ZMF Caldera Headphone Review

[DenverW]

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?

No, that is what you think headphones are for. You speak in absolutes with your opinion, while telling others their thoughts are wrong. If you view a pair of headphones in that manner that is perfectly acceptable for you, and I would not tell you you're wrong. Please show the same courtesy and respect to my thoughts as well.

You can pick apart an analogy as much as you like, put words in bold or quotes, but it doesn't change that for me, it worked well. In fact, you reinforced my thoughts by your response more than changed them.

 

[DenverW]

But Caldera looks ten times better.

Heh! Honestly, I LOVE the look of the aeon line up and ether C from DCA. If ever I wanted a sighted bias to take effect it would be there, because between looks and comfort I really wanted to like them, but they're so lifeless and dry to my ears (YMMV) .

And speaking of DCA, is there anything I need to know as far as affiliation? They've been brought up in this thread more times than would seem normal in a discussion (and not a comparison) with another headphone.

 

[IXOYE]

Heh! Honestly, I LOVE the look of the aeon line up and ether C from DCA. If ever I wanted a sighted bias to take effect it would be there, because between looks and comfort I really wanted to like them, but they're so lifeless and dry to my ears (YMMV) .

And speaking of DCA, is there anything I need to know as far as affiliation? They've been brought up in this thread more times than would seem normal in a discussion (and not a comparison) with another headphone.

I was joking, I don't care much about looks, to me sound and comfort comes first

 

[MacClintock]

But Caldera looks ten times better.

True, but do you buy a headphone or furniture?

 

[oleg87]

And speaking of DCA, is there anything I need to know as far as affiliation? They've been brought up in this thread more times than would seem normal in a discussion (and not a comparison) with another headphone.

I think it's just that their Stealth and Expanse models (and whatever the new one's called) are known to be exceptionally compliant to the over-ear Harman target.

Though for me, that is illustrative of the limitations of headphone FR measurements, since I really did not get on well with the Expanse, even though the Harman target usually works well for me.

 

[amirm]

And speaking of DCA, is there anything I need to know as far as affiliation? They've been brought up in this thread more times than would seem normal in a discussion (and not a comparison) with another headphone.

I have no affiliation with any company, Dan Clark or otherwise. As noted, they are one of the few companies producing high-performance Harman compliant headphones so I quote them. I wish there were a lot more examples and if so, I would be citing them especially if they were at lower cost.

 

[Soria Moria]

I wish there were a lot more examples and if so, I would be citing them especially if they were at lower cost.

Sennheiser in the future maybe?

 

[DenverW]

I have no affiliation with any company, Dan Clark or otherwise. As noted, they are one of the few companies producing high-performance Harman compliant headphones so I quote them. I wish there were a lot more examples and if so, I would be citing them especially if they were at lower cost.

Gotcha, I didn't know if you were friends or some such and wanted to ask.

 

[DenverW]

I was joking, I don't care much about looks, to me sound and comfort comes first

Sound and comfort for myself as well, but I'll admit I place sound high above comfort.

 

[IAtaman]

I think it's just that their Stealth and Expanse models (and whatever the new one's called) are known to be exceptionally compliant to the over-ear Harman target.

Are they really exceptionally compliant to the AE target?

I was curious, because I do have the same perception - but is that true?

As far as I am aware, there is a way to quantify an AE headphone's compliance to the findings of the research : calculating its preference score. I am not claiming it is perfect, but it is what the research suggests. Amir does not do that calculation, but Oratory1990 does. So based on his calculations, here are the scores for current line-up of DCA headphones and their preference scores. (if there are any errors in selection of which headphones are the current line-up, or any clerical errors, those are all mine)

Expanse and Stealth are probably in the Excellent category according to the research but the rest are just Good. And if we were to calculate an average based on this list, it would simply be just Good.

For sake of comparison only, here is a look at some of Hifiman's most popular headphones, again from Oratory's data.

All of them are Excellent as per research. Admittedly, this is not the full line up, and not all Hifiman headphones would score high probably. There might be a selection bias here as well, in the form of what I know of Hifiman are the ones that have high preference score probably. Nonetheless, looking at this table one can also make a strong argument that if a manufacturer was to be called "most compliant to headphone science", that might as well be Hifiman.

Again, for sake of argument, even Meze, which is not known in these circles as "scientifically minded" are not doing too bad. In fact, for their current line up, their average preference score would be higher than that of DCA.

