@rauliruegas 

it’s true - I am ATC USA and do not want to hide that.   Previously I’ve worked for EV (their rep out of Chicago including OEM)and JBL (in charge of cinema and installed sound in the USA)and now ATC ( I’m the importer for both pro and hi fi for the entire US).  I have the privilege of being able to ask an engineer who does driver design for living what’s what.  My goal is as much for me as for my customer: the more you know the better, as most bad decisions in audio are made based on bad info or lack of info.  There is a lot of misleading info posted on forums - this is what motivates me to post, to represent a different perspective, to represent what I know to be true.

Brad

You’re referring to a boutique element of high efficiency drivers that aren’t representative of this segment. Low eff. drivers have their expensive iterations as well, and when you count in the typically larger size of high eff. drivers, bigger voice coils and more magnet material, not least from the more widely accessible pro sector, their pricing compared to low eff. "hi-fi" dittos is actually very fair. Most of these very expensive high eff. drivers are vintage designs of limited production, btw., and it’s not that the production tolerances here are somehow magically "tighter" to reflect and account for the higher pricing.

Tidbit: just going by specs the EV woofers of my main speakers share the 97dB and 22Hz Fs TAD numbers of yours (Fs 21Hz, "broken in"), and I’m guessing they’d have retailed for about 1/10 of $4,000.

@phusis I think the power handling might also be part of the difference in price. My speakers also use a set of field coil powered 15" units, hand made by Classic Audio Loudspeakers that seem well north of the $4k of the 1602s.

Being few of these designs are vintage, or so I suspect, it hardly reflects a strict need for a particular driver-amp type adherence. My guess is many like for horn-based designs to be "toned down" a bit (tubes generally would seem to do just that) so to likely please a former habitual exposition to less dynamically/transiently capable direct radiating and lower efficiency designs.

Horns were used in the old days because tube amplifier power has always been expensive so you had to get the most out of the power you had. The use of controls on these older speakers clearly places them in the Power Paradigm.

I merely implied that context is paramount, and moreover suggested that what you advocate design-wise could as well end up being refuted (i.e.: the ears being the most important and last "judge" of things), not necessarily to say some people wouldn’t like the sound of your amps, but that they may prefer a speaker-amp combo that goes contrary to what you recommend :)

FWIW I'm one of the few that see a direct line between what we measure and what we hear. I'm of the opinion that the implications of what the measurements are telling us are not well understood so people still trot out the old saw of our ears being able to hear things we can't measure. So I'm of the same camp as Daniel vonRecklinghausen.

Chat with legendary loudspeaker engineer Laurie Fincham ...

Mike

Moreover, the claim that high efficiency is necessarily and always bound to be attained "with a price," sonically speaking, is a fallacy.

Generally, high efficiency speakers have sounded unrealistic. What do the masses think of and come to conclusions when they’re thinking high efficiency? There it is, it can be attributed largely to bad actors like Klipsch, who’re all over the place and generally made plenty of flawed speakers with a couple of exceptions perhaps. It also seems like any other jester will come up with some horn speaker whilst tinkering in his garage, bring it to shows, etc and they’ve sounded stupid.

Nevertheless, when you buy a high efficiency speaker from guys who really know what they are doing, they seem to sound truthful. ...

Dear @ghasley : You say that prefers no negative feedback and maybe because you have a deep misunderstood on feedback amp issue but some of us can learn about in this link coming for a truly expert engineering:

whitepaper (sotaturntables.com)

He was designer in Analog Devices Inc: "

Several years? I was with ADI- designing a wide variety of ICs for almost forty years and was most fortunate to become an ADI Fellow and Senior Fellow.

I am not a free-lance engineer. I retired from ADI a few years ago and I design audio (and other gear) for fun and for free, "

Sometimes post in Agon and is a gentlemans that we have to listen and read him. But as always are other people that just never learned due to their own or audio sale agenda,  especially in electronics items.

R.