Hi Roger,
Thanks for going to the trouble of digging up those frequency response curves!
And apologies in advance for this reply probably being a lot more geeky than necessary... and please remember, this is me listening with my eyes!
In general the ear tends to hear broad average trends, rather than focusing on nasty-looking little peaks and dips that the eye is drawn to. In general peaks are more audible than dips. And somewhat counter-intuitively, "flat" actually sounds too bright (like there's too much top end), while a gently downward-sloping curve (like the Revel has) tends to sound "flat" or neutral.
Imo the dip in the middle of the Evoke 50's curve is wide enough to be audible, BUT my guess is that rather than sounding like the upper midrang/lower treble is lacking in energy, it may well sound like the top end has a bit too much energy, particularly if your room is highly reflective.
Something else that I try to take into account is what's happening off-axis, and the crossover between the midrange and tweeter on the Evoke 50 is 3.5 kHz. Since a 1" tweeter has much wider dispersion (at least down near the crossover region) than a 6" cone, we can expect a lot of extra off-axis energy in the same region where the on-axis response is rising back up after that dip. In my opinion this is not a good thing; my preference would be to actually have an on-axis dip at the bottom end of the tweeter's range, to sort of "balance out" the extra off-axis energy in that region. So, listening with my eyes, I'd take the Revels or the Amphions over the Dynaudios.
Here's Soundstage's measurement page for the Amphions:
https://www.soundstagenetwork.com/i...&catid=77:loudspeaker-measurements&Itemid=153
My eyes can't help but notice that 750 Hz peak; the 150 Hz jog is almost certainly a port resonance artifact present in the Argon 7 which will not be present in the Argon 7LS (which uses a passive radiator). I looked at a bunch of online commentary and found nothing that could be attributable to issues in the 750 Hz region. The worst I found was someone who wasn't impressed with them at an audio show, and said they sounded boomy. He also said an open-baffle speaker at the same show sounded boomy, so I'm inclined to blame the hotel room.
Overall the Amphion's on-axis response is pretty good and I like the gently downward-sloping trend of its "listening window" curve, but what really stands out to me is its off-axis response. Look at the off-axis curves, in particular the 45-75 degree curves, and note how smoothly they fall off as we move off-axis.
Here is Soundstage's measurement page for the Revels:
https://www.soundstagenetwork.com/i...&catid=77:loudspeaker-measurements&Itemid=153
The Revels have superb on-axis response and "listening window" response, but in the 45-75 degree off-axis curves you can see that there is excess off-axis energy at the bottom end of the tweeter's range. Actually this trend is present in the 30-degree curve as well but it's harder to see because those curves overlay one another somewhat. To their great credit the Revels don't have ANY problematic areas, aside from the increased energy off-axis energy which starts showing up around 1.5 kHz and peaks around 3 kHz, and this is normal (though imo undesirable).
Just for fun, glance back at the Amphion's off-axis curves and see if you can easily tell where the crossover is. It's not at all obvious! This bodes well for both coherence and long-term enjoyment.
What we hear is essentially a "weighted average" of the first-arrival sound and all of the reflections, with the earliest reflections mattering more than the later ones. The earliest reflections will be from well off-axis, from the floor and ceiling and side walls. The off-axis curves give us the most insight into what those early reflections are like. Ideally they sound very much like the first-arrival sound, but not as loud, and typically with a bit less top-end energy. The Amphions do this very well. In my opinion this matters a lot, but I am in the minority - most designers do not give high priority to what's happening off-axis.
So imo this is a classic case of each speaker doing different things extremely well, reflecting different design philospophies and priorities. I do not think there is a wrong choice between the two. I think both are designed for long-term enjoyment rather than for impressing in a quick audition, with the Revels probably being a bit better in and near the "sweet spot", and the Amphions probably being a bit better from well outside the "sweet spot".
Since you mentioned bass extension, it looks to me like the Amphions DO surpass the Revels in low-end extension, while the Revels have more upper bass energy. I suspect that the Amphions' bottom end + normal boundary reinforcement from a small-to-medium room = really nice bass response.
Kal Rubinson OWNS the Revels, which means that he voted for them with his wallet, and you can't get much more informed than Kal, nor much more sincere than a wallet-vote. Take his advice over mine!