Peter N,
Your inductor placement is good.
Brendan,
I'm a bit confused by your schematic. I do not see the series 0.1mH inductor on Zaph's schematic. Where did it come from? As far as the placement of the inductors go. I would try to separate the woofer and tweeter parts of the crossover (perhaps put the woofer crossover on the floor of the enclosure and tweeter crossover on the ceiling of the enclosure?) This would allow you to separate the inductors further to minimize crosstalk. As drawn, assuming the 0.1mH inductor is correctly included, I would be concerned about mutual coupling between the 0.28mH and the 0.1mH as they have parallel coil segments that are close together.
Regards,
David
EDIT: I should rephrase the "parallel coils" part of my previous comments. It is not enough to just make sure that the full coil diameters are not parallel. If segments of the coils are parallel (as with the inductors in your drawing) there will be coupling. The best case is where the inductors have no parallel segments as shown here:
[IMGHTTPDEAD]http://www.troelsgravesen.dk/coils_files/coils_5.jpg[/IMGHTTPDEAD]