To a point. Since you're interested:
-The Straight 8 crossover went through a few variations & ended up with an asymmetric 3rd order (3rd order electrical + Zobel on the midbass array, 2nd order electrical + a parallel & a series notch on the tweeter). Don't ask me what the acoustic slopes were -I didn't back-engineer it, nor would I think it fair to do so. That would be tricky in any case because of the next point.
-The Straight 8 was the last in a series of designs that they'd played with for the best part of a decade. The 1870 was used, with some damar coating + a couple of other tweaks IIRC, presumably to mechanically damp out a bell mode. However: as I understand it, at some point, the OEM making the 1870 changed the driver design without bothering to tell anyone. Going by fallible memory, the curvilinear profile went west, along with a couple of other things. Basically, it wasn't the same driver, and it was no longer usable. So the Straight 8 was retired, and I think they informally point people toward Clark Blumenstein's speakers now as he's nearby and also offers nice bamboo ply etc. plinths for Bottlehead kits.