Experience with RD75 and Neo8
I have some experience with BG drivers.
The Neo8 has some interesting characteristics, but also some that make it difficult to work with, particularly in a smaller design such as you propose.
Here are some plots on axis and off, mounted on a 2' X 4' baffle:
[IMGHTTPDEAD]http://server2045.virtualave.net/ttriff/Neo8MLS.jpg[/IMGHTTPDEAD]
In a longer line array, the on axis peak at 13 kHxz is ameliorated to a degree.
Used in singles, the Neo8 has very little vertical disperion at high frequencies (imagine trying to make a 6" dia tweeter - it would beam like a searchlight above 5 kHz), so the speaker would have to be a just the right listening height. In multiples in a line array, it is more useful and less critical of listening position, IMO.
The bigger B&G drivers make some truly wonderful midranges, say running an RD75 from 600 Hz to 5-7 kHz, for example. Stunning on classical music, to say the least.
Regards,
Jon