I have a slightly different take on this whole subject -- and I'd be interested in your thoughts. I do agree w/ Tennis and others that
a larger percentage of the population enjoy music than the the pursuit of "audio" as a hobby.
However, I'm stuck on what exactly Tennis (and others) mean by "audio" in this instance. For me at least, it all started (way back in the mid-fifties -- my Dad's hobby of course ;--) and what excited me then, as now, was -- not the music itself (don't get me wrong, I love music, and have my personal interests) -- but the sonic thrill of performance; or an acceptable (to me) facsimile of a real performance ;--)
That's what attracted me most about "audio" in the beginning, and it still does today. I call it "sonic stimulation". There are probably thousands of powerful stimuli to which we humans are drawn, and creating an illusion using sound (as opposed to "listening to music") is just one of them. I think that explains why so many people can thoroughly enjoy music without needing the stimulation of a "re-created realism" which a good audio system can provide.
I've been assembling gear/systems since my late teens around 1958. And like most of us, changed and changed and changed everything! Over and over! But eventually, got to the point (about twenty years ago) where I achieved the kind of realistic reproduced performance that I found convincing enough to "sonically stimulate" me ;--)) every time I used my system -- and very little ot the hardware has changed since then.
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