ZMF Caldera Headphone Review

[solrage]

I have a whole playlist of such tracks one of which gets used in every speaker and headphone review. This is one of the powerful strength headphones have even over best speakers in that they have no trouble traversing down to 20 Hz and even lower. It is delightful to hear music like this and give you an idea of what is really in you music.

I have no doubt you can select for and create a playlist of tracks with ~20Hz content if you go looking for it, but the vast majority of music simply doesn't have content down there. Most all rock, metal, classical, folk, or jazz, is not going to have 20Hz frequencies because almost no instruments play that low, and the ones that do are rarely used. Back when I bought my 21" subwoofer for my speaker system I actually got into finding organ music that has 20Hz (and even lower!) content, but organ music is an incredibly niche interest. I agree it's nice to hear music that has that content, but I can also tell you first-hand that even Harman-tuned headphones with good low-bass can't touch what a subwoofer can do with those frequencies.

They both lack it. What HD650 has which Caldera doesn't is incredibly good lower to mid treble. It puts a smile on my face every time I use it to test a headphone amp. The Caldera is the opposite with a dull sound as I reported in the review. Add some bass EQ to HD650 and it becomes a huge contender for one of the best headphones there is.

And what you say is fair re the mids and treble, but your review for the Caldera put most of the emphasis on the "no bass" as if that was the primary problem when you didn't even mention it on headphones that measure much worse or the same in that area. Also, EQing the HD650 bass doesn't fix the high distortion and just makes it worse.

I don't know how you, the designer and everyone doing sighted subjective testing of a headphone is not biased by its looks, reputation, supposed design and fidelity, other reviewers they have read, and a million other reasons. So don't ask me for bias control when you have no belief in it yourself. Those are massive *and improper* sources of bias.

I have never suggested we aren't biased by such things. In fact, I readily admit I'm biased towards ZMF because of how they look. Still, if they performed terribly I wouldn't use them as much as I do. I'd just be using my HD650s or Aeon all the time and keeping my ZMFs on their racks to look at (it's actually far easier to enjoy their looks that way!). A lack of bias control is only an issue for the side trying to claim some kind of scientific objectivity. Maybe you'd object you aren't doing that, but many around here seem to think that's the case.

If you had watched my video I post video yesterday, you would have seen me explaining why doing subjective reviews without measurements is so wrong. An AI text generator can be substituted for many such subjective reviews and you wouldn't know the difference! After all, how would you be able to denounce them? You have nothing else to dispute their assessment of "this is what I heard."

I haven't objected to you or anyone doing reviews with measurements. What you say about AI reviews can be said of a lot of things, probably including peer-reviewed papers. I don't know what that's meant to prove other than how good AI is at generating human-like text.

The rest of your post seems to follow from your mistaken assumption that I'm somehow opposed to measurements or science or evidence when the truth couldn't be further away from that.

I will tell you: it is that in that there is nothing else out there that comes close to giving us a compass pointing to true north (of correct audio fidelity). Just like a compass, we don't expect it to tell us 1 degree differences in headings. It is not a GPS as I usually say. So don't say it is and then complain that it can't be that. We need to be able to live with ambiguity just like a survivor does in digging his way out of a jungle with said compass.

My own goals have less to do with audio fidelity and more musical fidelity. We know because of the circle of confusion audio fidelity (even if we could determine it with complete accuracy) doesn't necessarily get you towards musical fidelity. Last night I was listening to the Emersons performing Bartok's String Quartets. Phenomenal musicians, but the audio engineering was very hot in the in the 1k-4k region. Not just my "subjective impression" either as I could see it in the analyzer. Now, you can listen to those performances (and many consider them definitive in that music) on a Harman-tuned headphone and be happy about your audio fidelity, while I'll be over here with a headphone like the Caldera (which I wasn't using last night) and be happier that my ears aren't being pierced to death. Sadly, recordings like that are not as rare as I'd wish them. If they were maybe I'd be more enthusiastic about Harman, but I don't think it's a coincidence that a lot of Harman-tuned headphones get criticized by "subjective" users as being bright. I don't think Harman is bright, I just think a lot of recordings are, and those recordings tend to sound very bad on Harman-tuned headphones.

 

[solrage]

The HD600 came out as one of the top ones when a panel tested >30 headphones in 2002 (Swedish Audio Technical Society). The headphones were subsequently measured and HD600 was confirmed to measure well except that it was weak below 100 Hz. I don't really know when ASR started actually, but so far I have not seen anything that contradicts what we found in 2002 (subjective grading SQ in headphones and correlation to measurements) and what Amir have found testing many more headphones. Other than I've found that less bass is preferred when listening to binaural recordings, but that is not what is on topic here.

