@khughes ,
I probably did not communicate well my intentions w.r.t. measurement, at least to remove all doubt.
The question was posed,
Do you have a suite of measurements that removes all shadow of a doubt that you are getting good sound, sound that you enjoy?
To which I would still answer yes, because the measurements "removes all shadow of a doubt". I am not guessing about whether noise, distortion, and any number of variables I can control are detracting from my potential listening enjoyment (I do worry about some variables I have not found a way to control). I know that objectively, within the variables I can control (and justify the money for), that the sound reproduction I am getting is about as good as I can expect w.r.t. recreating what is on the recording medium. With that as a starting point, I can explore all sorts of different ways I can modify the sound to increase my enjoyment, and I already enjoy it a lot. So yes, I would say 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". I could not achieve the latter without the former. I may get lucky and stumble on it, but the odds would be much lower.
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.
It does not sound like a quibble. It sounds almost exactly what I would write :-) So let's take some license here, and perhaps illustrate to others why I took my approach. Let's say you love the sound of your system with piece of music X, but Y never sounds right. If you are counting on your amp, speaker, maybe some room interaction, lossy cables, etc. to make X sound right, you will never make Y sound right. With DSP, you can push a button and make X and Y sound "right" or at least as best as possible for you.