accurate as it applies to speakers is a term I think that comes from the recording studio, and simply as far as I understand it to mean, means a flat amplitude response, or in other words, no portion of the frequency spectrum varies too much from the other

OR...sounds on reproduction like it was recorded.

it is by the latter definition a subjective and individual term, not absolute or scientific.

So you don't get a slightly louder mid wrt the bass, or a slightly emphasized treble.

Quite how this makes something 'sound' better is beyond me.

The idea is that it will give mixing and mastering engineers a better picture with which to do their job.

You absolutely cannot judge the way a pair of speakers or amps sound, simply by looking at the flat graph, and then saying..its flat, so it sounds better.

The frequencies are all in balance, but that does'nt tell you about string 'tone', brass 'raspiness', detail, breathiness, clear voice, all that.

ditto with an amplifier.

The only test if you love music is to find something you like the sound of.that is all there is to it.

the fact that some antique amps measure dreadfully, but sound wonderful is pure proof, sure its not wrong to try to improve figures, and better technically, that is progress and science, but to claim objective=subjective is nonsense, as anyone who has looked at graphs, figures,  and listened will know.

how we so complicate things.