The HD600/650 have been beloved and something of a standard since I've been into headphones/audio (over 20 years now), but its weak bass has always been the one consistent criticism. My point was that it makes no sense to criticize a headphone like Caldera for having "almost no sub-bass" when we have headphones like the HD600/650 that are demonstrably worse yet don't receive the same criticism.

 

[solrage]

Not to mention costs ten times less.

Cost has nothing to do with performance, though, and if anything this just sounds like you're introducing another bias into the equation where we excuse "bad" performance on cheap headphones but excoriate "better-but-not-ideal" performance on expensive ones, even when the expensive ones are clearly charging more for the design/looks part.

 

[Thomas_A]

The HD600/650 have been beloved and something of a standard since I've been into headphones/audio (over 20 years now), but its weak bass has always been the one consistent criticism. My point was that it makes no sense to criticize a headphone like Caldera for having "almost no sub-bass" when we have headphones like the HD600/650 that are demonstrably worse yet don't receive the same criticism.

My main issue is the 1-5 kHz range, which the HD600 nails, including the range from 100 Hz.

 

[solrage]

My main issue is the 1-5 kHz range, which the HD600 nails, including the range from 100 Hz.

And that's fair, but then that should also be reflected more in the review to maintain some consistency. I think I've said my piece on the 1k-5k issue.

 

[Chagall]

So my theory is that headphones matching that target must be difficult because not one open back headphone matches the target - and those that might be close are not truly worth investing in and building a setup around - basically you name it on all the TOTL headphones from headphone history. It's a simple point. Of course you can EQ a headphone, thanks for reminding me. It's maybe a dumb point but important in a thread demanding headphones to match that target.

My theory is that with the popularisation of headphone measurements and targets, it will become easy all of a sudden.

And I'm talking popular as in mainstream - "what hifi" mainstream.

 

[fredristair]

You might be right. The concern is that actually it will degrade many aspects of sound quality that are not entirely captured yet with measurements to pursue that frequency response. But fair enough.

 

[IAtaman]

My main issue is the 1-5 kHz range, which the HD600 nails, including the range from 100 Hz.

HD600/650 indeed has a much "fuller" ear gain area compared to Caldera. Given their error curve is more or less flat, I image Caldera's error curve will be already tilted towards bass due to dips in highs. For that reason, I think giving Caldera a bass boost without filling the holes in treble might actually take it further away from neutral tonal balance, not closer to it.

The idea that every dip we fill, every peak we flatten brings the headphone's tonal balance towards neutral, without paying attention to overall tilt is a misunderstanding of the research in my opinion.

 

[MacClintock]

The HD600/650 have been beloved and something of a standard since I've been into headphones/audio (over 20 years now), but its weak bass has always been the one consistent criticism. My point was that it makes no sense to criticize a headphone like Caldera for having "almost no sub-bass" when we have headphones like the HD600/650 that are demonstrably worse yet don't receive the same criticism.

Firstly, the HD600 was indroduced long before the Harman research. Secondly, the HD is beloved because it follows quite closely the target above, say, 500Hz. Something the Caldera doesn't, although the research is out there, so it is either intentional or ignorant of the creator not to do it. Take the HD600, EQ it for more bass and you have a much better headphone than the Caldera without EQ.

 

[amirm]

I have no doubt you can select for and create a playlist of tracks with ~20Hz content if you go looking for it, but the vast majority of music simply doesn't have content down there.

What, you are going to tell me to adapt my listening to what the equipment does??? No, I did not go looking for anything. I let Roon play music for me for hours in the day and when I hear something with impressive bass that I like, I add it to my playlist. I happen to have an RME ADI-2 Pro which shows me the spectrum of music so I am pretty informed about what has it, and what doesn't. I trust you don't have such a thing so don't even know what is in your music as you listen.

 

[amirm]

but I can also tell you first-hand that even Harman-tuned headphones with good low-bass can't touch what a subwoofer can do with those frequencies.

Depends on what you mean by "touch." Room modes radically change what happens in bass response. You can EQ it but can't get it to be as clean as it is with headphones. They don't bring tactile feedback but the purity of bass in headphones can be incredible.

 

[amirm]

And what you say is fair re the mids and treble, but your review for the Caldera put most of the emphasis on the "no bass" as if that was the primary problem when you didn't even mention it on headphones that measure much worse or the same in that area.

Did you not read the review? Here is the first measurement:

It absolutely mentions both bass short fall and poor response in treble. The bass deficiency is flat so impacts every bass note so it is easy to identify it in music. The troughs in treble require the right notes to hit there so statistically can be less audible. But both corrections were needed for proper fidelity as I mentioned in my listening tests:

"There was almost no deep/sub-bass response so that was the first low hanging fruit to fix with equalization:....That alone made a remarkable difference. But the job needed to be completed with the three other filters to fill those holes. Once there, I liked the effect very much but thought the sound was a big bright so took down the peaks a bit. With the complete package, the transformation was dramatic as you can imagine. There was impressive bass and excellent detail and quite good spatial effects."

