ZMF Caldera Headphone Review

[amirm]

But I am sure that you will choose the low hanging fruit-approach of zero scientific curioucity claiming someone is spreading "FUD" again and the holy bible of Harman forbids us to think in that direction.

What are you talking about??? I have spent $14,000 on a headphone test fixture and spent hundreds of hours testing headphones. In every instance, I put the research to test by listening to the headphone, developing an EQ and assessing audibility of frequency response variations relative to the target.. What have you done? Nothing. What has Zack done? Nothing. You have just drank your own Kool-Aid thinking that entitles you to a defensible position. It doesn't. I give negative reviews to 60% of products I test. Countless new people join to complain and defend what they have bought. As you, they bring nothing to the discussion. Just arguments and claims that this and that reviewer likes their gear so we must be wrong. We humor you but at some point you need to stop with the pleadings. We know you are unhappy that my assessments, backed by years of research say you are wrong about the fidelity of this headphone. Move on. You can't defend against this with arguing with words.

 

[amirm]

Its the dogmatism, arrogance and complete lack of scientific curiocity that are really remarkable.

Nonsense. We have repeatedly said the predictive power of the research is between 60 and 70%. Your ignorance of the research and how incredible it is to have this level of confidence doesn't make us wrong and certainly not dogmatic. We know that the alternative -- that anything goes -- is illogical at best. I recently recommended a $20 IEM that conforms to this research. This is but one positive impression of this IEM:

Darn you, @amirm! I had you guys delete my account just a bit ago thinking I was cured of my ceaseless audiophile forum reads once and for all. Well, I relapsed this week. (I'm okay to anyone reading. This wasn't a psychological issue. I just wanted to devote more time to other pursuits.) Further, I saw this review, I tried them and, by golly, I cannot get my ears off of them. They are so good I was compelled to come back to express just how good they are! I did not do double blind testing, but I own both these and Elysian Annihilators (which, by the way, are going to be sold promptly, and if that isn't a seal of approval for these IEMs, I honestly don't know what is). Every person in my household who tried both overwhelmingly preferred the 7Hz Salnotes Zero. Perfection. These are giant killers and not proverbially and figuratively either. If they were priced $100, they would still be totally worth it. Thank you for saving my wallet, Amir, (for now, that is... the Annihilator proceeds are going towards some Topping goodness and Ascend LXs!) and happy to be back on the forums from my semi-hiatus!

We follow the science which gives us great help in proper assessment of headphones. The only think "arrogant" would be to ignore it all and think you are smarter than the rest of us and the researchers. You haven't even bothered to do one controlled test. Nor has your designer. And you dare to put those labels on us? It is this illogical thinking that drives many people away from your subjectivist world into reasoned work that we do here. We are not growing by accident. We are doing the right thing.

 

[amirm]

Regarding previous posts, yeah its very nice of you to address things said as a "high school level", instead of actually addressing the points made, like research data I asked for after assumptions you made and things like very limited size of Harman research from standpoint of socilogy research standards and issues with the richness and of presented data and independend evaluation of it.

Back to FUD again. Oh, our research lacks "richness." What does your stance have? Nothing. You don't even have that research. You are running with opinions of random people online without a single bias controlled test. And you dare complaining about what we rely on?

 

[isostasy]

As a presumably scientific thinking guy you could try to find out how the designer managed to create a headphone that many reviewers, listeners and buyers describe as the most dynamic driver-like sounding planar allrounder, with natural sound signature.

You must be able to realize that this wouldn't be a scientifically robust study in any field? It would be like writing a paper titled "why is Cornflakes such a healthy cereal?" before actually confirming whether it has any positive or negative effects on health! Not only that, before even laying out criteria for what effects are considered positive or negative.

Then make one.

What on earth do you mean? Amir says there is no research that backs the response so you say he needs to make the research? This isn't how research works you don't make something then conduct "research" to back up what you've made!!

 

[Benesyed]

Is there a thread specifically dedicated to discussing the Harman papers and research in general? Would that be the measurements thread? @amirm ?

