. Sundara sound more open and lively. That doesn't mean I don't love my HD6XX. It just more closed in, cozy and warm sounding.
My choice: On a budget = HD6XX, can spend more = Sundara

The 6XX has a slightly warmer sound out of the box (as shown once again by measurements) which makes it harder to compare with a neutral headphone like the Sundara. The HD 600 and the Sundara are easier to compare. Even more when EQed, which is my point here.

You are free to have your own subjective impressions and prefer the Sundara. That's great. The only thing you can't do is go against measurements and say that the un-EQed Sundara have "good extension down to 20 Hz". That is just not true, sorry. You can also find them comfortable for your head, good for you, but you can't dismiss the fact that they're 372g while the Senns are 260g. Those are just facts.

Last but not least, don't forget that you've just had your Sundaras, so you can easily suffer from recent buyer bias. The newest headphone is always the best, right ? I've had mine for almost a year, and during that time I've gone through several stages ("love them"... "love them less"... "love them more"...) in order to assess all that was right with them (which is a lot) and all that was wrong with them (which is little).

Both the Sundara and the HD 600 are excellent choices, and in the end it's a matter of personal preference. Only the measurements are unquestionable, and the fact that EQing them brings out the best in them and makes them much better.

 

[RHO]

The frequency plots of both the Sundara and the HD 600 by Oratory, made with professional equipment (GRAS 45), are self-explanatory.

• The un-EQed HD 600 reproduces 20 Hz @ -9.5 dB relatively to the usual Harman AE-OE 2018 target curve, as shown here.
• The un-EQed Sundara reproduces 20 Hz @ -10 dB relatively to the usual Harman AE-OE 2018 target curve, as shown here.
• The HD 6XX has little to do with the HD 600 since it's a cheaper clone of the HD 650. Still, it also reproduces 20 Hz @ -9.5 dB as shown here.

This can't be subject to debate, sorry. We are on ASR after all. Ask Oratory if you want.

You must be new here.
The accuracy and reliability of headphone-measurements are not open for debate? Really?

On my head the Sundara extends clearly way better down to 20Hz than the HD6XX. Others have done in ear measurements showing the same thing.
I don't get the bass shelf like the Aeon RT closed, but more like a flat extension as in the optimum hifi curve.
You have measurements done on some measurement rigs. Some more conforming to the one used in the Harman research, some less so. These measurements are very useful. Specifically those done on comparable rigs.
But accuracy is far from what you would see from measurements on electronics or even loudspeakers.
So, why the sundara performs different on a real head compared to on a synthetic head functioning as a measurement rig, I don't know.
But judging from the clearly audible difference between the HD6XX and Sundara in the lower octaves there is something going on.
Maybe variance from headphone to headphone? Specifically with Hifiman, I would not be surprised.

 

[Skinner001]

For what it's worth, I also have the Sundaras and without EQ they are a bit lacking in the very low end, for example, compared to 560s it's nearly night and day. I do love them, the look, design, I personally find them comfortable (enough) and they are a bit more open - but bass light (which is usually fine with me considering my preferences).

 

[RHO]

For what it's worth, I also have the Sundaras and without EQ they are a bit lacking in the very low end, for example, compared to 560s it's nearly night and day. I do love them, the look, design, I personally find them comfortable (enough) and they are a bit more open - but bass light (which is usually fine with me considering my preferences).

Yeah, could be unit to unit variance. I don't know. I clearly hear less bass than with the Aeon RT, but much more than with the HD6XX. The 6XX has more mid-bass which could disguise a bit the lack of subbass. The sundara does not have that and could therefore sound a bit lean to you.

@Jose Hidalgo : My subjective comments can be deduced from the various measurements on the Sundara 2020 compared to the HD6XX/650. Between 5.5kHz and 9kHz it has a little more energy than between 2kHz and 5.5kHz, where the HD6XX has the opposite. (looking at the compensated to optimum hifi curves)
Hence my remark that the Sundara sounds more open and lively and the 6XX sounding more warm. Most probably it has something to do with the wider soundstage on the Sundara too. (in combination with the driver placement)

Oratory Grapher Headphones

Plot frequency response measurements from our database using Oratory Grapher Headphones

headphonedatabase.com

 

[Jose Hidalgo]

You must be new here.

