I am truly on the fence about this topic. I of course want to get the best sound possible out of my system. We can all (probably) agree that there is a difference in what we hear between listening to a $50 receiver from (insert era here) and a $1000+ receiver from (insert era here). The electronicals and design used DO matter in what we hear and at some point we may even be able to quantify or attach a certain type of electronical to a certain type of sound. Like the topic of the warmth of tubes or harshness of digital music. The problem is saying that (I am not an electrical wizard...) "this graph on this chart here at this mhz" will absolutely make your music sound like a tin can... or like a bass trap or whatever. There are so many variables... it is like saying that the manufacture of oil paint with a viscosity of XX and oil from Indonesia vs. Russia will make a painting by Picasso look worse (or better). It is all our perception of the final product that decides.
SO, what on a graph or chart will tell anyone that something will sound good or bad? I read a lot in this post and see a lot of smoking gun type of rhetoratic, "evidence" that something is snake oil. What evidence? It is all opinion... all of it. Good or bad, sounds good, sounds bad... all opinion. If someone hooks up a DAC or AMP or whatever and decides it sounds good then it sounds good. Is a tube of $1000 oil paint going to make a better painting? Picasso used mostly house paint...
$50 vs $1000 receiver: I'd suggest that the audio performance is the metric we're looking for, not the price. The $50 receiver will almost always perform worse, true - but that's because the price point severely constrains the designer's/company's ability to engineer the receiver for maximum fidelity. And as
@Speedskater notes above, even this indirect impact of price becomes irrelevant when we're talking about components that cost very little to produce, like cables. Heck, there are even $50 DACs - or at least $100-$150 DACs - that folks would be unable to differentiate from a $1000 DAC in a blind, level-matched listening comparison.
The electronics and design
do indeed matter as you say. The question is, what exactly matters, and how much does it matter? If a company says their amplifier sounds better because it uses silk capacitors or a special op-amp, or discrete wiring instead of an op-amp, that doesn't mean their claim is automatically true. We can easily figure out if it's true, though, by taking measurements, which is what
@amirm and others on this site routinely do. So it's not like there's some huge mystery and we don't know.
As for correlating a certain type of electronics to a certain type of sound, yes, absolutely - we already can do that. But what you're talking about is trying to correlate certain electrical or electronic differences to audio differences that people say they hear, but which have not been subjected to rigorous blind testing. In other words, before you can start to try to figure out why two amps sound different, you first have to establish that they do in fact sound different. This is a crucial step that most audiophiles skip.
The "problem," as you identify it, is not "this graph on this chart here at this mhz will absolutely make your music sound like a tin can." The reason that's not a problem is because no one ever claims that. To the contrary, it's folks who
don't believe in measurements who make such claims: "these cable lifters produced immediate improvement in soundstage imaging"; "this power conditioner is the most important upgrade you'll ever make, massively improving detail retrieval"; and so on.
There are indeed many variables, as you say. But your comment here engages in a very common line of argument: you are sort of waving your hands and saying "there's so much we don't know," when in fact there's quite a lot that we
do know, and to frame the issue the way you are framing it, one has to ignore a lot of what we already know.
As for Picasso, the analogy there is to the
recording and production of music for artistic effect, not to the
reproduction of music. Different paint might make a painting look different. Whether it makes it look better or worse is up to Picasso and to whomever else looks at the painting. That's subjective because it's about art and expression. It's not about the fidelity of reproduction.
As for what on a chart can tell us that something will sound good or bad? Well, that depends in part on what you think good or bad sound is. But there are plenty of measurements that can tell us if a piece of gear is likely to reproduce recorded music well - that is, with maximum fidelity - or poorly - that is, with audible divergences from maximum fidelity. So for example poor channel separation or high noise or intermodulation distortion - or very low amplification power resulting in clipping at moderate listening volume - are all measurements that can be put on a chart, and that can tell us that we are likely to hear "bad" or compromised sound out of a piece of gear in at least some circumstances.
Finally, if someone hooks up a DAC or amp and decides it sounds good, it does indeed sound good -
but there are two crucial caveats there:
1. It might not sound good to someone else. That's fine of course, but a major point of measurements is that, unlike subjective listening impressions, they allow us to
communicate effectively about the audio performance of gear. If it's all subjective and you rely only on others' subjective opinions, then you're just shooting in the dark when you rely on their recommendations about what to buy.
2. The DAC or amp might sound good to you
when you hear it that time. But with purely subjective listening impressions, you have no assurance that it will sound just as good that night, or the next day, or three months from now. Human hearing is notoriously variable. Our hearing is more sensitive at night; our hearing is heavily impacted by our mood, what we're looking at, what sounds we've been subjected to or what environment we've just been in before we start listening; and so on. Of course our own subjective enjoyment is the end goal - but relying solely on our subjective listening impressions to ensure that we get maximal audio enjoyment over the long term is a weak strategy. Hence the value of measurements.