LOL. (BTW, did you ever decide that you liked the 2.4 as well as you had the 1.6?) As for me, I think my main "issue" with speakers is what I would call trust: Whenever I hear a speaker that makes a certain disk or piece of music sound unusually great, I typically find that it isn't telling the truth and will be correspondingly not-so-great on other music or disks (not saying the Harbeth is this way - I don't believe I've ever heard a Harbeth, and anyway I thought they were supposed to be fairly "neutral" as the saying goes). I feel comfortable that the Thiels are pretty reliable messengers which I can trust, but at the same time realize that there are certainly aspects of the sound that my (after all relatively modest) speakers aren't capable of fully expressing (mainly having to do with the rich body, physicality, dynamism, ease and sweetness of real music). But I can't, unlike many audiophiles, be happy switching speakers often -- I need a consistent point of reference, and besides I'm also a cheapstake who isn't pursuing the SOTA. I started building this system by choosing my Thiels in '97, and have only recently really begun to think that I (and the rest of my system) might be ready to contemplate taking another step, which if/when it happens I presume would be "for keeps" for even longer next time...
Anyhoo, I've been thinking about the midrange driver on that 3.7, and it's occured to me that it might well not be driven at the inner or outer edge of the diaphragm, unlike typical cones or domes. The coil former might be attached at the center point of the ring, midway between the suspension surrounds, giving the diaphragm added rigidity by taking the form of a "T"-shaped cross-section. This would make a lot of sense in combination with the radial corrugation of the diaphragm visible in the photos, and very possibly indicate the kind of lightness and rigidity implied by the high first resonance point figure quoted by Unsound. (Lighter than could probably be achieved if the center-driven diaphragm projected forward in a similar-sized semi-toroidal ring, partly because the former itself can be made very short with the flat diaphragm.) If the flat corrugated ring is indeed center-driven, that would be one explanation for why the compound driver doesn't use Thiel's shared voice-coil technology. The only thing about this conjecture is that the driver is described as being 5" in diameter, which would make for an absolutely prodigously-sized voice-coil width-wise, though presumably very shallow in depth.
Anyhoo, I've been thinking about the midrange driver on that 3.7, and it's occured to me that it might well not be driven at the inner or outer edge of the diaphragm, unlike typical cones or domes. The coil former might be attached at the center point of the ring, midway between the suspension surrounds, giving the diaphragm added rigidity by taking the form of a "T"-shaped cross-section. This would make a lot of sense in combination with the radial corrugation of the diaphragm visible in the photos, and very possibly indicate the kind of lightness and rigidity implied by the high first resonance point figure quoted by Unsound. (Lighter than could probably be achieved if the center-driven diaphragm projected forward in a similar-sized semi-toroidal ring, partly because the former itself can be made very short with the flat diaphragm.) If the flat corrugated ring is indeed center-driven, that would be one explanation for why the compound driver doesn't use Thiel's shared voice-coil technology. The only thing about this conjecture is that the driver is described as being 5" in diameter, which would make for an absolutely prodigously-sized voice-coil width-wise, though presumably very shallow in depth.