Of course I am. I signed up before you and I have about double your posts. You were saying ?

The accuracy and reliability of headphone-measurements are not open for debate? Really?

Not so much when they are done by Oratory, since he's kind of the universal reference in headphone-land right now. Besides, it's part of his job. Anyway, you should deal with him personally. Go to his Reddit community and tell him that his measurements are open for debate. Show him your arguments and I'm sure he'll respond adequately and in a professional way.

On my head [...]

On your head and on your ears, with your ear canals and everything, you are free to feel and believe anything you want. Nobody will dispute that.

Yes, it could be unit to unit variance. Or anything else. Let's just remember that unit to unit variance can hardly make a HP better than its specs.
It could even be that you have a faulty 6XX that makes your Sundara seem to go lower, while none of them really do. Just kidding.
Or again, it could just be new buyer bias. Or alcohol. Never underestimate alcohol!
I don't know what it is, really. Good for you I guess ?

I won't be debating measurements, nor personal preferences. The OP is going for the HD 600 and it's an excellent choice. A Sundara would be great too (I recommended it in a previous post, check page 2 ). The rest is only a matter of personal preference.

For what it's worth, I also have the Sundaras and without EQ they are a bit lacking in the very low end

Of course. That's exactly what measurements show, and what any user of a non-EQed, non-faulty Sundara should feel. People can feel different things in the 3-5 KHz region, due to their own ear canal diameter, but in the bass region, we should all feel pretty much the same thing when comparing two headphones, unless we have faulty ears of course (which I'm not implying for RHO BTW, it's just for the sake of the argument).

 

[MayaTlab]

in the bass region, we should all feel pretty much the same thing when comparing two headphones, unless we have faulty ears of course (which I'm not implying for RHO BTW, it's just for the sake of the argument).

Frequency Response Consistency

Frequency Response Consistency describes the variations in a headphones' frequency response due to their fit on your head.

www.rtings.com

Headphones v1.3.1 - Graph Tool

www.rtings.com

Headphones v1.5 - Graph Tool

www.rtings.com

AES E-Library » Improved Measurement of Leakage Effects for Circum-Aural and Supra-Aural Headphones

Headphone leakage effects can have a profound effect on low frequency performance of headphones. A large survey, including over 2000 individual headphone measurements, was undertaken in order to compare leakage effects on test subjects and leakage effects of the same headphones measured on a...

www.aes.org

 

[Jose Hidalgo]

I'm not disagreeing with any of that. What you are describing are various things that can make a headphone sound worse : if the fit isn't ideal, if the seal isn't perfect so there's leakage, etc.. But I have yet to find things that can make a headphone sound better than intended and have a much lower bass extension that it's supposed to have. I'm not saying it's impossible, I'm just saking that it's unlikely / uncommon. Especially when RHO is saying that the Sundara's fit on his own head isn't ideal. Any hints on how a non-ideal fit could make a headphone sound better? No?...

(for the record, Oratory takes all that into account in his own measurements by making several measurements for every headphone, repositioning them every time - but I suppose all people here already know that, right ?)

Besides, we are not debating about RHO's particular headphones. If the OP gets a Sundara, he will undoubtedly hear what 99,9% of Sundara users hear : a lack of bass extension similar to the HD 600. That is just reality. And thankfully all that can be improved by EQ. There's nothing more to say, really.

 

[Svperstar]

Way late to this thread so probably too late but I have been listening to the Sennheiser family for almost 20 years now starting with the 580(same driver as the 600, exact same). Currently own the 580/58X/590/6XX.

