They would be bolted to CD horns, so the top octive compensation would be a plus.

I know that the cap values change for a 16 ohm driver, but I'm a little hazy on what determines the nominal value the completed system presents to the amp.

Yes, I know I could just tack a 16 ohm resistor across the driver, but that kills the sensitivity.

Also, would it be possible to design a passive crossover (high-pass)
that could do the same thing- present an 8 ohm load, but have the 16 ohm driver inside?

Thanks

Larry