Thank you everyone for a very intersting discussion

 

[Benesyed]

I think that this study's methodology makes a bit immaterial to know which pair of headphones was which. It was discussed in this thread (that post and subsequent posts) : https://audiosciencereview.com/foru...ng-society-2023-conference.48497/post-1741065

The issues are :
- they made a very poor choice for the reproduction headphones : Beyer DT 770 Pro. This pair of headphones will have more coupling issues and inter-individual variation than a pair of headphones like the HD800, for example. Besides, if it is like the DT 700/900 Pro X, the dip at around 4kHz might be of the kind that's resistant to EQ and makes comparisons in that band a bit pointless.
- they used a 30 band GEQ to EQ the reproduction headphones to the different FR curves under test (whether the approximated targets, the headphones, or the modifications to these curves). This prevented the reproduction of sharp peaks and dips, and as some headphones' individual features have been shifted on the X axis, the GEQ could have had a role to play in that regard.
- even still, it seems that the approximated targets, which were created by Mad_Economist in that thread, were not perfectly captured. They're also shifted on the X axis a little bit, and I am not certain that the use of a GEQ alone could have caused this. Don't hesitate to ask him about this, he's probably looked into it more than I did. The "v2" versions of the two approximated targets are a modification of them, with additional energy around 3-9kHz.

So it's really difficult to know exactly what the listeners actually experienced and compared, and in my view it is inappropriate to interpret that article with excessive exactitude. In my opinion it's best to keep it at a very general picture of the kind "people want their headphones' response to be sensibly shaped", "sensibly" meaning "very roughly in the spirit of the general shape of Harman's target", ie avoid zany responses, and by "very roughly" I mean don't get caught up in any nitpicking within a 3-5dB window at the very least (and don't necessarily think that APHarm2018v2 is the right target to use for the 5128).



The detailed preference data is freely available here : https://zenodo.org/records/8388242
ThomasXia provided some useful graphs to analyse it in the thread linked above.
Also provided as well are the simulated FR curves using the 30 band GEQ (so not exactly the FR curves of the actual headphones).

Am I interpreting this correctly to mean that every headphone curve had at least one person ranking it as 100% most preferred?

 

[DenverW]

I don't disagree with you, and I do believe in the scientific method and verifiability, which is why I suggested the Harman research should be verified before being put into practice or measured against as an industry standard.

Here's an analogy that maybe illustrates better my feeling - say Ford over the past five years did a significant amount of research on buyer preference of car color. What they found was 64% of car buyers preferred their car to be black. Then a popular car reviewing publication began dolling out bad reviews if the car was in any color but black given the new research. Furthermore, they began advocating for the entire industry to only release cars in black, because a majority of people prefer it. Companies could also release cars in other slightly different shades of black, but ultimately, a variation of black is the only real option for a positive review. Given all of the bad reviews, car companies actually started doing it, given it was hurting their bottom line.

Now a high-end boutique car company comes along and releases a car in purple. Its niche audience really loves the new color, even though it isn't verified by any research. Regardless, the car publication gives it a bad review, predictably, but says if you spray paint it black, then it gets a full recommendation! They also go onto say, if you follow our testing methods, you will find that your preference actually IS black, you just aren't aware of it.

Do you see why that might be irritating to the niche audience of the purple car company?

Continuing on with my car analogy (I'm not even into cars, but a lot of people seem to be), using tubes in your audio gear is like driving a classic sports car. It isn't the best performing, it doesn't even have power steering, it gets horrible MPGs and overall is terrible inefficient. But it looks cool as hell and is still extremely fun to drive, compared to a sports car with contemporary engineering and technology.

Thank you! I couldn't appreciate this more, as it does give me a lot to think about and has been on my mind. I know some people are having trouble with the analogy, but I found it very apt. If the car reviewing publication was posting reviews saying only how the car varied from black, and that 64% of the population may not appreciate that, but YOU might, it would be one thing. But what if the publication posted reviews either directly or by implication that variation was bad? What if SOME variation was all right, if it subjectively looked good, but then other variation wasn't? Where is the line?

