Didn't see this post until I just wandered around the site. So, I am as curious as you. FRX3? Kinda hard to tell how the specs might differ when I read about the two drivers. It will say one thing in one place only to say something close but not the same in another place. For instance, some photos of the driver FRX2 show a switch on the back of the speaker like mine had, but other photos do not have the switch, including the FRX3. Then when I look at the ZOB demo, the FRX driver shown there had no whizzer cone that I could see or even the obvious copper phase plug. In one photo the center of the speaker is not visible because of the mike in front of it. But the left speaker, though a bit out of focus is clear enough to see this.

Oh Oh, he's not using silver windings is he?

That would definitely be a step up from what was used in the FRX2. The beginning of the is transformer thing all started when Steve was adjusting for the shout in a Fostex driver IIRC. I loved this solution that he came up with and bought not only set of Gizmos of my own, but a pair of FRX drivers. W/o getting into the rest of the story, I ended up with FRX2 drivers that had a switch on the back for two different sounds from the FRX2.