How do you know when a stereo sounds good?

Well, if any question begs a tautological response, this is it.

A stereo sounds good to me, when it sounds good to me.

A stereo sounds good to you, when it sounds good to you.

It doesn't matter how one interprets the questions posed (whether "you" was intended to mean "one", or "me" as I read the question, the answer is the same). I've heard any number of systems that the owner was enthralled with, but sounded pitiful to me. In none of those instances was either of us wrong.

If the questions were intended to ask for a differential comparison, that's a very different matter, but also subject to the same preferential differences.

I would say, however, that if you cannot enjoy good music on even a mediocre system, it's not just the music you're interested in, or you have a very different understanding of music than I.  I fully enjoy listening to music in my Westy Vanagon, although it has the acoustics of an F2 tornado at highway speeds. I've flown >1M miles listening to Bose (or worse) headphones in horrendously noisy aluminum tubes, and enjoyed thousands of hours of music. I feel sorry for folks who can't enjoy the beauty of music if the decay of a cymbal isn't perfectly reproduced, or the "midrange" isn't perfectly liquid. Is it *more* enjoyable with better sound in a better acoustic? Sure, it can be, that is why we're here, theoretically.

But, I can be, and have been, brought to tears on particularly beautiful and soaring female vocal lines with mid-level cans on Youtube. If that's impossible for you, then I think you're missing an important part of the beauty of music. Mediocre reproduction of beautiful music is still beautiful. Beautiful reproduction of crap music is still crap.

That's just my opinion, of course, and it's totally impervious to the approbation or denigration by other's differing opinions.

@cindyment

"So since this is a free marketing posing as a question, I will respond with a

Do you have a suite of measurements that removes all shadow of a doubt that you are getting good sound, sound that you enjoy?

The answer is yes, yes I do"

For the record, I don't have a clue who "Ted" is, and being an old curmudgeon, this is as close as I get to social media, thus I'm more likely to invent time travel than get into FB.

BUT, here I would have to disagree with you. I would submit that don't know *that* the sound is good, nor that it *is* the sound you enjoy (although closer on this one) because of measurements. You've identified a number of the *whys* you find you're subjectively enjoying good sound. An example, say you tilt your system response to accommodate a loss of HF hearing on my part; that tilt makes your system sound wonderful to me, and shrill and unlistenable to you.  That's why I make the distinction - measurements can control, they can distinguish, they can provide for reproduciblity and repeatablity of particular setups, identify room modes, etc. They identify the "whys" for an individual, not as a general principle, because individual preferences are not determined (measured by, or identifiable by, are not the same IMO) by objective criteria. This may sound like a quibble, but believe it's fundamental to understanding the issue. You need no understanding of acoustics or physics to determine what sounds good to you. Serendipity can work, like the lottery. But you do need them to understand the parameters that combine to create the sound you prefer.  Audiophiles that poo-poo DSP will nonetheless experiment with all manner of pathological cable designs to achieve, less reliably, less predictably, and more expensively, what DSP easily achieves - i.e. what it is designed for.

And of course, when one makes an extraordinary claim that has no known support in either acoustics, electronics, or physics, one needs measurements to support the claim.  Yes, rocks, plates, firehoses, I'm looking at you...

@mahgister 

"Is my system better than the system of Ted or cindyment ? No

But it is so good i dont give a dam about upgrade... My system is under 500 bucks... All my device are homemade..."

This I would wholly agree with, it's where I am as well albeit more expensively, but to my thinking, you have made a diametrically opposing comment below:

"Feel free to contradict me...

A system does not sound good because we feel it is good.... A system sound good with minimal acoustical settings... If not it is an happy illusion... All my system were bad all my life and i always tought that they sounded good..."

OK, so please explain how is "because we feel it is good" qualitatively different than "But it is so good i dont give a dam about upgrade"?  You seem to be using "good" extremely liberally, meaning anything from "meh, sort of ok" to "so wonderful improvement is irrelevant".  So not sure exactly what you mean (I know English is not your mother tongue, and I'm not trying to quibble grammar or syntax, just not sure the distinction you are trying to draw). 