And the publication became so popular that the readers took it upon themselves to enforce the standard? Even if quite a few of them, if not the majority of them didn't even know if they preferred the standard black, because they'd never seen or experienced different colors?

This is what I've been struggling with, thank you.

 

[DenverW]

Headphones have identical characteristics to cars in that manner: their look/color. The Caldera got rave reviews from me in that respect. More so, I have said that it has influenced many people to buy it, the actual performance notwithstanding. So your analog makes no sense.

It's analogy. You're probably a victim of auto correct, it zinged me earlier with "Harmon", lol! Although I do like the actor!

Sorry to double post! I try to get everything into one.

 

[amirm]

And the publication became so popular that the readers took it upon themselves to enforce the standard?

We don't "enforce" anything. We measure and follow industry standards and research on what is likely a good sounding headphone.

That aside, what if you are one of the people who belongs in the 65% that prefer it this way? You like the 20% to force the market to fragment and thereby far reducing your choices of products? Today when someone asks me which headphone to buy that follows the Harman research for $500, I have no answer for them. Even at $1,000 I have no answer. We just got a $2,000 answer (Dan Clark E3).

BTW, we have made a difference in IEMs where there seems to now be small flood of IEMs that follow Harman research. The results has been overwhelmingly positive. While they all more or less follow the target, there is still enough differentiation between them to suite different people. This is what we want. A "line" that is more or less a line. Not wild west where anything goes.

Finally, no one is foreclosing any options on you. Even if the entire world went to Harman target, you can use EQ to adjust to taste. Majority would get to listen without it but others can still choose to adjust.

 

[Tachyon88]

Finally, no one is foreclosing any options on you. Even if the entire world went to Harman target, you can use EQ to adjust to taste. Majority would get to listen without it but others can still choose to adjust.

I think this is part of the friction. This segment doesn't want to use EQ and want to buy endless amounts of electronics, cables, gear "matching" and "unique" frequency responses that happen to be headphones,. They could actually figure out what they really like by having an objective standard in which to tailor their taste, but that requires doing EQ. Many think that if you have to EQ, then the HP is "broken". Also many think that if everything is Harman then everything will sound the same and be "boring", yet even that isn't true. I tune all my HP to Harman and they all have their unique characteristic. The fun is still there.

 

[DenverW]

We don't "enforce" anything. We measure and follow industry standards and research on what is likely a good sounding headphone.

That aside, what if you are one of the people who belongs in the 65% that prefer it this way? You like the 20% to force the market to fragment and thereby far reducing your choices of products? Today when someone asks me which headphone to buy that follows the Harman research for $500, I have no answer for them. Even at $1,000 I have no answer. We just got a $2,000 answer (Dan Clark E3).

BTW, we have made a difference in IEMs where there seems to now be small flood of IEMs that follow Harman research. The results has been overwhelmingly positive. While they all more or less follow the target, there is still enough differentiation between them to suite different people. This is what we want. A "line" that is more or less a line. Not wild west where anything goes.

Finally, no one is foreclosing any options on you. Even if the entire world went to Harman target, you can use EQ to adjust to taste. Majority would get to listen without it but others can still choose to adjust.

You don't feel that it's enforced here? I'm getting a completely different perspective, then. I assume there are outliers, of course, but they seem to be supported rather than reigned in. There are quite a few aggressive comments in the thread based more toward individuals rather than the data, and I only saw one post asking someone to keep it toned down.

I was told that no one cared, and it was "bs" based on my first inquiry.

 

[NTK]

My reading of Dr. Olive's Acoustics Today article is that 64% of the listeners prefer the Harman target as is, whilst 15% prefer the Harman target with more bass and 21% prefer the Harman target with less bass.

Can someone point out to me which publication says the Harman target is preferred by 64%, meaning 36% do not prefer it?

 

[amirm]

You don't feel that it's enforced here?

Not at all. You have seen @solderdude who is one of our most valued members repeatedly say he likes a different target curve. You see us sanctioning him?

