The Objective, Subjective & Dejected Thread

In my experience, this hasn’t been boiled down to a particular metric or dataset yet - and… I’m someone who genuinely loves data/measurements etc. To some degree I do understand that rankings like SINAD are visually compelling, and people want this to mean something because it gives them confidence in a purchase. People can continue to believe in this metric all they want, I’ve just never found it to correlate with ‘good sound’ past a certain point. This is a long-standing debate/question, but when it comes to amp scaling, for the stuff that isn’t broken or flawed in some way, I don’t think you can predict better or worse with those existing metrics or indices people are currently using.

With that said, I think there are two ways to think about this. One is that we’re not capturing the right data, which is possible but… I also think perhaps unlikely. The second way to think about this is to say we’re capturing the right data but not analyzing sound quality preferences in terms of the right things. So for example, you could have certain nonlinearities that reliably contribute to positive experiences. I think this is also more likely because at the very least we know that THD+N is not at all predictive of preferred sound quality the way FR is. So there’s no meaningful subjective preference there for ‘better measuring gear’ with sources the way there is with headphone FR. Sean Olive and co demonstrated that nonlinear distortion did not have a correlated negative effect on preference (while linear distortion was audible at a lower threshold). You can check out that paper here. So the question would be… are there any positive correlations? To that I don’t have the answer, but I think maybe.

But regardless, the point about potentially positive nonlinearities is one that some objectivists will hate, because they believe that amplifiers should do literally nothing but increase the volume. Personally I think that’s a bit myopic - in fact this was confirmed to me some time ago when I got to interview some amplifier manufacturers who were deliberately trying to conserve some nonlinearities for one reason or another. Mainly, they’re not even trying to design for anything that scores well on that ranking because they also don’t see the value in it from a sound quality preference perspective, although that may change soon enough for marketing reasons… which we’ve already started to see in certain places.

In any case, I imagine that if you did a study with a decently large panel, and you used the same headphones but different source equipment, you’d find that people would prefer things that don’t necessarily score as well on something like SINAD. There might be some agreement with that as well, but it wouldn’t be anywhere near the kind of ranking you see on that index. Instead, what I imagine you’d get is something that’s a bit all over the place, meaning that this is simply not a meaningful indicator past a certain threshold.

To your question about the DAC and how it performs, I have no idea. I used the Matrix X Sabre Pro - which coincidentally does measure well. But the bottom line for me is that if you’re looking for a metric to predict ‘scaling’, I haven’t found it yet - but it sure isn’t SINAD.


Here you go. Please enjoy this SINAD measurement and the complete lack of information it contains.

I prefer this…


Well, let’s be careful, just because drama may exist or be incurred from a certain discussion, that doesn’t mean there isn’t truth to be found. Again I think this is something that actually hearing the equipment in question can remedy. But it’s so tough because without a visual predictor or indicator, it feels like we’re in the dark, and just have to trust other people’s subjective opinions… And that causes me all kinds of anxiety haha.

I hope to one day have a more data driven answer to this.


And to this… the warrant that I have is that I listened to it and found that to be the case. I find measurements incredibly valuable, but they’re still not a substitute for actually listening to the equipment.


Precisely! When we finally pull the trigger on the desired headphone, do we just take measurements of it and sit and stare at them, or do we listen to music using the headphone? Even Floyd Toole said “a loudspeaker isn’t good until it sounds good;” and as most of us know, he’s a huge proponent of measurements. There is absolutely no substitute for actually listening for ourselves!


I’d argue that it’s a stronger baseline than making judgments on something you haven’t heard… I mean we’re literally talking about auditory experiences here. Having had the experience is sufficient justification for any report or expression of it. Whether or not that report is correct is a different matter.

To be honest, to me it sounds like you’re trying to justify a claim without having had the experience with it, and merely identifying datapoints that appear to support your premise (even though they technically don’t), rather than approaching any of this in good faith. Your accusation of circular reasoning here is a bit ironic…


Ah, yes this is the key. I promise I’m working on a better answer to this haha. But at the moment, this type of stuff is also why I’m not able to completely draw a straight line between measured results and my experiences. For FR and perceived tonal balance, we’re there in my opinion. But for the rest of the experience, there’s a lot to still be figured out.

I should also at some point make a video about THD, and why it’s not what people think it is. There are some very interesting counterexamples to what typical representations of that stuff suggest - like I have a headphone here that measures better than anything I’ve ever seen for its THD, but it’s one of the least detailed things out there, like categorically ‘low res’. And that’s even after it’s EQ’d to match my preferences.


I didn’t think I had dipped into this thread: The Objective, Subjective & Dejected Thread


I may be off base sticking my 2¢ in here, but I’m not certain that @Resolve and @FiveEars have the same internal definition of “scaling”. And that may be because it may be akin to Justice Potter Stewart’s definition of pornography – in this case, “I know it when I hear it.”

