[ruinedx]

HD600 soundstage is VERY amp dependant. Pair it with a SS amp like the Schiit Jotunheim which has an inherently narrow and compressed soundstage and the HD600 produces a claustrophobic "inside the head" image. However, pair it with a good tube amp, or even a hybrid-tube amp like the Schiit Mjolnir 2, and the HD600 is transformed into a very open-sounding headphone with amazing space, decay and separation between instruments. The difference is pretty amazing. HD600 paired with a Schiit Mjolnir 2 fitted with Siemens PCC88 (1963) tubes or similar, plus a bit of low-end bass EQ boost, comes pretty close to an end-game combo IMO.

The problem is, if the headphones are *that* amp dependent to sound ideal then I consider it a serious weakness of the headphone. The HD800 has the same problem, extremely gear dependent. If I buy multiple $1000+ HPA/DAC units plus ones that cost less than that and still can't get a sound I'm even remotely happy with then I'm going to blame the headphone, not the gear. Maybe HD600 can have a good soundstage with just the right gear, and maybe HD800 can not have ear-piercing treble with just the right gear, but overall these seem to be weaknesses of these headphones that you can compensate for with very specific gear. The HD700 is a little picky, but for the most part it sounds great on most gear I've tried (even sounds excellent on LG smartphones that have the builtin headphone amp + ess sabre DACs, which is an impressive feat) - and HD820 seems quite gear agnostic so far as well - both of which I will therefore say are better headphone designs since they sound fantastic out of box to my ear on a wide variety of equipment instead of needing to be mated to a narrow selection of equipment (or require substantial EQ, or require user modification, etc) to sound ideal.

For the four headphones I owned that were on topic for this discussion - I A/B compared the HD700 to the HD600 on multiple HPA/DACs and the HD700 blew away the HD600's soundstage on all of the gear I tried. I also A/B compared the HD800 to the HD700 and A/B compared the HD820 to the HD700 again on same equip - both HD8xx models blew away the HD700's soundstage and from memory (was unable to A/B) the HD800 beat the HD820's soundstage - but the HD800 was far too aggressive in the treble to use in the long term (i found it physically painful) and was too lean in the bass, which HD820 solved on both fronts in my case and was worth sacrificing a bit of soundstage for (note, despite this the HD820 soundstage substantially beats the HD700's already-impressive soundstage from my testing). So I have settled on for music the HD700 + HD820 as my "go to" pair to use - selecting each depending on the use case - as soundstage is one of my top needs, if not top need, in selecting a headphone.

 

[bagwell359]

The problem is, if the headphones are *that* amp dependent to sound ideal then I consider it a serious weakness of the headphone. The HD800 has the same problem, extremely gear dependent. If I buy multiple $1000+ HPA/DAC units plus ones that cost less than that and still can't get a sound I'm even remotely happy with then I'm going to blame the headphone, not the gear. Maybe HD600 can have a good soundstage with just the right gear, and maybe HD800 can not have ear-piercing treble with just the right gear, but overall these seem to be weaknesses of these headphones that you can compensate for with very specific gear. The HD700 is a little picky, but for the most part it sounds great on most gear I've tried (even sounds excellent on LG smartphones that have the builtin headphone amp + ess sabre DACs, which is an impressive feat) - and HD820 seems quite gear agnostic so far as well - both of which I will therefore say are better headphone designs since they sound fantastic out of box to my ear on a wide variety of equipment instead of needing to be mated to a narrow selection of equipment (or require substantial EQ, or require user modification, etc) to sound ideal.

For the four headphones I owned that were on topic for this discussion - I A/B compared the HD700 to the HD600 on multiple HPA/DACs and the HD700 blew away the HD600's soundstage on all of the gear I tried. I also A/B compared the HD800 to the HD700 and A/B compared the HD820 to the HD700 again on same equip - both HD8xx models blew away the HD700's soundstage and from memory (was unable to A/B) the HD800 beat the HD820's soundstage - but the HD800 was far too aggressive in the treble to use in the long term (i found it physically painful) and was too lean in the bass, which HD820 solved on both fronts in my case and was worth sacrificing a bit of soundstage for (note, despite this the HD820 soundstage substantially beats the HD700's already-impressive soundstage from my testing). So I have settled on for music the HD700 + HD820 as my "go to" pair to use - selecting each depending on the use case - as soundstage is one of my top needs, if not top need, in selecting a headphone.