I'm sitting here listening to the 58X in my office and IMO its your best bang for the buck Senn in that family. I have not heard the 560 so I can't comment but the 58X and the 6XX have way more in common then they do different. I am sure someone will bitterly disagree but everything in the family is 85-90% the same. The 58X is the cheapest option. At 150 ohm easiest to drive as well.

 

[RHO]

Of course I am. I signed up before you and I have about double your posts. You were saying ?

You took that seriously?
Sorry, I will add smileys in the future.

Not so much when they are done by Oratory, since he's kind of the universal reference in headphone-land right now. Besides, it's part of his job. Anyway, you should deal with him personally. Go to his Reddit community and tell him that his measurements are open for debate. Show him your arguments and I'm sure he'll respond adequately and in a professional way.

Why would I have to take this up with Oratory1990?
I know he does measurements. As do others. And yes he's quite reliable and I use his data to make decisions.
But it has also been shown by in ear measurements that the Sundara can have much better extension than his measurements on the GRAS rig show

On your head and on your ears, with your ear canals and everything, you are free to feel and believe anything you want. Nobody will dispute that.

That is the point. Measurements on headphones are not an exact representation of what people hear. You can not have a measurement rig that is exactly like every human ear on the planet. Most likely it is different from every human ear on the planet. It's an average/approximation.
Besides that, not every brain's interpretation of the input signal is exactly the same. There is variance.
Maybe I hear much more low end than other people because most of my headphones are bass-light and I mostly listen to headphones lately. These are all options.
But also the fact that in-ear measurements demonstrated that the sundara can have much more low end extension than other measurements show.

Yes, it could be unit to unit variance. Or anything else. Let's just remember that unit to unit variance can hardly make a HP better than its specs.
It could even be that you have a faulty 6XX that makes your Sundara seem to go lower, while none of them really do. Just kidding.
Or again, it could just be new buyer bias. Or alcohol. Never underestimate alcohol!
I don't know what it is, really. Good for you I guess ?

Well, I compared them to the Aeon RT closed and that one clearly has more bass than both the HD6XX and Sundara. So I do hear the difference between lacking extension, adequate extension and a bass shelf. I would put the Sundara in the adequate category.

Alcohol is not a factor in my case. I don't do alcohol, like any responsible adult should.

I won't be debating measurements, nor personal preferences. The OP is going for the HD 600 and it's an excellent choice. A Sundara would be great too (I recommended it in a previous post, check page 2 ). The rest is only a matter of personal preference.


Of course. That's exactly what measurements show, and what any user of a non-EQed, non-faulty Sundara should feel. People can feel different things in the 3-5 KHz region, due to their own ear canal diameter, but in the bass region, we should all feel pretty much the same thing when comparing two headphones, unless we have faulty ears of course (which I'm not implying for RHO BTW, it's just for the sake of the argument).

Why would the bass frequencies be different from other frequencies?
Try listening to headphones and just EQ out anything under 60Hz for a few weeks.
Then bring it back.
Everything will sound bass heavy. Although maybe any headphones you own do show a bass roll-off in Oratory's measurements.
It's not only the physical aspects. Every humans brain functions differently. Quite comparable to others, but not the same. There is variance.
Why do you think we see a preference for more bass in younger listeners and for less bass than average in older trained listeners? Purely physical differences between the listeners? I don't think so. But it can be a part of the impact.

 

[Jimbob54]

I'm not disagreeing with any of that. What you are describing are various things that can make a headphone sound worse : if the fit isn't ideal, if the seal isn't perfect so there's leakage, etc.. But I have yet to find things that can make a headphone sound better than intended and have a much lower bass extension that it's supposed to have. I'm not saying it's impossible, I'm just saking that it's unlikely / uncommon. Especially when RHO is saying that the Sundara's fit on his own head isn't ideal. Any hints on how a non-ideal fit could make a headphone sound better? No?...

(for the record, Oratory takes all that into account in his own measurements by making several measurements for every headphone, repositioning them every time - but I suppose all people here already know that, right ?)