So, you and I, and many other ASR readers probably, if asked would say DCA is the most "scientifically minded" manufacturer, and they do manufacture headphones that are inline with the scientific research. If we evaluate that perception with the same research we hold dear, I think we do find that perception is objectively incorrect. And at least for me, I think that perception is created by the subjective praises of Amir of recent DCA products, and objectively there is no reason to think DCA is more compliant to science than any other manufacturer. As long as market demands it, manufacturers will naturally, and rightfully, comply to whatever people are willing to pay for. That is our current economic model.

Final note, I am not saying this as a criticism of DCA. Regardless of their preference scores, their headphones might be amazing, I am not disputing that. And I am quite curious what would be the preference score for Caldera as well. I am saying all this because I think as fellow members of ASR you would also value the ability to evaluate your subjective perceptions objectively, and to see whether there is any factual truth in what we take for granted or not.

 

[IAtaman]

I have no affiliation with any company, Dan Clark or otherwise. As noted, they are one of the few companies producing high-performance Harman compliant headphones so I quote them. I wish there were a lot more examples and if so, I would be citing them especially if they were at lower cost.

Maybe they are not, and maybe there are more examples as well.

I am not sure how you are evaluating compliance to Harman research, I suspect it might be based on the FR's general compliance to the target FR curve? But, if my understanding is correct, that does not drive preference according to the research on its own, does it? Preference score calculation also has the absolute slope of the error curve in it too. My interpretation of that being : if you maintain the overall balance of darkness vs brightness, people might still prefer it despite having variations from the curve. Is that incorrect? If that is correct, wouldn't the preference calculation be the objective way to evaluate compliance?

 

[solderdude]

Are they really exceptionally compliant to the AE target?

I was curious, because I do have the same perception - but is that true?

As far as I am aware, there is a way to quantify an AE headphone's compliance to the findings of the research : calculating its preference score. I am not claiming it is perfect, but it is what the research suggests. Amir does not do that calculation, but Oratory1990 does. So based on his calculations, here are the scores for current line-up of DCA headphones and their preference scores. (if there are any errors in selection of which headphones are the current line-up, or any clerical errors, those are all mine)

View attachment 334428

Expanse and Stealth are probably in the Excellent category according to the research but the rest are just Good. And if we were to calculate an average based on this list, it would simply be just Good.

For sake of comparison only, here is a look at some of Hifiman's most popular headphones, again from Oratory's data.

View attachment 334427

All of them are Excellent as per research. Admittedly, this is not the full line up, and not all Hifiman headphones would score high probably. There might be a selection bias here as well, in the form of what I know of Hifiman are the ones that have high preference score probably. Nonetheless, looking at this table one can also make a strong argument that if a manufacturer was to be called "most compliant to headphone science", that might as well be Hifiman.

Again, for sake of argument, even Meze, which is not known in these circles as "scientifically minded" are not doing too bad. In fact, for their current line up, their average preference score would be higher than that of DCA.

View attachment 334429

So, you and I, and many other ASR readers probably, if asked would say DCA is the most "scientifically minded" manufacturer, and they do manufacture headphones that are inline with the scientific research. If we evaluate that perception with the same research we hold dear, I think we do find that perception is objectively incorrect. And at least for me, I think that perception is created by the subjective praises of Amir of recent DCA products, and objectively there is no reason to think DCA is more compliant to science than any other manufacturer. As long as market demands it, manufacturers will naturally, and rightfully, comply to whatever people are willing to pay for.

Final note, I am not saying this as a criticism of DCA. Regardless of their preference scores, their headphones might be amazing, I am not disputing that. And I am quite curious what would be the preference score for Caldera as well. I am saying all this because I think as fellow members of ASR you would also value the ability to evaluate your subjective perceptions objectively, and to see whether there is any factual truth in what we take for granted or not.

It's why I think calculated, as well as 'subjective' scores from a reviewer, are totally nonsensical and should be discarded if one wants to select a headphone.

Of course the data is there (accurate or not) and opinions are there (we all know what they can be like) and one can use that... but... a single number or ranking ?

Yes, measurements are based on plots made on a specific test fixture and most likely with ideal circumstances and is 'applied science' but I would not call this number generation 'science' at all if it has to mean something to a consumer looking for a headphone.
Some people just like lists and rankings for them this is a blessing and consider that 'science'.

The (sad?) truth is that not everyone has the same preference as that silly number and there is more to headphones as merely 'FR on a standard fixture' alone.
Comfort, fit and for some weight, are also important. Regardless how great a headphone sounds if comfort/fit are poor no one wants to wear them for a longer period.
And comfort, weight and fit is also highly personal and not included in that silly number.
Even Dr. Olive states that scores that deviate 10% says very little.

Nah, preference is personal and may not adhere to the formula and test fixture results (a single trace one ends up with).