It's true that the HD-600 doesn't do soundstage that well, if that was the only or most important aspect of playback you might have a point. It's not.

The HD-600 is relevant because:

- it's very affordable
- it's very flat from 60 Hz up, continually showing up the 650, and everything Beyer, Grado, and others can come up with.
- it's very clear and tonally accurate - in particular with acoustic instruments, but not bound by just list.

The 800 is a moody piece of lab equipment. Equisite staging and detailing which can really get your attention, but a maddening lack of bass impact at that price, incorrect tonality - occasionally. Cold and hard as a diamond often times. Fatigue. How can a watershed can fatigue so? Well the HE-6 can be pretty fatiguing as well I guess.

 

[ruinedx]

It's true that the HD-600 doesn't do soundstage that well, if that was the only or most important aspect of playback you might have a point. It's not.

The HD-600 is relevant because:

- it's very affordable
- it's very flat from 60 Hz up, continually showing up the 650, and everything Beyer, Grado, and others can come up with.
- it's very clear and tonally accurate - in particular with acoustic instruments, but not bound by just list.

The 800 is a moody piece of lab equipment. Equisite staging and detailing which can really get your attention, but a maddening lack of bass impact at that price, incorrect tonality - occasionally. Cold and hard as a diamond often times. Fatigue. How can a watershed can fatigue so? Well the HE-6 can be pretty fatiguing as well I guess.

I'm not saying the HD600 is a bad headphone, its actually probably a good reference point to start with as a first "high end" headphone.

For me soundstage is probably the most important aspect of playback for a headphone, and I say that because if the soundstage isn't expansive I'd rather not listen to a headphone at all; Sennheiser's HD700/HD8xx got me back into listening to headphones after many years of speakers-only listening because of their soundstage. There are other aspects that are important too, of course, so I wouldn't want to listen to something that sounds like garbage just because it has a wide soundstage; but if the soundstage isn't wide, then I definitely won't consider the headphone as a "top pick." Hence my point is quite valid for others who value soundstage as much as I do.

Whether something is "flat" or not is of little concern to me. I used to have that concern maybe 25 years ago, but after a long time of listening to various audio equipment whether I like the way it sounds is more important. With a headphone especially, unless I were an audio mastering professional flatness I'd find as a disadvantage as "flat" sound does not emulate what we hear in our natural environments - and with no room surfaces to color the audio, in a headphone that means a non-flat curve will better approach more natural sound people are accustomed to hearing. And, this is another reason soundstage is hugely important, to get that reflected sound experience that sounds more natural like everyday environments than a typical headphone would.

 

[bagwell359]

I'm not saying the HD600 is a bad headphone, its actually probably a good reference point to start with as a first "high end" headphone.

For me soundstage is probably the most important aspect of playback for a headphone, and I say that because if the soundstage isn't expansive I'd rather not listen to a headphone at all; Sennheiser's HD700/HD8xx got me back into listening to headphones after many years of speakers-only listening because of their soundstage. There are other aspects that are important too, of course, so I wouldn't want to listen to something that sounds like garbage just because it has a wide soundstage; but if the soundstage isn't wide, then I definitely won't consider the headphone as a "top pick." Hence my point is quite valid for others who value soundstage as much as I do.

Whether something is "flat" or not is of little concern to me. I used to have that concern maybe 25 years ago, but after a long time of listening to various audio equipment whether I like the way it sounds is more important. With a headphone especially, unless I were an audio mastering professional flatness I'd find as a disadvantage as "flat" sound does not emulate what we hear in our natural environments - and with no room surfaces to color the audio, in a headphone that means a non-flat curve will better approach more natural sound people are accustomed to hearing. And, this is another reason soundstage is hugely important, to get that reflected sound experience that sounds more natural like everyday environments than a typical headphone would.

I mean flat not in an anechoic chamber, but considering human hearing within the ear - quite different than any room. When I was hip deep in high end speakers for 43 years I spent the last 35 of those years adjusting rooms to show speakers at their best, because if a speaker/room produces a 40 Hz note 8 db above norm, than its a coloration/annoyance and has to go if possible.

I disagree with the average room thesis of Oratory_1990 among others. My rooms were not average by design, and I don't give two figs about the desired bass output opinion they promote because a 25 year old listener that's a dedicated beats listener can say nothing to me that matters to me ew audio. I'm dedicated to what I heard at the BSO, Carnegie, or even a decent jazz venue and not some stadium with 4 stacks of Marshalls.

