For use in the midhorn without the requirement for bass, there's a BIG difference between JBLs and the pressed frame Eminence drivers. The JBL is much cleaner. Eminence's Magnums are close, but they don't make a 10" driver. The neodymium Deltalite 10 is a good premium part with reduced HF breakup. But because of that, it rolls off about 1kHz in the midhorn, so crossover must be made sooner than with other drivers.

For an eight π, you really need electro-mechanical parameters like those of the Alpha 10.

The Delta 10 sounds very nice too, and it isn't expensive. The horn decreases distortion by reducing drive requirements, so even lesser drivers sound very nice and clean. If you're using the horn for midrange only, go with the Delta 10 instead of the Alpha 10. The Alpha is better when you're going to use a bass-reflex rear chamber for bass in addition to midrange output from the midhorn. But when used as a midhorn only, the Delta 10 is better.