Well, in an ideal world you don't want any to pass through at all, but what there is will likely be confined to minor early reflections off the back-plate (disrupted by the spider, if present) & any lateral from the basket legs & cutout. The rest should be eliminated by proper damping of the enclosure. In practice, with proper attention to the box, it shouldn't be a significant issue or you'd see it in the form of cancellation nulls. Other unwanted box resonances modulating the suspension are more likely a cause for concern in my book, or at least I've always considered them so -if anyone has other experiences though, always good to learn from them.
The measurement baffle size is 1650x850mm and, yes, the smoothing is 1/12 octave.
You can learn about the measurement setup on this page:
Measurements and compare | HiFiCompass
Depends on the size and shape of the box, quite honestly. If it's large enough, not necessarily, especially if you have irrational / acoustic ratios. But most closed boxes require some acoustic damping, which isn't a tragedy. The downside is, some acoustic damping materials aren't as effective as they should be, in which cases, you can certainly get problems. But it's difficult to isolate this as a single effect since you've got completely different loads and polar responses at play.
There exists so many different schools how to get the cleanest output from a loudspeaker that all schools just can not be correct, it is sometimes hard to know what is correct or not. You seems to know more about loudspeaker design then most and i very much appreciate your posts, so thank you 
I like C90 much more despite its higher distortion [emoji846]. For me NBAC too much dry and non emotional.
. I see. It gets a fairly high rating, is it among the better ones ? (better meaning true to life).
Dang it, I wasn't suppose to have a paper midrange, but have to admit, does figures look really good. Satori MR13P-8(5") looks good as well. I wonder how the TX version will do.
So, to sum it up, looking at the graphs, I would place the drivers like this.
1. Scan-Speak Illuminator 12MU/4731T00
2. Accuton C90-6-724
3. Satori MR13P-8
I am dead set on using the Bliesema T25B-6, so that takes care of the top end, SBA's coming 7½” SATORI MW19TX-8 or the 6½ version (2 in series). That is, no matter, 3 different membrane/cone materials... lol
I wish that 12mu had better measurements, of course... Nevertheless, I like it very much and stopped on it for my main home loudspeakers.
It's a question of taste mostly. I built several Accuton based loudspeakers in the past and think, there is no way back for me.