Arguably both the Caldera and DCA are both comfy and the fit is excellent but weight could be an issue.
The sound signature of the Stealth, E3 and Expanse with perfect seal and positioning just follows an overly smoothed target on a specific test fixture more closely than the Caldera (in a particular configuration).
Arguably the response (not even if it follows a target) of the mentioned DCA models is 'smoother' which usually (but not always) points towards higher sound quality regardless of the tonal balance.

Someone's personal preference may well deviate from that that fixture and averaged tonal response. We have to learn to live with it.
This all does NOT contradict nor invalidate Harman research even in the slightest sense.

A 'majority' is just a numerical subset of 'all' and means there is also a minority and there is a sliding scale where at certain points the 'majority' number is abandoned.

/rant

 

[amirm]

Preference score calculation also has the absolute slope of the error curve in it too.

I do not use preference score even with speakers where it is more reliable than headphones. I evaluate compliance with both eye and my reference speakers.

 

[IAtaman]

It's why I think calculated as well as 'subjective' scores per reviewer are totally nonsensical and should be discarded.
Yes, they are based on plots made on a specific test fixture and most likely with ideal circumstances but I would not call this number generation 'science' at all.

The sad truth is that not everyone has the same preference as that silly number and there is more to headphones as 'FR on a standard fixture' alone.
Comfort, fit and for some weight, are also important. Regardless how great a headphone sounds if comfort/fit are poor no one wants to wear them for a longer period.
And comfort, weight and fit is also highly personal and not included in that silly number.

Nah, preference is personal and may not adhere to the formula and test fixture results (a single trace one ends up with).

Arguably both the Caldera and DCA are both comfy and the fit is excellent.
The sound signature of the Stealth, E3 and Expanse with perfect seal and positioning just follows an overly smoothed target on a specific test fixture more closely than the Caldera (in a particular configuration).

Someone's personal preference may well deviate from that that fixture and averaged tonal response. We have to learn to live with it.
This all does NOT contradict nor invalidate Harman research even in the slightest sense.

A 'majority' is just a numerical subset of 'all' and means there is also a minority and there is a sliding scale where at certain points the 'majority' number is abandoned.

I don't fully agree with what you said, I think there is a value in using statistical research on review of headphones. But let's leave that aside for a moment and dig into personal preference topic a bit more as I want to one-up your comment

Of all the characteristic of a headphone that affects preference, tonality is the easiest one to fiddle with in today's digital world, given that the distortion is well under control and there are no large and wide dips that needs to be boosted, or other cancellations or resonances. If that is indeed true, then I think tonality of a headphone is the least important parameter that drives preference - because if it fits well, seals well, performs consistently, and if it is comfortable and has good spatial qualities, no resonances or total cancellations, and if I can EQ it as my heart's desire, why do I care what is the original tuning? . I know you don't like digital EQ, but if we were to put that to a side, what would be your take on that?

 

[amirm]

If that is correct, wouldn't the preference calculation be the objective way to evaluate compliance?

If by compliance you mean good performance, then no. See the graph from the paper:

See the bunch I have circled. They all have the same objective score (around 60) but their subjective (actual) ratings ranges from 25 to nearly 80! I can do a lot better by eye than using the prediction model.

 

[amirm]

If that is indeed true, then I think tonality of a headphone is the least important parameter that drives preference -

Only if your entire suite of sources can be EQ'ed. If not, then you want a headphone that is at least close to target so that it never sounds bad.

 

[IAtaman]

If by compliance you mean good performance, then no. See the graph from the paper:

View attachment 334448

See the bunch I have circled. They all have the same objective score (around 60) but their subjective (actual) ratings ranges from 25 to nearly 80! I can do a lot better by eye than using the prediction model.

That is a bit misleading. Paper explains the outlier that sits at the bottom and provides a potential reason as to why they think it does not fit the predictor formula. Plus, the paper also says accuracy of the model is not better than ± 6.7, and they offer categories I mentioned in the previous post instead of absolute scores as a way to evaluate preference scores. But more importantly, those score do not only depend on variation from the curve, they also depend on the "tilt" of the variation. So yes, model is not perfect, the paper says that much as well, but if you are doing it by eye, you are not doing it objectively or based on scientific research. It is your opinion.

 

[solderdude]

I know you don't like digital EQ, but if we were to put that to a side, what would be your take on that?

With that you assume that al people use EQ. This, however, is not the case nor always possible.
I think the vast majority of consumers (and audiophools) do use transducers 'as they are'.

Yes, with EQ you can improve tonality, usually within limits but that is the only aspect EQ can be used for.

