I agree with some of the things you have said here. I was the one that mentioned turning art into science.
It was a good post as is this one.
The problem in my eyes, and in my limited technical experience, is where are the tools to measure ALL of the intricacies of music?
Measuring music does not lie in the gear used to record or reproduce the recording. That's a whole other discussion, but truly something that many people get confused with the gear of music playback. Once you are involved with the recording process, a whole new perspective takes place. Measuring art is an interesting idea best left in the Ivy leagues.
I know that you can measure frequency response, THD, wattage, noise, etc, etc; but don't these things just define the borders and not the entire picture?
There is much that can be measured, but there are a few that are extremely difficult that you mention next. Correlation of subjectivities relationship to the metrics is best left to psychoacoustic research. The unfortunate part is that the audiophile's vernacular isn't consistent and it creates difficulty b/c of the various interpretations. It really would be best if people read the research on the topic. There's no way I can sum all the research available into a post, and I certainly don't know it all.
What measures tonality, sound staging, spatial information, transient response, dynamics, etc, etc?
Keep in mind, this is not my profession and even among professionals much of this is debated b/c the definitions are not pinned down. It's a very subjective thing that you're asking for and thus difficult to create a single metric for. This may well bring on more flames(which is ridiculous behavior especially for grown adults), but what the hell, I'm in the mood to write in hopes to stimulate some thought. Keep in mind, this is not all inclusive and some of what you are asking has no direct metric--obviously or we would have a metric named "sound staging, spacial Information, etc..." This is a subject that could be discussed for days and days because lets face it, it's subjective. Anyway, here's my attempt to summarize what I think.
Tonality can be looked at from many different metrics, but basically a polar response and impulse response will tell you what you need to know. Some people would argue for phase as well, but the science refutes that claim.
Look here for a good explanation what tonality is:
http://en.wikipedia.org/wiki/Tonalityand you'll realize this is a music term, not a playback term. That said, wild polar responses will not have good tonality unless they somehow match the inaccuracies of the recording process--fat chance. If it does on one, it won't on any other. The recording process has as much to do with this as the playback. That's part of the reason why getting a polar response on a speaker is more useful than going and listening to your few favorite tracks. Rise time and Decay should also play a part and can be seen by looking at the impulse graph, CSD, wavelet, etc... With the impulse(s) and a polar plot, you'll have all that info.
What most people seem to describe as soundstage as far as I know mostly has to do with speaker placement and polar response. If you are shooting an even sound across your room and your room and your speakers are placed with the left on the left and the right on the right, away from the walls toed in, I can't see where you could go wrong. A narrow directivity should give you a better image where a wider, a better sense of space.
Spatial info is another one of those touchy definitions. To me that's mostly in low level detail resolution if you're talking about what's actually contained in the recording. IOW if you want to hear the recording environment as picked up by the microphone and diluted or enhances through the process of production. Which means anything that interferes with that can have an impact. So from the loudspeaker standpoint, impulse, cabinet accelerometer CSD, now it even looks like capacitor vibration(so there may well be credence to more tweaks like God forbid, cables! Nothing has turned up there yet that I know of), and polar response will play into everything. There are many things that can effect the low level resolution. I'd bet to some degree you can trace this all the way back to the source. This may be the most expensive, difficult and time consuming part to get to the "N"th degree.
Transient response is another one of those CSD, Wavelet, Impulse, polar. It's just rise time and decay. A CSD or Wavelet don't tell us a whole lot without the impulse response--ever really that I can think of.
Dynamics is another interesting topic that depends on wether you are talking physical or psychophysical. The best way to look at this graphically would go back to everything mentioned for transients, then also thermal capacity, power compression and efficiency.
Etc, etc... I know, no publisher of specs is giving you this information, so knowing how to use it or think of it is of little use. In the end we are all left to guess. I wonder if informed guessing is better than uninformed. I bet anyone schooled in the issues at hand could do much better than I. Every time I read something new, I learn more and I'm betting any recording engineer, acoustician, transducer engineer, etc... could do a much better job than I just did.
I think that evidenced based practice can be a valuable tool, and is very pertinent in objective cases where varying opinions do not effect the outcomes.
What are you, a doctor?
(that's a friendly joke based on that statement people) That's the nice thing about Psychacoustics. It gives us evidence from which to base our practice that's far more reliable than our non static subjectivity.
However, my point about art, is that music, and the reproduction of it, are so deeply seeded in subjectivity based on the nature of music itself, how can you hope to be able to objectively measure on a consistent basis what is true and untrue?
We really aren't trying to measure the music and that's where the majority of audiophiles get the most confused. We can measure a Picasso by the size of the painting, the array and tint of the palette, the size of the brushstrokes, etc... but that still tells us little about the impact of the painting on our lives. It may well have more impact if its viewed in better light. I like the music I like on any system, but more on my main system.
Nervously awaiting refutation,
Dan