To be clear, you can say you like a headphone with no bass, treble or midrange and you would be fully within your rights in this forum. Now, tell that to the rest of us in the form of argument of your position being superior to ours and we will argue back. And you may get sanctions if it came across that you were only here to tease the membership and create friction. That has nothing to do with the specific topic here and is a general rule of the forum.

 

[DenverW]

Not at all. You have seen @solderdude who is one of our most valued members repeatedly say he likes a different target curve. You see us sanctioning him?

To be clear, you can say you like a headphone with no bass, treble or midrange and you would be fully within your rights in this forum. Now, tell that to the rest of us in the form of argument of your position being superior to ours and we will argue back. And you may get sanctions if it came across that you were only here to tease the membership and create friction. That has nothing to do with the specific topic here and is a general rule of the forum.

I generally try to express my preferences as exactly that: my preferences. Having been a passive observer of these forums for quite a few years I've developed the impression that expressing a non conforming opinion as 'superior' is very bad, but expressing a conforming opinion as 'superior' is acceptable. I'm sure this has been expressed many times in different and probably negative ways, so hopefully my comment does not come across as hostile or to create friction.

 

[raif71]

I think this is part of the friction. This segment doesn't want to use EQ and want to buy endless amounts of electronics, cables, gear "matching" and "unique" frequency responses that happen to be headphones,. They could actually figure out what they really like by having an objective standard in which to tailor their taste, but that requires doing EQ. Many think that if you have to EQ, then the HP is "broken". Also many think that if everything is Harman then everything will sound the same and be "boring", yet even that isn't true. I tune all my HP to Harman and they all have their unique characteristic. The fun is still there.

"doesn't want" may not be accurate. In my case, I'm not using computer as source of music files so no PEQ. I'm using DAPs but then again if the players have rudimentary EQ, I'd rather not use them coz too cumbersome and not as accurate as PEQ.

 

[majingotan]

"doesn't want" may not be accurate. In my case, I'm not using computer as source of music files so no PEQ. I'm using DAPs but then again if the players have rudimentary EQ, I'd rather not use them coz too cumbersome and not as accurate as PEQ.

Nice to see a Fellow DAP user as source here as well . It feeds my Schiit Yggdrasil+ More is Better DAC via USB. No EQ, no DSP, purist digital approach thus I need to have my headphone comform to Harman mids and treble FR response (Susvara in this case) since they sound the most natural to my ears and to 64% of listeners. Caldera sounded wonky to me as proven by Amir's measurements.

 

[Madlop26]

I don't disagree with you, and I do believe in the scientific method and verifiability, which is why I suggested the Harman research should be verified before being put into practice or measured against as an industry standard.

Here's an analogy that maybe illustrates better my feeling - say Ford over the past five years did a significant amount of research on buyer preference of car color. What they found was 64% of car buyers preferred their car to be black. Then a popular car reviewing publication began dolling out bad reviews if the car was in any color but black given the new research. Furthermore, they began advocating for the entire industry to only release cars in black, because a majority of people prefer it. Companies could also release cars in other slightly different shades of black, but ultimately, a variation of black is the only real option for a positive review. Given all of the bad reviews, car companies actually started doing it, given it was hurting their bottom line.

Now a high-end boutique car company comes along and releases a car in purple. Its niche audience really loves the new color, even though it isn't verified by any research. Regardless, the car publication gives it a bad review, predictably, but says if you spray paint it black, then it gets a full recommendation! They also go onto say, if you follow our testing methods, you will find that your preference actually IS black, you just aren't aware of it.

Do you see why that might be irritating to the niche audience of the purple car company?

Continuing on with my car analogy (I'm not even into cars, but a lot of people seem to be), using tubes in your audio gear is like driving a classic sports car. It isn't the best performing, it doesn't even have power steering, it gets horrible MPGs and overall is terrible inefficient. But it looks cool as hell and is still extremely fun to drive, compared to a sports car with contemporary engineering and technology.

Extremely poor analogy, only valid if Amir would be recommending headphones according to color or looks. No, is about technical performance. A reviewer recommending a car by color does not make sense (at least for the people interested in technical performance); certainly most people here, will be more interested in the car technical performance than its color and assessing technical performance is what Amir does here.