I disagree with your stand that speakers in rooms have very good soundstages. Most audiophiles stick a big metal rack with a pile of equpment right between the speakers - talk about killing center stage. Or put them on suspened wooden floors with no spikes. I've had speakers that throw a massive soundstage - ML CLS IIz, Verity Parsiafal, ProAc EBS, 2 pair MG-1, Duettas. You are not going to get that out of a headphone - you've got to translate to headphones.

If a headphone is far off flat - like say Beyer 770's it becomes fatiguing in short order. I love a wide and deep soundstage, which I get out of my modified and EQ'd HE-500, but the tonality of pianos and violins just don't cut it vs the 600. Not enough to be fatiguing, but enough than when I want it clear tonally (above 70 Hz) the 600 beats all my other headphones (see the Sig)

Basically everything matters if you are sensitive to it. I don't know how to think about a listener that focuses one one trait over all - like bass or soundstage. Can't say its wrong, but its not for me, and I believe many here.

 

[ruinedx]

I mean flat not in an anechoic chamber, but considering human hearing within the ear - quite different than any room. When I was hip deep in high end speakers for 43 years I spent the last 35 of those years adjusting rooms to show speakers at their best, because if a speaker/room produces a 40 Hz note 8 db above norm, than its a coloration/annoyance and has to go if possible.

I disagree with the average room thesis of Oratory_1990 among others. My rooms were not average by design, and I don't give two figs about the desired bass output opinion they promote because a 25 year old listener that's a dedicated beats listener can say nothing to me that matters to me ew audio. I'm dedicated to what I heard at the BSO, Carnegie, or even a decent jazz venue and not some stadium with 4 stacks of Marshalls.

I disagree with your stand that speakers in rooms have very good soundstages. Most audiophiles stick a big metal rack with a pile of equpment right between the speakers - talk about killing center stage. Or put them on suspened wooden floors with no spikes. I've had speakers that throw a massive soundstage - ML CLS IIz, Verity Parsiafal, ProAc EBS, 2 pair MG-1, Duettas. You are not going to get that out of a headphone - you've got to translate to headphones.

If a headphone is far off flat - like say Beyer 770's it becomes fatiguing in short order. I love a wide and deep soundstage, which I get out of my modified and EQ'd HE-500, but the tonality of pianos and violins just don't cut it vs the 600. Not enough to be fatiguing, but enough than when I want it clear tonally (above 70 Hz) the 600 beats all my other headphones (see the Sig)

Basically everything matters if you are sensitive to it. I don't know how to think about a listener that focuses one one trait over all - like bass or soundstage. Can't say its wrong, but its not for me, and I believe many here.

The problem is headphones introduce an artificial environment by design that is not found anywhere else in every day life. Therefore measuring them as if they were not an artificial environment (i.e. typical freq response measurement of headphones) is a flawed measurement system. Even your most treated room with speakers (again, unless an anechoic chamber) will have tons of dispersed and reflected sound arriving at different times that you will not typically get from a headphone.

When you hear a concert, you don't have the sound source placed 3" away from your eardrums. The sound waves are dispersed and reflected all over the room before it reaches your ear.

When you step outside and hear a dog bark, it is not barking directly into your ear. It is often in the distance, but even if its right in front of you the sound does not travel directly into your ear canal.

Headphones, on the other hand, basically beam sound directly into your ear canal which is contrary to how humans hear sound naturally. Therefore, to treat headphones as a reference device that should achieve an audibly flat response as if it was not an artificial environment is a highly flawed viewpoint IMO because the science to attempt to measure and quantify this is very much in its infancy, as proven by the vast majority of headphones (even using the Harman curve, etc) sounding unnatural with a flat, collapsed soundstage that does not represent real-world hearing of any type of sound. The Sennhesier HD8xx series (and HD7xx to a lesser extent) are the first headphones I've personally heard that approach a "real," natural sound - and that is namely because of their atypical (for a headphone) soundstage that emulates the way we hear sound naturally (or via speakers if you prefer). They are definitely on to something with this approach, hence why I have bought three headphones from this lineup - they betray the status quo "headphone sound" and instead present something less artificial and more real sounding. The HD800 definitely was flawed and too aggressive for me to listen to long term, but the HD820 I really love the balance they have struck between this lifelike sound and sound you can listen to for extended periods without fatigue; but the HD820 is huge, expensive, and requires a lot of power so the HD700 is a good compromise when the HD820 would not be appropriate. The HD600 on the other hand I found of very little interest as it sounded like just a better iteration of every other Sennhesier open back headphone I'd heard previously, as opposed to the lifelike sound of the HD700/HD8xx.

