On top of whats already been said a speakers impedance and max spl can determine which one best suits your system / intent.
EDIT: As to your question about shopping from measurements alone. I think you can, because you will still choose a better speaker if you limit yourself to measured ones as opposed to limiting yourself to a few audio shops. We keep chasing the perfect speaker yet in reality these measurements have put us soooo far ahead of the curve that I think statistically you will do much better if you just were to use measurements alone.
@smallwonder - welcome to ASR! And a very interesting topic you've started here.
No two speakers measure closely enough,
in all the ways that impact perceived sound from a listening position in a room, to sound essentially identical. In the future that might change, but as of now that seems to be the case.
However, you've made it clear that you understand that and are interested in a hypothetical situation where different speakers
do measure closely enough in all those aspects.
My view is that
@dweeeeb2 's comment captures the best answer to your query. Room effects, sighted listening bias, and lack of consistent listening-comparison controls all make the auditioning of speakers at various dealers/showrooms highly unreliable and much less reliable than properly done measurements. Auditioning multiple speakers in one's own listening space avoids some of those problems, but others remain, especially if you don't audition all the speakers at the same time.
But cognitively or psychologically, a lot of people have a simple fear: what if I buy based on the measurements and then I get them in my room and I don't like how they sound? That's a very reasonable concern. Where I think dweeeb2 hits the nail on the head, though, is that in terms of probabilities we are more likely to end up with a speaker we like if we make a thorough, informed review of detailed, properly done measurements than if we go by short-term, uncontrolled listening comparisons, especially if those comparisons are done in different locations and/or at different times.
But I think as humans we tend to have a cognitive bias here: if we in-person audition 8 speakers and pick 1, we tend to discount the chances that one of the many other speakers we never auditioned would have been better - and we
really tend to discount the possibility that one of the other 7 we
did audition would actually sound just as good or even better in our room, day in and day out, over long-term listening.
Conversely, if we review measurements and order a speaker on that basis, I think we tend to be
very conscious of the possibility that another speaker might have sounded better to us, because we feel like
if we had only listened to both of them we would have instantly and unequivocally realized that. I don't think that's actually true, but intuitively it makes so much sense that a lot of people believe it.
So I think in our minds using measurements vs auditioning leads to
qualitatively different-seeming scenarios where our choice turns out to be wrong, and I think we give those scenarios different weights in our mind that don't actually correlate to the reliability level of each method of selecting a speaker.
