I did mention on the other thread that I did work for Adire and don't mind you mentioning it. Of course I haven't worked there is a couple of years but still am working the the speaker business at another company. However, I would think that this would help m credibility not hurt it, as I have had a lot of experience with these sots of drivers.
I'm not a hardcore engineering type and know more than some but an still in the "enough to be dangerous" category as well. I just think it is a mistake to come to conclusions about a particular technology or approach like LMS or XBL^2 from the particulars of a given driver and many times the dominant factors are the particular execution and trade-offs made.
A avalanche is essentially a Brahma and so isn't between a Tumult and 5400 at all. Tumult is is its bigger brother with significantly high power handling and stroke and BL but with somewhat higher inductance as well. The 5400 is something different altogether. There are some measurements of a Brahma 12" based ported woofer in Keith Yates "way down deep" article here:
http://www.ultimateavmag.com/feature...ay/index1.html
As you can see, it is similar to the Tumult with less output but also a little less upper end modulation distortion. Still, that inductive hump is there.
Klippel has real problems with a Brahma / AVA as these drivers as they are suspension limited enough that you can't get a proper BL curve fit. I don't think it will tell you what you're looking for and the distortion measurement approach is probably better.