Note that developers of virtual reality audio subsystems have run into this same problem of typical headphones sounding closed in and artificial, with the source of sounds appearing inside ones head instead of where the sound should naturally be coming from. This has been tackled in a combination ways, both by 1) creating audio processing systems (ie THRIVE) to compensate for the headphones and 2) using headphone-like speakers that sit near the ear instead of on the ear to reproduce the sound (i.e. Oculus Quest, Valve Index). Either way, it became clear to VR audio designers that the standard headphone design was woefully inadequate to reproduce realistic sound, and it became clear that no amount of software processing could emulate real life sounds as well as a fundamental rethinking of headphone design - as Sennheiser seperately accomplished with the HD700/HD8xx.

 

[bagwell359]

The problem is headphones introduce an artificial environment by design that is not found anywhere else in every day life. Therefore measuring them as if they were not an artificial environment (i.e. typical freq response measurement of headphones) is a flawed measurement system. Even your most treated room with speakers (again, unless an anechoic chamber) will have tons of dispersed and reflected sound arriving at different times that you will not typically get from a headphone.

When you hear a concert, you don't have the sound source placed 3" away from your eardrums. The sound waves are dispersed and reflected all over the room before it reaches your ear.

When you step outside and hear a dog bark, it is not barking directly into your ear. It is often in the distance, but even if its right in front of you the sound does not travel directly into your ear canal.

Headphones, on the other hand, basically beam sound directly into your ear canal which is contrary to how humans hear sound naturally. Therefore, to treat headphones as a reference device that should achieve an audibly flat response as if it was not an artificial environment is a highly flawed viewpoint IMO because the science to attempt to measure and quantify this is very much in its infancy, as proven by the vast majority of headphones (even using the Harman curve, etc) sounding unnatural with a flat, collapsed soundstage that does not represent real-world hearing of any type of sound. The Sennhesier HD8xx series (and HD7xx to a lesser extent) are the first headphones I've personally heard that approach a "real," natural sound - and that is namely because of their atypical (for a headphone) soundstage that emulates the way we hear sound naturally (or via speakers if you prefer). They are definitely on to something with this approach, hence why I have bought three headphones from this lineup - they betray the status quo "headphone sound" and instead present something less artificial and more real sounding. The HD800 definitely was flawed and too aggressive for me to listen to long term, but the HD820 I really love the balance they have struck between this lifelike sound and sound you can listen to for extended periods without fatigue; but the HD820 is huge, expensive, and requires a lot of power so the HD700 is a good compromise when the HD820 would not be appropriate. The HD600 on the other hand I found of very little interest as it sounded like just a better iteration of every other Sennhesier open back headphone I'd heard previously, as opposed to the lifelike sound of the HD700/HD8xx.

Note that developers of virtual reality audio subsystems have run into this same problem of typical headphones sounding closed in and artificial, with the source of sounds appearing inside ones head instead of where the sound should naturally be coming from. This has been tackled in a combination ways, both by 1) creating audio processing systems (ie THRIVE) to compensate for the headphones and 2) using headphone-like speakers that sit near the ear instead of on the ear to reproduce the sound (i.e. Oculus Quest, Valve Index). Either way, it became clear to VR audio designers that the standard headphone design was woefully inadequate to reproduce realistic sound, and it became clear that no amount of software processing could emulate real life sounds as well as a fundamental rethinking of headphone design - as Sennheiser seperately accomplished with the HD700/HD8xx.

Actually the ear itself (not just what gets down the canal directly) has a lot to do with the sound also. I find closed headphones to have too many problems to believe in seriously as a source of reasonably accurate sound. Clearly speakers do better. I went from 5 excellent treated rooms over 45 years to a miserable cave, No speaker sounds good in there.

Open cans have the advantage of having less reflected sound, I do mods to my cans to have even less. I use EQ too - not to get absolute flat but to get rid of instances of extreme dips and rises - many headphones have +/- 15 db changes between 10 kHz and 20 kHz, and need bass correction to cans such as the HD-800S, of course there is nothing to be done about the extra HD added into the 800S to mimic more bass by the designers. Speaking of the 800S I think the Voce, 007, 009, Arya, E2 are either more accurate, more listenable or both. 800S is pretty edgy on transistors, another story on some tubes. I do believe "lab equipment with the power to amaze and to drive one crazy" fits them well. The 700? V-shaped failure with a nice soundstage (or headstage if you prefer) - according to the sales figures. What are they working on now? Mighty quiet the past few years.

