I believe I've come up with a legitimate way to gain LSi clarity from the top end, while still keeping the SDA effect. I've conemplated in-wall SDA's, but this seems may be a little more effetive.
My theory only works for those SDA speakers that only have one tweeter, or where both tweeters receive the same signal(Sorry SRS, 1.2's, etc...). My example would utilize a speaker like the SDA2B's.
For this experiment, I would need a pair of the Vifa ring radiating tweeters, an appropriate crossover for the tweeters, such as the the ones used in the LSi's, and a set of SDA's unworthy enough to make modifications to.
I haven't worked everything completely out yet, but my initial plans would be to leave the SDA tweeter leads unattached, and utilize the new tweeter's crossover instead. At this point, the high frequencies would be sent to the tweeter, while the mid/low frequencies would be sent to the woofers. The speakers could then be bi-wired, bi-amped, or a jumper could be placed between them.
Calculations would need to be worked out for the final cumulative resistance, as well as the actual crossover point for the tweeter. Modifications may have to be done to put the tweeters in the original location, such as modifying the hole and making sure they are the proper disance from the enclosure itself(my understanding is that the tweeters protrude a little away from the cabinet to help with aural alignment).
I know this isn't a perfect plan, and may not even be worth considering, but I just thought it would be neat to try, regardless of the uselessness of it.