You have nailed the paradox. There is no such thing as "the sound of a flute." There is only "the sound of this flute, played by this flutist, in this room." And, getting your listening room to sound even close to any other room on the planet is a physical impossibility.
So what to do? First, let's dispense with the "sounds like a flute" standard. What that's really about is timbre, and modern audio systems, even relatively cheap ones, get timbre right, or close to right. What they don't get is ambience.
And, since the ambience of one space cannot be reproduced in another space, what's really going on is something the literature biz calls "willing suspension of disbelief." In other words, it's not that we are recreating the sound of an orchestra playing in Carnegie Hall. We are creating an illusion that makes us feel like we are listening to an orchestra playing in Carnegie Hall. And that illusion may be a long way from "the real thing" or, for that matter, a long way from accurate in the technical sense of flat frequency response, etc.
I'll probably get some flames here, because I'm really arguing that an audiophile who says, "My standard is the sound of acoustic instruments in real space" is fooling himself. That standard is impossible. But it's ok, because "fooling yourself" is exactly what you are trying to do. If you get a sound you like, if it lets you close your eyes and visualize your favorite concert hall, then you've really achieved something.
So what to do? First, let's dispense with the "sounds like a flute" standard. What that's really about is timbre, and modern audio systems, even relatively cheap ones, get timbre right, or close to right. What they don't get is ambience.
And, since the ambience of one space cannot be reproduced in another space, what's really going on is something the literature biz calls "willing suspension of disbelief." In other words, it's not that we are recreating the sound of an orchestra playing in Carnegie Hall. We are creating an illusion that makes us feel like we are listening to an orchestra playing in Carnegie Hall. And that illusion may be a long way from "the real thing" or, for that matter, a long way from accurate in the technical sense of flat frequency response, etc.
I'll probably get some flames here, because I'm really arguing that an audiophile who says, "My standard is the sound of acoustic instruments in real space" is fooling himself. That standard is impossible. But it's ok, because "fooling yourself" is exactly what you are trying to do. If you get a sound you like, if it lets you close your eyes and visualize your favorite concert hall, then you've really achieved something.