Currently have the Titan 615LX. Something that is cool about the speaker is that I could potentially swap out mid-tweeter units for something else. I have never actually built a design with 1st order crossovers, so this got me thinking. I am imagining the 15" woofer to be crossed at around 100Hz to an 8" widebander (lotta choices here). I would then use my Hawthorne AMT700's to hand off from the widebanders. Might still have to use some impedance correction on the mid to make a smooth transition, which I can live with. The AMT700 is meant to be crossed at 700Hz with a 2nd-order filter, and has decent power handling so I won't esplode it. Would still need to sort out the optimal crossover point for those two. This would all be mounted on a double-thick OB panel that would stand on the big woofer cabinet. The goal is high efficiency woofer in a big box mated with dipole mid AND dipole tweeter on the OB panel. Thoughts?