Besides, we are not debating about RHO's particular headphones. If the OP gets a Sundara, he will undoubtedly hear what 99,9% of Sundara users hear : a lack of bass extension similar to the HD 600. That is just reality. And thankfully all that can be improved by EQ. There's nothing more to say, really.

Just a slight point but one which does kind of annoy me a little. You don't hear a lack of anything. And any headphone only lacks or has an abundance in relation to something else, or a target.

All your (and many others) views are in relation to the Harman target. Not debating the merits of any target, just pointing out everything is relative.

 

[RHO]

Especially when RHO is saying that the Sundara's fit on his own head isn't ideal

I never said it isn't ideal. I said I ahve to set it at the smallest setting and if it were bigger it would be too big. Like it is now I'm lucky it IS ideal. It's very comfortable and I get a very good seal. Luckily it has this small setting. Otherwise it wouldn't have the ideal setting for me and would be too big.

 

[Robbo99999]

@RHO + @Jose Hidalgo , you two folks talking about bass & Oratory's measurements - Oratory shows the best case for bass measurements, as in he confirms he has proper seal for the measurements he uses to represent the bass portion of the measurement, so I think we can be quite certain that Oratory is really never gonna be underrepresenting the bass for any given headphone. So I think we can be confident that the bass levels of the Sundara & HD6XX(650) are as follows:

The only point of dispute is how many samples has Oratory measured of the Sundara, and is @RHO's sample different due to sample to sample variation, but historically I think Hifiman are quite good with matching channels, etc, as I distinctly remember Oratory saying that unit to unit variation of Hifiman HE4XX was very low. I wouldn't expect the quite expensive Sundara to show poor unit to unit variation, so I think what we see in this graph is gonna be pretty darn reliable. You might end up with less bass when you wear the headphone if it doesn't fit on you properly, but I wouldn't really expect you'd get more bass than shown.

 

[Jose Hidalgo]

Not really discussing that matter anymore. I'm just pointing out some minor points.

Why would the bass frequencies be different from other frequencies?

It's the other way around. The question would be "why would the 3-5 KHz region be different?". And the answer would of course be "because of the ear canal resonance frequency, which depends on the ear canal internal diameter, which can vary a lot and is unique to every human being". If we leave that special region aside, human beings tend to feel all other frequencies in a similar way. Depending on the loudness of course, as shown by Fletcher-Munson, and more recently by ISO 226:2003.

Why do you think we see a preference for more bass in younger listeners and for less bass than average in older trained listeners? Purely physical differences between the listeners? I don't think so. But it can be a part of the impact.

Simply because of aging. With age we lose treble sensitivity, so we need more treble to be happy. That is well documented I guess.

Just a slight point but one which does kind of annoy me a little. You don't hear a lack of anything. And any headphone only lacks or has an abundance in relation to something else, or a target.

Indeed ! But I think you knew what I meant. Be nice to somebody who doesn't have english as his primary language (or try discussing in french or spanish, that will level the ground ). My point here was that 99.9% of Sundara or HD 600 users will notice (not "hear" : "notice") a lack of bass extension. Voilà !


As for Robbo, yes, exactly my point. Thanks for confirming it. Both the Sundara, the 650/6XX and the 600 are virtually identical in the bass region, and they all lack about 10 dB @ 20 Hz relatively to the Harman Target (or about 4.5 dB @ 20 Hz relatively to the Optimum HiFi target).

I'm not saying that RHO is dreaming, or crazy or anything. I'm just saying that there's definitely something going on in his personal case, and it's not normal. He can't say that the Sundara (as in "in general") have natural bass extension, because that would be wrong and it could induce people into wrong decisions. He can however say that according to his subjective impressions, his particular Sundara seem to have more bass extension than they normally should, for reasons unknown.

I too think that it's very unlikely that any Sundara gives so much bass extension (Oratory's graphs are pretty darn reliable, and I hardly believe in miracles). So I believe there's another explanation. Which one I don't know, and I don't really care since it seems to concern only one person. Ultimately what matters to me is that the OP can buy whatever he wants, being as well-informed as possible, like I was when I was in his position thanks to many nice people.

