other bill

When the top octave is over-augmented, I would describe the sound as sizzly or bright. Sounds like you're frying bacon with some material and cymbols take on a loud "kuush" that feels like a pin driven through your eardrum. That's what sometimes happens on horn tweeters that already have a pretty bright top octave, when they are used with aggressive compensation. If you have to attenuate over 12dB, then it might be good to use a smaller value of bypass capacitor. This is particularly true when using a bright tweeter like the PSD2002 on a horn like the Altec 811, which is a combination that already generates a lot of on-axis energy in the top octave.

If you feel the ladies are a little harsh, then you may actually have too much in the midrange overtone region, from 1kHz to 4kHz or so. That would tend to favor a solution having more attenuation from R1/R2 and a bypass capacitor C1 that allows more energy in the top octave to compensate. On the other hand, if you go too far in this direction - having too much top-octave compensation - then vocals will not sound shrill but the high-hat will be pretty hot.

A neat thing you might do is to make a handful of different cable assemblies with different values of R1, R2 and C1. Having several pairs of pre-built tweeter cables ready to go makes swapping out different drivers and horns relatively painless - You can easily compensate for their differences and make changes right on the spot. Maybe go through the charts and make some of the standard cable assemblies, and that will make configuration changes easy.

I think I'd start with the standard cables (from the charts) if I were you, because I took some time to make sure they were optimally damped with the crossover and most compression drivers. But if you feel that you need an in-between value, you can put together some variants as well. At any rate, the R1/R2/C1 influence is probably the most noticeable in the circuit, so changes made here are usually pretty audible.