I have a pair of Raal 20xr tweeters that I would like to try out in a home project. They are the multi tap/ sensitivity type. I have no equipment to measure their impedance and want a suggestion how best to attenuate their output to about 85-86 dB. They are unusual as about 3/4 of the crossover is designed into the actual tweeter leaving the user to use a capacitor to adjust sensitivity at a fixed crossover frequency of 1800 hz.
The taps are used to select the sensitivity. Using different taps presents a different load to the crossover. It takes a different value of capacitance to maintain the same crossover frequency on a different tap.. If you used a different capacitance on the same tap you'd change the crossover frequency, not the sensitivity.
If you look at the impedance it is not very difficult to work with. The first thing I would probably try is using a series resistor. This also means adjusting the factory specified capacitance to work with the extra resistance.