 

[shaney777]

Sounds like the headphones weren't driven properly. Was it with your Hifiman? Many planar magnetic drivers have low resistance and are more dependent on current than voltage to be driven properly. Could be that the IEMagni simply does not output enough current for your headphone while still being transparent in its signal processing.

It was the Hifiman, yes. Supposedly IEMagni has twice as much power as Atom, but I surely didn't notice it. Atom sounded much better. Current? It's all over my head haha. Both amps have been returned now.

 

[shaney777]

OK, I have to answer this. I've been owning both the HD 600 and the Sundara for almost a year now. Some of the previous comments don't take EQ into account. I do, because to me it changes everything for these two headphones (for any headphone actually). So nevermind all the non-EQed frequency plots, really. In this post, let's just assume that I'm talking about EQed headphones, unless I specifically say otherwise.

Both the HD 600 and the Sundara lack bass without EQ :

Spoiler: Without EQ

• HD 600 : roll-off below 110 Hz, reaching 58 Hz @ -3 dB
• Sundara : roll-off below 140 Hz, reaching 54 Hz @ -3 dB

A simple EQ via Oratory presets (included with my app) greatly enhances both of them :

Spoiler: With EQ

• EQed HD 600 : reaches 42,5 Hz @ 0 dB, and 30 Hz @ -2 dB, with a preamp gain of -5.5 dB
• EQed Sundara : reaches 63 Hz @ 0 dB, and 35 Hz @ -2 dB, with a preamp gain of -5.5 dB

But we can try to push things a little further.

Spoiler: Here's the juicy stuff

• For the HD 600, it can be a challenge to push bass even further, because of the risk of distortion, and even of driver degradation if you really listen at them very loudly. I would advise a bit of caution here. However I have successfully added an additional filter to their Oratory preset, with this simple EAPO code that anybody can try :
  GraphicEQ: 20 2.3; 30 2.3; 42 0; 20000 0
  The HD 600 then are able to reach 30 Hz @ 0 dB and 20 Hz @ -1.8 dB. Of course preamp gain needs to be adjusted from -5.5 dB to -7.8 dB.
  I was expecting distortion, but to my surprise I got nothing really disturbing. Only the subjective impression that we are reaching the limits of this headphone, which is normal after all. I guess it depends on how loud you listen to them, so if you remain reasonable, everything should be OK.
  
  
• For the Sundara, like Oratory states in his PDF, the 28 Hz parametric filter gain can be changed from 0.0 (no bass extension) to 7.0 dB (linear bass extension). In my experience, 2.0 dB seems like a good balance, plus this value was already used in Oratory's preliminary Sundara preset. This makes the Sundara reach 30 Hz @ 0 dB and 23 Hz @ -2 dB. Preamp gain needs to be adjusted accordingly, from -5.5 dB to -7.1 dB.

All this comes at a cost : greater preamp gains mean lower output volumes and possibly the need of a bigger amp.

But in my case it's just fine. I can drive both these headphones with my Topping L30 in medium (0 dB) position and volume knob always in the max position (as it should be according to John Yang, one of the L30 designers - I only use digital volume control within my player). And if I really want to crank it up, I can always put my L30 in high (+9 dB) position, which gives me 9 dB of headroom. That's more than I need with any of these headphones, so I'm perfectly happy. The L30 is such a tiny little beast, it's amazing !

Now on to the big question : HD 600 or Sundara ? which one do I prefer ?

Spoiler: Here's your answer !