I would also say that "If not it is an happy illusion" applies to all stereos at all times. Stereo *is* an illusion, is just the realism provided by the illusion that we are discussing. There is no one "True Path" to enjoyment, there are a great many, and they are far from universally shared.

@cindyment 

Ah, OK, you said:

"I have a suite of measurements that ensures I am getting good sound, but I would need to slightly reword to "and enables me to achieve sound I enjoy"

That was my point exactly. The measurements do not define your ideal, or preference, for what "good" or "enjoyable" are, they are an objective means to adjust to get that sound, and to get it reliably.  Phrased the other way I think it says it somewhat backwards, and is interpreted by "pure subjectivists" as *only the measurements matter*. See it all the time. When in fact the opposite is true.

I spent a number of years running a metrology lab...I like measurements 😁

@mahgister 

You said:

"But now i know why my system is "good" because i had a comparison BEFORE and AFTER these embeddings controls installation WITH THE SAME GEAR...

Then thinking that our sound is "good" is not enough now for me generally speaking ... We must know why....Thinking that good gear will do is not enough...Because of  the huge impact  of electrical noise floor problem, vibrations, and acoustic..."

OK, I understand what you're saying, and I agree on the importance of maximizing the acoustic environment (although not all cohabitants may agree).  And certainly, unless you are immortal with plenty of time to kill, understanding the underlying principles is absolutely important. But I don't see that as being responsive to the OP's question, as I read it. You appear to be addressing improvement of any given system, versus whether the sound is good and enjoyable as-is, which I take to be the original question.

As you say, you had a system that sounded good to you, so I assume you enjoyed it, if you enjoy music (which I take as a given). It seems to me you are saying more that you were not *satisfied* with the system, even though it sounded good, or at some point you became dissatisfied with it, so you're enjoyment declined. But again, I would say that's a different question.

You appear to be satisfied, once again, and again love your system. I'm at that point as well - I could improve my system, without doubt, but that would come at an expense (not just money) that is higher than it's worth to me.  It's at the point now where I'm far more disappointed with quality of individual recordings than with any "fault" I find in my system performance. 

And to forestall @cindyment, yeah I could likely make many of those poor recordings sound a bit better with DSP, but dynamically squashed recordings are never going to sound wonderful - except in the car!

Enjoy the music...

@noske 

@khughes The twisting of words by folk who eschew measurements sometimes makes my head hurt.

Since you only quoted/referred to me in that response, I certainly hope you are not putting me in the "eschews measurements" bucket? 

@mahgister 

Why people want to reduce everything to a binary distinction?

It's not really everyone who does that..

measurements are tools and necessary even for experiments...

There is a large cadre, however, that adamantly denies this simple reality. They self segregate, no need at all for me to do it for them.

But in audio our sujective experience is also primary...

Whether this is true or not depends on how you're defining "primary".  If, for example, I give you 2 identical power cords, one with a red plug, one with a blue plug, and your subjective impression is that the red plug is clearly better as it sounds more <insert audiophilic mumbo jumbo> than the black one. Now, that may in fact be true, but it's not due to the change in *auditory* stimuli reaching your body.  Should you rely on that subjective evaluation even when I tell you that the black plug cord is $10 and the red plug cord is $12K? I sure wouldn't.

As I replied earlier to @cindyment, in slightly different terms, correlation of measurements, a priori, to preference or enjoyment is not trivial, if possible at all. But measurement of *difference* is trivial IMO. So, if there's no scientifically known mechanism of action for A (latest floobie dust product) to act differently than B, in situ, and you cannot measure a difference between them in any relevant attribute or parameter, listening for a difference is folly.

Certainly any product can be designed to sound different, and do so, whether active or passive device.Those differences are easily measured as well. Because... if you don't know what to measure, or how to measure it (a couple of favorite disingenuous locutions favored in the snake oil world), however did you *design* it in the first place?