I recently built MJK's OB speaker and am interested in adding a tweeter. I used the Eminence Alpha 15 A and the Fostex FE108EZ. I have a set of Tymphany BC25SC55-03 1" square frame tweeter from another project that I temporarily hooked in series to the full range driver just to see how this would impact the sound. There is no question that having this pointed to the ceiling added to the top end. That was a quick test and I removed the tweeter. I am hoping others have done something similar and can share with me the tweeter and crossover they used.
What about the Fostex horn tweeter range?
For example, the FT17H, for which the crossover circuit is given in its spec sheet:
https://fostexinternational.com/docs/speaker_components/pdf/FT17H_rev3.pdf
For example, the FT17H, for which the crossover circuit is given in its spec sheet:
https://fostexinternational.com/docs/speaker_components/pdf/FT17H_rev3.pdf