... quite honestly, after almost a year of use, I would go for the HD 600. Here's why :

• First, the HD 600 are more comfortable than the Sundara. Some may think that comfort should be the last criteria. I too thought so some time ago. But now I have to digress. Comfort is of the utmost importance so your mind can really focus on music.
  --> The HD 600 are not "extremely" comfortable : they're basic, have a bit of clamping force and lack a proper suspension system (after all they're studio grade material, they need to be simple and unbreakable, lol). Both of my Nighthawks are infinitely more comfortable.
  --> But the Sundara are more uncomfortable than the HD 600, that's for sure. They're clearly heavier (372g vs. 260g) and feel so on your head. They're always "there". They're not suited for big heads or big ears (round pads), whereas the HD 600 are just fine in either case.
  
  
• Both the Sundara and the HD 600 are open back, which is a good thing because you don't get any internal reflections / resonances. The sound is clear and precise without any unwanted echo (my Nighthawks have a bit of that echo, which is bad on most songs and good on some of them - a nice side effect I guess).
  
  
• None of them (HD 600 or Sundara) can make it down to 20 Hz comfortably. The Nighthawks rule in that area, they just have no limits and no distortion so you get all that nice rumble to your ears. It's all there, and you can see that the drivers are comfortable with that, they don't even suffer. Of course when you get to the midrange and treble, they don't sound as good as the HD 600 or the Sundara. They sound "good" but not "natural". For example the guitars don't sound exactly like they should, where as with the HD 600 you get exactly the sound you're supposed to get.
  
  
• As for the soundstage, it's true : the HD 600 have a small, kind of "in your head" soundstage. It can be a problem to some people. To me it's not. It's actually one of the reasons why I wanted them. I wanted that intimate soundstage. But if I want to make it considerably bigger, I just press the "HeSuVi" button in my app, and voilà. Works beautifully with the HD 600.
  
  
• All in all, the Sundara sound is really nice, but is it nicer than the HD 600's ? After some extensive listening, I don't think so. The HD 600 bring that "magic touch" to guitars, strings and vocals. I can't explain how they do it, but the Sundara don't do quite as well. The Sundara are great, but the HD 600 are magic to my ears. I would have expected for the planar magnetic technology to make a little difference here, but to me it doesn't (so close though) and it just weights heavier.

To sum it up : comfort = HD 600 / Open back = both / Sound = HD 600 (but really close) / Sub-bass = none of them, but with EQ you can get down to decent levels, with no clear winner here / Soundstage = Sundara (but bigger doesn't necessarily mean better, it's a matter of taste).

So don't get me wrong : the Sundara are really great and probably worth their price. I just think that the HD 600 are even greater. It's amazing what Sennheiser was able to achieve back in 1997 (they haven't been modified since then, only aesthetically restyled). The HD 650 couldn't do better (only slightly different), and neither could the HD 660S. And now thanks to EQ we get to enjoy the HD 600 in all their glory, and it really makes a big difference on some pieces of music.

What an amazing pair of cans. @shaney777 , you are going to love them so much. Long live the king !

Beautiful response, thank you very much!! This is much more in line with the praise I've seen for HD 600 over the years. Regarding the L30, I wonder why the designer recommends the volume knob to be maxed? I have never heard of this. It's odd because, for example, Atom instructions are to near max out computer volume and use amp volume knob. I wonder if it makes any difference.

Slightly off subject, but I find it interesting that Tyll basically says the HE400S has dethroned HD 600. I never hear anyone talking about this headphone, but he seems to adore it.

 

[Jimbob54]

Indeed ! But I think you knew what I meant. Be nice to somebody who doesn't have english as his primary language (or try discussing in french or spanish, that will level the ground ). My point here was that 99.9% of Sundara or HD 600 users will notice (not "hear" : "notice") a lack of bass extension. Voilà !

Wasnt a dig at the phrasing- more the point generally. If either of these are someones first decent headphone and they are not coming from a good speaker set up, they wont "notice" the lack of bass extension. You only notice it if you have experience of something that does have good bass extension. Witness the ocean of people who may only have experienced Beyer 990s thinking that is how music on a decent system is how it is meant to be. There is a tendency many of us fall into (because we have experienced "better") that stock headphones cant be enjoyed. Which for 99% of the world is a nonsense.