It's not that I think digital EQ is bad or that I don't like it nor even use it, I do use it.
What I usually question is the 'validity' of computer generated EQ based on some test fixture, with some target and perfect conditions for a single measurement (even when it is an averaged one).
People tend to believe that if that is applied they are actually listening to 'reference' sound. What's most amusing is that when people have 3 (different) headphones and all EQ them to the settings generated by their favorite measurebator still find the headphones, while tonally closer to each other, still differ audibly and sometimes even like a headphone better without EQ.

So... I am not against digital EQ at all, just question the validity of its 'blind' usage and assumption that a headphone is supposed to sound like the EQ'ed result.
in general, yes you can certainly improve tonality/sound quality with EQ. Regardless if it is analog or digital.

This discussion, however, does not really belong in the Caldera thread but in THIS thread

I am all for scientific approaches b.t.w. and Harman (and othes like Toole) research is important.
The research clearly shows there is a preference which applies to the majority of listeners (in near ideal circumstances).

A potential problem with interpreting this research is that if one happens to have near ideal circumstances AND belongs to the majority of people and thus prefers the tonality they feel validated in the sense that there should be no deviation from that target as they hear it that way.
The realization that not everyone has near ideal circumstances nor 'average' preference does not mean it is the only correct 'tonality'.

 

[isostasy]

No, that is what you think headphones are for. You speak in absolutes with your opinion, while telling others their thoughts are wrong. If you view a pair of headphones in that manner that is perfectly acceptable for you, and I would not tell you you're wrong. Please show the same courtesy and respect to my thoughts as well.

You can pick apart an analogy as much as you like, put words in bold or quotes, but it doesn't change that for me, it worked well. In fact, you reinforced my thoughts by your response more than changed them.

I'm speaking in absolutes because it's a fact that headphones are for listening to music! It's not just my opinion

If you think otherwise, for example that they are primarily to look good, then that's "gear porn". Incidentally, I'm fine with you having the opinion that headphones aren't for reproducing a signal (in this case music) but are for looking at, but in that case I wonder why you've come to a forum called Audio Science Review, which is primarily concerned with just that.

The analogy worked well because it told you what you wanted to hear rather than being viewed critically.

 

[isostasy]

Are they really exceptionally compliant to the AE target?

I was curious, because I do have the same perception - but is that true?

As far as I am aware, there is a way to quantify an AE headphone's compliance to the findings of the research : calculating its preference score. I am not claiming it is perfect, but it is what the research suggests. Amir does not do that calculation, but Oratory1990 does. So based on his calculations, here are the scores for current line-up of DCA headphones and their preference scores. (if there are any errors in selection of which headphones are the current line-up, or any clerical errors, those are all mine)

View attachment 334428

Expanse and Stealth are probably in the Excellent category according to the research but the rest are just Good. And if we were to calculate an average based on this list, it would simply be just Good.

For sake of comparison only, here is a look at some of Hifiman's most popular headphones, again from Oratory's data.

View attachment 334427

All of them are Excellent as per research. Admittedly, this is not the full line up, and not all Hifiman headphones would score high probably. There might be a selection bias here as well, in the form of what I know of Hifiman are the ones that have high preference score probably. Nonetheless, looking at this table one can also make a strong argument that if a manufacturer was to be called "most compliant to headphone science", that might as well be Hifiman.

Again, for sake of argument, even Meze, which is not known in these circles as "scientifically minded" are not doing too bad. In fact, for their current line up, their average preference score would be higher than that of DCA.

View attachment 334429

So, you and I, and many other ASR readers probably, if asked would say DCA is the most "scientifically minded" manufacturer, and they do manufacture headphones that are inline with the scientific research. If we evaluate that perception with the same research we hold dear, I think we do find that perception is objectively incorrect. And at least for me, I think that perception is created by the subjective praises of Amir of recent DCA products, and objectively there is no reason to think DCA is more compliant to science than any other manufacturer. As long as market demands it, manufacturers will naturally, and rightfully, comply to whatever people are willing to pay for. That is our current economic model.

Final note, I am not saying this as a criticism of DCA. Regardless of their preference scores, their headphones might be amazing, I am not disputing that. And I am quite curious what would be the preference score for Caldera as well. I am saying all this because I think as fellow members of ASR you would also value the ability to evaluate your subjective perceptions objectively, and to see whether there is any factual truth in what we take for granted or not.

Also DCA and ZMF both started out modding Fostex T50RPs. ZMF has continued releasing various headphones with a focus on exotic woods and having different products with different tunings. DCA has clearly attempted to move towards targetting the Harman curve as time has gone on, however, with all 3 latest releases doing so.