In my experience with the HD6xx, it – like no other headphone I’m familiar with sounds qualitatively better with better amplification. I’ve driven it from iPhone, iPhone plus Dragonfly Black & Jitterbug, Dragonfly Cobalt, iFi xDSD, and Schiit Lyr 3 (both using iFi xDSD in line out mode and from Bifrost2). In each case, as available clean power increased, the bass became cleaner and more extended, and the “Sennheiser veil” became more penetrable.

The 6xx never attains the clarity of some better headphones, but with a touch of EQ it can become very very good - and I prefer it for some music over better headphones. My HD-580, on the other hand sounds almost exactly the same no matter how much power I use to drive it.
The point of scaling however, at least in my perception, is made in that the 580 does not benefit immensly from moving from iPhone output (CD quality) to the same quality coming through the Bifrost 2. The HD6xx however when paired with good amplification will resolve better instrument placement, soundstage, and room acoustics.

I’ve tried not to get off track here, but am trying to ascertain if you both have the same definition and perception of “scaling”. I also regret that I don’t have a 560 with which to compare the 6xx, and instead am relying on a comparison with what I know in the same family.


It’s related to a comment I made in the 560S review a while back about it not ‘scaling’ as well for detail as the HD6* series. I think he was looking for a more quantitative or data-driven source for that, when in reality it was just my subjective take when comparing those two headphones off of a variety of equipment.


Yes, I gathered that, and read the quant-related content in your exchanges. And I suspect that your idea of “scaling” and mine are quite similar, in part because we’ve been here for a long time, and are comfortable with this forum’s relaxed take on objective/subjective. @FiveEars is new, and we all know that many fora and many manufacturers’ marketing departments are taken with numbers.

@FiveEars gets extra credit for using the term “evils of presbycusis” in a post. I’m sure he’ll fit in just fine here.


Yeah I also think people sometimes take my reviews to suggest I’m an objectivist - which I would be if I could directly draw a straight line between the measurements and my experiences, but because I can’t, I’m left having to also report the subjective stuff as well. But, because of the objective side of things that I do also like, it’s easy to think there’s a data-based background for the type of thing in this discussion as well.


I don’t think so. It’s certainly not what I mean when I talk about a headphone scaling with upstream equipment. I think more commonly that attribution among many audiophile circles comes from how much a headphone’s sound changes depending on the gear - or more specifically, how much better something gets with ‘fancier’ stuff. Again this is super unsatisfying to anyone looking for a more objective answer to this, as it is unsatisfying for me, but I also haven’t come across one yet.

But, as far as the trend goes, I do typically find that higher impedance or inefficient headphones fit this attribution more commonly than easy to drive stuff. It’s just that it would be a mistake to say that this is a sufficient condition for ‘scaling’, even if perhaps it’s a necessary one.

With that said, I’m currently comparing the SPL Phonitor X and the headphone output of the EX5, with a low impedance and easy to drive Focal headphone, and it’s very obvious which one sounds better. So in my mind there’s definitely something going on and it’s worth asking questions around different qualities that don’t show up in measurements or aren’t understood fully yet, even just on the amplifier front.


No. It literally means that the headphone sounds better as it’s matched with better amps. Not more powerful amps. Not better sinad amps. Just better amps. It is that simple, and your failure to comprehend the concept is amazing. For example: My HD650 sounds much better from the Stratus than it does from the Jotunheim. You can easily observe that the stage opens up, frequency extension is better, etc. All of that despite the Jotunheim being capable of delivering more than twice the power. My Radiance, however, doesn’t improve nearly as much. It scales less.

You could try listening to it. Sure, you can measure it too. Seeing as there are no omniscient measurement suites that can definitively quantify every audible aspect of quality in a device as it relates to human hearing, measurements seem like nothing more than an exercise in theory or a determination of basic functionality. If you listen to a truly horrible sounding amp or dac that measures quite well, is that actually a better reproduction of source material? Subjectivist or objectivist, the answer is no.

If this is an attempt to close the conversation, then I’m happy to disappoint. Your argumentum ad ignorantiam is annoying and self serving, not productive argument. (I’ll give you a moment to go Google that term, as I’m sure you did with irenic.)

At what point did someone convince part of the audiophile crowd that observation is an invalid method for evaluation? Even from a scientific standpoint, observation is used to collect and record data, to test hypotheses and theories. Observation is critical.

The single largest crime of ASR is that they have convinced so many that they can’t trust their own senses. I’m surprised Amir can drive a car - can’t trust his sight to see if that’s actually a roadblock, can’t trust his touch to know what the steering wheel is doing or how hard he is depressing the accelerator, and can’t trust his hearing to know if that’s actually a siren from a police car trying to investigate why there’s a pedestrian protruding from his windshield…

Your senses work. Let them.