I have no idea what they were using with virtual audio designs/testing - but my modded HE-500 (bought for $365) routinely throw images far off the head. I guess I'm lucky after a pile of $5-20k speakers behind me I'm able to buy the headphone version of music, so I can enjoy myself.

 

[ruinedx]

Ah, but the HD820 is not truly a closed headphone more like partially closed, partially open. Also the first closed headphone I'm aware of to use the curved glass and dampening combo to avoid reflecting too much directional sound back into the headphone, whilst including porting to reap the benefits of omnidirectional bass response of a closed back. The HD820 with it's unique design provides more audible improvements over HD800 than it does isolation or leakage prevention....and it fixes the main audio problems the hd800/hd800S have stock while retaining their realistic sound signature. It's not perfect but it's the best I've heard out of the box with no mods or EQ

But in reference to the HD600, the open back HD700 would be my preferred pick in a similar price range.

 

[Midgetguy]

Ah, but the HD820 is not truly a closed headphone more like partially closed, partially open. Also the first closed headphone I'm aware of to use the curved glass and dampening combo to avoid reflecting too much directional sound back into the headphone, whilst including porting to reap the benefits of omnidirectional bass response of a closed back. The HD820 with it's unique design provides more audible improvements over HD800 than it does isolation or leakage prevention....and it fixes the main audio problems the hd800/hd800S have stock while retaining their realistic sound signature. It's not perfect but it's the best I've heard out of the box with no mods or EQ

But in reference to the HD600, the open back HD700 would be my preferred pick in a similar price range.

I'm not sure which headphone I would've picked because both sound pretty good to me. Different sound signature, but I find both enjoyable. The HD600 easily won my pick before as at the time, the HD700 cost way more than the HD600 and I just found that wholly unjustified.

 

[Deolum]

My HD600 new Version just arrived.

First impression: sounds good but maybe not that endgame that i expected after reading this thread. Especially good with classical music but bad with electronic and pop music. Very little bass and tends to be a bit harsh. Natural sound in comparison to other headphones. A Stax Lambda Pro is easily better but the HD 600 sounds more natural which i like. Overall very easy to drive. Didn't need that much power as i expected. Around 3 times more than a Grado.

Do the bass and the heights get better with burn in? It's a b stock version so it's already run a bit.
Also the clamping force is very tight at the moment.

 

[gimmeheadroom]

My HD600 new Version just arrived.

First impression: sounds good but maybe not that endgame that i expected after reading this thread. Especially good with classical music but bad with electronic and pop music. Very little bass and tends to be a bit harsh. Natural sound in comparison to other headphones. A Stax Lambda Pro is easily better but the HD 600 sounds more natural which i like. Overall very easy to drive. Didn't need that much power as i expected. Around 3 times more than a Grado.

Do the bass and the heights get better with burn in? It's a b stock version so it's already run a bit.
Also the clamping force is very tight at the moment.

Brain will burn in if you're used to listening to a headphone with unnaturally emphasized bass. Same thing about treble. The 600s are just really smooth. It's all there in the right proportions. Keep listening

Clamp, yeah. It's jaws-of-death on your skull. You have to be tougher than the headphone. It does get better but it takes longer than I would like.

If you don't have enough amp they will sound lifeless, not have enough bass etc. What amp are you using?

 

[Deolum]

Brain will burn in if you're used to listening to a headphone with unnaturally emphasized bass. Same thing about treble. The 600s are just really smooth. It's all there in the right proportions. Keep listening

Clamp, yeah. It's jaws-of-death on your skull. You have to be tougher than the headphone. It does get better but it takes longer than I would like.

If you don't have enough amp they will sound lifeless, not have enough bass etc. What amp are you using?

At least they fit good and don't fall off if i shake my head.

My amp has more than enough power and can drive a Susvara or HE-6 with no problem. An Audiovalve Solaris. I run them on the lowest gain on 2,5/10 on the poti. Grados run at 1/10.

Other headphones i'm used to are Grado GS1000e or Akg 702 so not particulary bass boosted. But even in comparison to those the HD600 feels basslite. Overall tuning is very nice though. Maybe burning in gives the little missing bass and makes the treble a bit more pleasant.

 

[ruinedx]

My HD600 new Version just arrived.