 

[Chester]

Nothing is stopping anyone from taking the data Amir produces (golfing panther or headless panther) and deciding if it looks like something that will appeal to them.

The amount of energy that goes into defending one’s purchases, across all forums is really something. We could power an entire village if we could harness it!

Yes, there are some people here who are a bit blunt and dogmatic but that could be said about all forums. You can hardly blame the founder for those people. Generally though, I see more challenging of the founder here than in most forums. And he generally takes it well, especially given the way it is delivered at times.

If you can’t see the huge value being offered here then I feel sorry for you and hope you do some day.

Why don’t we all just relax up, just a little bit. They’re only headphones.

 

[isostasy]

Thank you! I couldn't appreciate this more, as it does give me a lot to think about and has been on my mind. I know some people are having trouble with the analogy, but I found it very apt. If the car reviewing publication was posting reviews saying only how the car varied from black, and that 64% of the population may not appreciate that, but YOU might, it would be one thing. But what if the publication posted reviews either directly or by implication that variation was bad? What if SOME variation was all right, if it subjectively looked good, but then other variation wasn't? Where is the line?

And the publication became so popular that the readers took it upon themselves to enforce the standard? Even if quite a few of them, if not the majority of them didn't even know if they preferred the standard black, because they'd never seen or experienced different colors?

This is what I've been struggling with, thank you.

No, you are having trouble with this analogy because it doesn't work and it isn't apt.

Car color is entirely subjective. The color car you choose is just an expression of your aesthetic preference and you know it has nothing to do with anything else.

But headphones are for reproduction. This is what baffles me about these discussions: people start talking about them like they're creative instruments or some expression of preference as subjective as color. Stop thinking about headphones as expensive toys, furniture, bling, or whatever is in your head and reduce it first to just a device for reproducing a signal. I'm not saying you're not allowed to want it to look good but first and foremost it's a device for reproducing a signal.

So, lets take your car color analogy. I bet car manufacturers do do research on preferred color and paint their cars accordingly, because bright pink probably isn't as popular as just plain black or navy. So they would be stupid to produce the same number of cars in bright pink as black or navy. All the most preferred colors would sell out first and all you'd be left with is the least preferred colors. Do you see? So in a car magazine they might mark it down by saying "they sent us a black one but you can't actually get it in this color any more, the only colors left are bright pink, mint green, and fire orange so we can't recommend it to most people unless you love it so much you can afford to repaint".

Additionally, though color is a frequency spectrum, preference for color doesn't necessarily follow any rules regarding affinity of shades and tones the way @L0rdGwyn tried to claim. So sure, grey is closer to black than red in that both grey and black are both entirely desaturated, but that has no bearing on my preference. If I said I like red and black but not grey you can't say "but grey is closer to black than red'. It doesn't work like that.

Do you see now that your apparently "apt" analogy doesn't work at all?

 

[isostasy]

You don't feel that it's enforced here? I'm getting a completely different perspective, then. I assume there are outliers, of course, but they seem to be supported rather than reigned in. There are quite a few aggressive comments in the thread based more toward individuals rather than the data, and I only saw one post asking someone to keep it toned down.

I was told that no one cared, and it was "bs" based on my first inquiry.

I generally try to express my preferences as exactly that: my preferences. Having been a passive observer of these forums for quite a few years I've developed the impression that expressing a non conforming opinion as 'superior' is very bad, but expressing a conforming opinion as 'superior' is acceptable. I'm sure this has been expressed many times in different and probably negative ways, so hopefully my comment does not come across as hostile or to create friction.

No. Expressing any opinion as 'superior' is not taken well. You will see just as much that when members insist that only an exact match, 20Hz-20kHz, of the Harman target (OE 2018 or IE 2019 depending on product) is good enough that they aren't taken seriously.

I will admit that when Amir reviews a product which is a Veblen good it gets more flak and snide comments. If you're fortunate enough to be able to buy Veblen goods I think you should suck it up. You'll note Dan Clark's headphones get similar comments even when they do perform well.