I haven’t been tracking the entire conversation (I tapped out), but your take, and general common sense, is a breath of fresh air.


My view is that most audio and electric/electronic engineers never knew that perceptual experiences can be and are scientifically studied. I’m going to avoid “subjective” and “objective” as often loose and useless terms – people are mostly referring to perception science without understanding what’s already known in this field. Moderator please move the affected posts to an audio science thread.

All research of humans, including medicine, physical performance, behavior, learning, perception, etc. rely on hardcore and rigorous designs with careful observation protocols. This is because humans drift off task, fail to understand instructions, are subject to placebo effects, and subject to umpteen biases or personal preferences. Observational/self-rating data can easily go astray with so many pitfalls.

But reliable observations and self-reports are possible. Conscious self-reports are often the only viable test method, and result in “something is better than nothing” data. The data is wildly fuzzy by the standards of physics and electronics, but it’s used every day in product design and marketing research. See the smartphone near you for a product tested to death with these methods. They work in the space between pure double-blind and raw, random naive observations.

A couple generations of psychological research scientists in the early 20th century denied inner experiences and created the rigid Behaviorism approach to research. This model actually works well in narrow contexts, and answered some important question but then ran its course by the 1950s. Behavior (external measurements) is absolutely “not all there is” about people, and serious psychological research moved on to cognition and inner experiences by the 1960s.

The hardcore audio measurement crowd sticks to a narrow perspective akin to the Six Blind Men and an Elephant story. We can measure this and we can measure that so they are real, but we can’t measure wook so wook must be fiction. No, you just have to be clever and find indirect confirmation of wook. Triangulation of causal relationships by examining questions from several directions. This can involve reaction times, forced choices, just noticeable differences, and related methods.

Perceptual illusions show how humans are evolved animals with all sorts of hard wired biases and quirks. This means their characteristics need not parallel electrical/physical data. Audio illusions exist, and while the mechanics is understood the illusions remain strong.

To get out of the endless “objective vs. subjective” bickering in audio, bog-common perception research methods must become standard in addition to the traditional measurements.

Samples of human research protocols:


Thank you, Professor. I think you, @Resolve and @generic have the right of it here. I can affirm that when I was trying to explain what we mean by scaling, that the HD-6xx does scale, and that it’s not merely amp power, but also that amp quality is necessary to really hear the scaling effect. And that changing out DAC was one way of confirming this. I deliberately left out some chains that I’d tried that might raise other objections - such as no true line out from the Dragonfly series.

And @generic 's points about perceptual science are also on point.


While I am not getting involved in this discussion because it has turned into something that has nothing to do with the original discussion, I did want to just mention one thing in reply to:

While not everyone will agree, because there is not much everone agrees on in this life, I would say that this forum is one of the most willing in terms of being open to discuss all kinds of items without being extremists. This doesn’t mean that everyone agrees all the time, or even most of the time, but once we start going around and around in circles over the same thing, we just end up arguing for the point of arguing. This is not beneficial to anybody and certainly does not keep up the happy and easy going vibe we aim for.

Just because someone is a member of the “Core Team”, it does not mean that they stop being human beings with their own opinons, along with their positive and negative things. If you feel that someone has broken the rules or has attacked you, then there is a flag under each message that you can use to report the post and tell the mods why you are reporting it. As far as I am aware, the rules are for everybody and the report function also works for everybody, so, again, if you feel it necessary, hit the flag button.

This is not in agreement or disagreement with anything that has been said previously in this thread (or the other thread where the discussion stems from), it is simply to say that I, personally, have found this forum to be one of the most easy going forums on the web (which is the reason why I am here) but there are always disagreements. The positive route is to listen (or read in this case), make your point and move on. Getting stuck in the rut of arguing for the sake of arguing is not healthy for anyone, believe me, I am married and have kids :wink:


I don’t think the problem is that forum members have different opinions or that they express them. If we all agreed, this would be a very boring place to hang out. It’s how those opinions are expressed. It’s not what you say, it’s how you say it. And if your sincere intent is to change someone’s mind or at least inform them, then you need to phrase your points in a way that they will be received and understood instead of just reacted to. When you find yourself attempting to win an argument instead of making the other understand your point of view, you have lost the argument.

Communication is a two-way street. Just because you don’t consciously imply something doesn’t mean that my inference of it is invalid.

Frankly this was the most interesting discussion I’ve read here in weeks, if not months. We need to find a way to encourage this. Just because this forum is arguably the most easy going doesn’t mean we can’t do better.

Sorry for the rant. It’s still early morning here, my back hurts, and I’m feeling a bit frustrated.


Serious question, can you please point me to the top 2 substantive points raised by the various sides? I do appreciate healthy and informative discourse, and may have missed it - which I tend to do when it comes off as if the content was written as if the author thought he/she was paid by the word/syllable.