When running dual LFT-8’s, the tweeter on one of the two speakers (per side) should be disconnected, to prevent comb filtering. The tweeter operates from 10kHz up, with a 1st-order high pass filter (and the midrange panel a 1st-order low pass at the same 10k). The wavelength at 10k is only 1.35 inches, much larger than the distance between the tweeters in two LFT-8’s placed side-by-side. A pair of stacked LFT-8’s is an interesting proposition, one on top of another rather than side-by side.
I have a pair of LFT-4’s, the half-sized LFT-6. And a pair of LFT-8b’s. I’d trade my two sisters for a pair of LFT-6’s.