First impression: sounds good but maybe not that endgame that i expected after reading this thread. Especially good with classical music but bad with electronic and pop music. Very little bass and tends to be a bit harsh. Natural sound in comparison to other headphones. A Stax Lambda Pro is easily better but the HD 600 sounds more natural which i like. Overall very easy to drive. Didn't need that much power as i expected. Around 3 times more than a Grado.

Do the bass and the heights get better with burn in? It's a b stock version so it's already run a bit.
Also the clamping force is very tight at the moment.

For electronic music the HD700 murders the HD600 IMO. That is one of the primary genres I listen to and the HD600 basically failed in that genre. It seems though since they went out of production the price on the HD700 has gone way up, though. HD700 sounds very good with electronic (better than HD800 even), with HD700 only being topped by the HD820 from what I've owned and heard.

 

[evonimos]

Hello,

Impressions being a subjective matter, i'll add my own.

It is been a year since i got a pair of HD600. I though it will be a nice addition since i already owned and enjoyed a pair of HD518, a pair of HD559 (foam removed) and an HD599. My decision was based on the fact that since I enjoyed my HD599 so much, i might as well try the HD600 which everyone agrees it is a classic.

However, my HD600 is rarely being used and spends 99% of its time in its nice box. I had high hopes for it being an upgrade over my beloved HD599, but to my ears it just couldn't win the battle.

My choice still remains the HD599. It wins in terms of soundstage width and depth, comfort, and overall sound signature, especially bass. I tried it with a dedicated DIY OTL tube amp to give it some substance and soundstage which did improve things to a degree, but so it did on my HD599.

Still, it remains a classic and probably rightly so.

 

[ruinedx]

Hello,

Impressions being a subjective matter, i'll add my own.

It is been a year since i got a pair of HD600. I though it will be a nice addition since i already owned and enjoyed a pair of HD518, a pair of HD559 (foam removed) and an HD599. My decision was based on the fact that since I enjoyed my HD599 so much, i might as well try the HD600 which everyone agrees it is a classic.

However, my HD600 is rarely being used and spends 99% of its time in its nice box. I had high hopes for it being an upgrade over my beloved HD599, but to my ears it just couldn't win the battle.

My choice still remains the HD599. It wins in terms of soundstage width and depth, comfort, and overall sound signature, especially bass. I tried it with a dedicated DIY OTL tube amp to give it some substance and soundstage which did improve things to a degree, but so it did on my HD599.

Still, it remains a classic and probably rightly so.

I have to speculate that while the HD600 is a great headphone and I am sure many love it, I think its a real possibility that it's been elevated beyond what it deserves because some audiophiles believe "neutral" sound is "correct" sound while that is not necessarily the case when listening to music with headphones.

Therefore when one learns the HD600 is a very "neutral" headphone confirmation bias then creeps in and it is recommended as audiophiles don't want to be perceived as "incorrect" or recommending something "colored" as that is perceived as negative in some purist circles.

My experience was much like yours, I found the hd600 underwhelming and uninspired. It may be very neutral, but unless you audibly have extensive experience with that in a headphone and have definitely heard all the more modern alternatives I would not assume neutral means better sounding or more correct sounding.

Some of the reviews ive read lately it seems more like the reviewer is making stereotypical assumptions of sound based on the frequency curve and reviewing the frequency curve moreso than the headphone even though frequency curve measurements fail to capture all of the aspects of sound of a headphone and how we psychoacoustically interpret those aspects.

 

[evonimos]

Impressions on anything and especially on what sounds 'right' can be a very subjective business.

That's no problem for most people, since they know that we buy headphones to enjoy them on a personal level.
The way we ourselves perceive what sounds right, based on our own preferences, our own music and our own accompanying gear.
If we enjoy them that's all that matters, regardless what this or that reviewer claims or what graphs and measurements imply.
That is not to say that there's absolutely no common ground on certain aspects of audio, it's just that preferences do vary.

Now, the HD600 is certainly a classic headphone, one that was ground-breaking when released and remains a good one today.
However, for me the HD599 is the better choice and a move by Sennheiser to the right direction regarding sound signature and especially sound-stage.

A move Sennheiser will hopefully keep on following in the future with their upcoming models.
I'd be the first to invest in any headphone that improves on the philosophy of the HD599.
Say, an improved HD599 with more control and impact in the lower band, more precise imaging, even wider sound-stage and maybe a bit more refinement in mids/highs.
That would make it an instant-buy for me even if priced 3 times its current cost.