FYI the owner deployed the treble EQ but dialed it down 25% which is fine by me.

 

[amirm]

Respectfully EQ all you like (not for me). But I disagree that the lack of headphones out of the box to match that preference is because the designers 'didn't want to'. Just seems like a real technical limitation there where you are robbing Peter to pay Paul and there is no great headphone that has what you are asking (yet).

With all due respect back, we don't care what your opinion is, only what you can demonstrate with facts and not hypothesis and lay theories. You are an anonymous poster with no stated or demonstrated qualification in the field, on technical or business side to make these claims.

Even your opinion about yourself is suspect. My late grand-father-in-law, may he rest in peace, hated cheese. We had him over and my wife made chocolate cheese cake. He ate and loved it. To that end, I am pretty sure if you were put in a controlled test, we could get you to like an EQed headphone more than not. This is proven in research where a lot of work is done by equalizing a surrogate headphone to response of others.

 

[amirm]

So my theory is that headphones matching that target must be difficult because not one open back headphone matches the target

You have no grasp of your facts. I already post that Dan Clark Expanse that is open back with harman tuning:

So if that is what you were assuming, it is time to rethink your assumptions.

 

[Benesyed]

They did. For their top of the like headphone, they chose essentially Harman as their target curve:
View attachment 334712
It scores 99/100 on the Harman preference score.


What makes the HD600 so great is their Harman compliance:
View attachment 334714

That they roll off in the bass is as expected from a near 30 years old design. It's not what makes them great.

I'm thinking about getting the HE1 next year as a lavish gift to myself. Instead of a sport car that I would inevitably crash and die in

 

[IAtaman]

I'm thinking about getting the HE1 next year as a lavish gift to myself. Instead of a sport car that I would inevitably crash and die in

What sports car can you get for $50K?

 

[fredristair]

HE1 might be a good example of unlimited resources towards a headphone - and not matching the 'ideal target' in the bass, but definitely making an attempt to be a little more than flat in the bass, and of course matching the target pretty impressively. It comes back to the idea of whether pursuing all that bass really comes at the expense of other aspects of the technicalities in a headphone. I still think speakers are more suited for all that sub-bass, but I've read otherwise here. it was enjoyable briefly to tune an LCD-X to have all that, but I tended to go back to the stock response generally.

 

[Benesyed]

What sports car can you get for $50K?

Oh no my point was instead of sinking 150+ dollars on a sports car, I am saving a 100k by only getting an HE-1

Its just simple economics

In any case it seems like they are no longer taking orders. Hopefully that's not permanent. Or maybe its better that way ahaha

 

[trollbearpig_what]

Just throwing in my 2 cents as having owned the Caldera for a year and recently demoed and compared the Susvara for a week. They certainly have a thickness to the sound, and the detail, speed and transparency is absolutely there even more so than the Susvara. Where I found them lacking was in the mid range which felt recessed. On tracks where I felt the vocalist should be center stage, it feels like they are far away - and with the mid range carrying so much emotion of many songs, this means many tracks lose their magic. It's hard to explain, as they are so detailed it's not as if you can't hear every detail from the vocalist, but it just doesn't feel like an intimate performance to me or very center stage, the vocals are just another part of the track with a million other details that all get blended. Another thing I love about some headphones are those moments where the sound feels as it's coming from nowhere or anywhere but the headphone, those moments never happened with the Caldera as they do on the Susvara.

All in all I found the Susvara to be far more balanced tonally, provide me with detailed yet intimate performances with great staging and just the right amount of bass to satisfy even myself who listens to very bass heavy music. They just carry more emotion, and due to their ethereal sound signature I found myself able to listen for hours at a time vs Calderas punchiness limiting my listening time.

 

[Godataloss]

You are close. If we were to pick a flavor of ice cream that most people would like, wouldn't chocolate be the one instead of a random one? Pretty sure Dorian Fruit flavored ice cream wouldn't make it.....

What joy is there in a world where store shelves are inundated with objectively-idealized chocolate ice cream?

I agree. To me it's a bit like saying "we did a survey of the country on how to punish murderers and most people advocate capital punishment - therefore all murderers should be executed!"

Or "There are more Christians on Earth than any other religion- therefore all religions should be Christian"

And maybe that is at the root of my problem- Harmon becoming dogma. What originally attracted me to ASR was the lack of subjectivity. In a world where nobody's opinion matters, everyone is equal.