The placement and implementation matter of course, but at some point it comes irrelevant. I couldn't define that point but it's probably higher than you think.
Also, there's the factor of the sheer size of the VC. The TC3000's is a big honking inductor. (Admittedly, there is another thing that helps explain the low-fidelity bass quality it offers: a very peaky BL curve.)
But overall I think you are on balance right: variation matters more than value, and at some point it becomes irrelevant. As to what that value is, the driver with the
highest normalized Le I've measured that I consider a top-level subwoofer driver is the old Oaudio TC2+ 15, at 0.84mH/Ω. However, I cannot think of a driver I've owned or otherwise measured with a normalized Le of between 1 mH/Ω and 1.5mH/Ω. More typical for drivers I find myself liking are values in the >0.3mH/Ω range. In my personal inventory that includes the Peerless 830500 (XLS12)*, JBL W15GTi, Exodus Audio Maelstrom-X Mk. I, and Aurasound NS10-794-4A/NS12-794-4A/NS15-992-4A/NS18-992-4A. (Yes, I like the Aura drivers just a little bit..)
*NOTE: Peerless's factory-spec is for Le is much higher than ANY third-party measured value; I'm using the average measured value - using FuzzMeasure Pro and the impedance jig in the manual - for my 5 XLS12's, which all measure virtually identically despite being purchased years apart. All are of Danish manufacture, not the newer Chinese ones, but I suspect the Chinese ones are just as good.
It really comes down to actual performance. There's a reason people like the RAAL, and not because it's some fad.
I don't know if that's true. I suspect it's rather less true than you think.
I know, but DI matching still doesn't address the issue of metal vs soft dome. Harman has shown almost an absolute preference for metal which implies there's some reasoning behind it.
Cite? I don't know if that's true.
That said, the big research-driven speaker companies such as KEF and the Harman companies have moved to all metal tweeters, so you may be right.
At any rate, midrange power response is much more important than diaphragm material.
it's what the perceptual research seems to show.
In one room, likely gamed to show that conclusion. (Harman makes mostly wider-dispersion speakers. They do great science, but they're also using it as a marketing tool. One shouldn't lose sight of that.)
I do think, as a rule of thumb, the smaller the room, the narrower the pattern the ideal loudspeakers for that room will throw.
Most narrow speakers have their baffle step around 7-800hz. It contributes to a big bump in power.
But typically sound power should start declining at 5kHz or so.
And of course it has to do with driver handoffs. A 1/2" tweeter necesdary for non tapering power response can't play down deep enough for a decent crossover, at least not at meaningful SPLs.
Fortunately, the supertweeter fad, which led to bad sounding speakers even from KEF and Tannoy, is long behind us.
The controls have to be in place... no very early reflections (10-15ms) so a large space is probablynecessary. ;;;;::No:: baffle step below 15khz. (even Pluto has a baffle step at 3khz)
IOW, conditions irrelevant to a domestic living room and practical loudspeakers.
Those of us who have heard systems EQ'ed to flat sound power know what they sound like. B-R-I-G-H-T.