Test Equipment vs The Ear

How does one measure soundstage height? Bass slam? Inner dynamics? Warmth? Presence? Musicality? Liquid-ness? Separation of instruments? Realism? The noise contribution of RFI/EMI? How do you determine that the "information" you’re hearing is all (rpt all) of the "information" on the recording?

I'd go with the EAR every time.

Often measurements are inversely proportional to sound quality.  Great measurements can be achieved by usage of deep negative feedback, that will introduce unpleasant TIM distortions, that we don't even measure.  TIM distortions were unknown until 70's.   Do we know everything today?  Shall we allow some TIM distortions to dramatically reduce THD and IMD?  

THD stands for "Total Harmonic Distortions".  What if "Total" is the same, but made of different sets of harmonics?  Do we know which "set" sounds better.  Some people like euphonic harmonics and without them gear might sound clinical/analytic. Warm sounding even harmonics can be wonderful with voice or guitar but might sound horrible with the piano recordings.

Everything at the end always comes to "How does it sound to you?"

@eoffkait - I immediately thought sound-stage (or image) also - but the others you mention are equally immeasurable - except perhaps for dynamics?

At present, dynamics can be observed on an oscilloscope and if plotted against X-Y coordinates and factor in time, one could come up with some sort of measurement - e.g. slope/micro-second perhaps?

If anyone out there is aware of a measurement for dynamic performance I’d love to hear/read about it - thanks :-)

But I still ask - why bother - when the ear is so much more convenient and adept at discerning so many sound quality "improvements"..

I think it’s just "human nature" to want to qualify everything as proof of superiority - especially when our hearing starts to fail us.

Like you - I trust my ears every time - I stopped reading specs back in the 80’s.

Regards - Steve

The problem is that human hearing is not very good - your dog is much better at it. The good news is that for most parts of the audio chain it is now possible to design and manufacture units that are better than what humans can reliably discern. The differences that are still there are inaudible, but sometimes still measurable (and different is not necessarily better). The second problem with listening is that conditions have to be carefully controled. Levels have to be matched within 0.2 dB, because the brain interprets louder as better. This can only be achieved with a proper volt meter. The third problem is that comparison has to be near instantaneous because the brain cannot remember sound for very long. Finally, there is that old devil expectation bias (requiring double blind testing).