 

[Robbo99999]

Beautiful response, thank you very much!! This is much more in line with the praise I've seen for HD 600 over the years. Regarding the L30, I wonder why the designer recommends the volume knob to be maxed? I have never heard of this. It's odd because, for example, Atom instructions are to near max out computer volume and use amp volume knob. I wonder if it makes any difference.

Slightly off subject, but I find it interesting that Tyll basically says the HE400S has dethroned HD 600. I never hear anyone talking about this headphone, but he seems to adore it.

I think you're right in your understanding of how to use a headphone amp - best SINAD (& dynamic range) is achieved by running digital volume as close to maximum as possible and adjusting down the volume using the volume knob on the (analog) headphone amp. I have the Atom amp and essentially this is how I use it.

 

[RHO]

@RHO + @Jose Hidalgo , you two folks talking about bass & Oratory's measurements - Oratory shows the best case for bass measurements, as in he confirms he has proper seal for the measurements he uses to represent the bass portion of the measurement, so I think we can be quite certain that Oratory is really never gonna be underrepresenting the bass for any given headphone. So I think we can be confident that the bass levels of the Sundara & HD6XX(650) are as follows:
View attachment 156605
The only point of dispute is how many samples has Oratory measured of the Sundara, and is @RHO's sample different due to sample to sample variation, but historically I think Hifiman are quite good with matching channels, etc, as I distinctly remember Oratory saying that unit to unit variation of Hifiman HE4XX was very low. I wouldn't expect the quite expensive Sundara to show poor unit to unit variation, so I think what we see in this graph is gonna be pretty darn reliable. You might end up with less bass when you wear the headphone if it doesn't fit on you properly, but I wouldn't really expect you'd get more bass than shown.

Hifiman is also known to send out review samples that differ from current production samples.
And because they match channels very well, doesn't mean there isn't a big spread in sample to sample performance. You can still match L+R.
I'm not saying Oratory's measurements are wrong. I'm saying that there examples out there that have better bass extension than the one he shows in his measurements and mine could be one of them (I suspect so) and maybe it is consistent with the most recent production lots.

 

[RHO]

Simply because of aging. With age we lose treble sensitivity, so we need more treble to be happy. That is well documented I guess.

Does Harman take frequencies above 10kHz into account?
From what I got it was not only age related hearing loss that accounted for the preference of a lower bass shelf.

It's the other way around. The question would be "why would the 3-5 KHz region be different?". And the answer would of course be "because of the ear canal resonance frequency, which depends on the ear canal internal diameter, which can vary a lot and is unique to every human being". If we leave that special region aside, human beings tend to feel all other frequencies in a similar way. Depending on the loudness of course, as shown by Fletcher-Munson, and more recently by ISO 226:2003.

I see your point.
Well, I've tested it again today and heard the same thing. (Sundara vs HD6XX vs Aeon RT closed => slow freq sweep) Lets assume my Sundara differs from the ones Oratory got for his measurements.

 

[Jose Hidalgo]

Hifiman is also known to send out review samples that differ from current production samples.

... in a good way, not in a bad way.

Does Harman take frequencies above 10kHz into account?

I didn't talk about hearing loss at very high frequencies. I talked about losing treble sensitivity at the usual below 10 KHz frequencies. Unfortunately, age-related hearing loss (or rather "hearing degradation") isn't limited to very high frequencies. Hence the usual "I'm sorry, come again please ?" by many older people.

I think you're right in your understanding of how to use a headphone amp - best SINAD (& dynamic range) is achieved by running digital volume as close to maximum as possible and adjusting down the volume using the volume knob on the (analog) headphone amp. I have the Atom amp and essentially this is how I use it.

I too thought that, but the L30 designer seems to say otherwise for his amp. Turns out it's very handy that way! I love leaving the volume knob in max position and just adjusting digital volume from my keyboard. Here are John Yang's messages :

I'm sure no difference can be heard anyway. The L30 is a beast and its performance for any knob position is way beyond human hearing capability.