You may get a radically different total power response (especially if sidewalls are close by) if polar radiation characteristics are different too. And then there's the basic resonant frequency, power handling vis a vis crossover point, not to mention the sensitivity and crossover-shaping major contouring. Not rocket science, but to many of our ears damned close! There's a lot to be potentially learned here, and in addition to basic design literature I'd suggest you invest under $100 in an analog Radio Shack SPL meter (NOT the digital), a decent tripod, and a test CD with 1/3 octave warbles, like the Stereophile one, et al, and run some simple curves from 1k up to 20k both in the nearfield (to sort out the two tweeters), and at listening distance (2-3m is good) to get overall room response. As you learn you'll be able to first be able to "pad" the tweeter(s) to approximate equal sensitivity, and then perhaps futz with the series cap into it for adjusting crossover point and power response. It can get a lot more complicated than that (bear with me, guys), but at least you'll develop an appreciation for the art, and indeed perhaps arrive at a sound you'll really like. Just be careful to not bring the new tweeter in at too low a crossover initially if it's power-handling isn't up to the Paradigm's. Starting at a higher cross-frequency (either by using a larger value cap or larger resistor) will protect it; then dial it in to the vicinity of the Paradigm's, tweaking for your preference. On the third hand you might indeed find that REDUCING the resistor pad on the Paradigm's a tiny amount is all you want to get a slightly brighter response (!), and save yourself all this effort in buying other tweeters! After all, tweeter level is a very subjective decision at the manufacturing/voicing level. If there's a 1.0 ohm resistor on the OE tweeter you might try a 3/4 ohm or 1/2 ohm and be done with it for $2! Have fun.
