In the fall of 2010, I was driving the kids to choir practice, and I saw a bunch of public-address horns and drivers sitting on the curb. I pulled over, hopped out of the car, and asked the man raking leaves whether he intended to be giving away the gear for free. He said he was, so I wedged it all into the back of my van and got glared at by the kids. I was now in a position to wheel-deal myself into a LeCleac'h system. I sold two of the horns and one of the drivers, along with a bunch of other old gear.
Step 1: 800-8,000Hz: Azura AH-425 Horns
Once I had the money together from the sold-off salvage, I immediately ordered a pair of his AH-425 horns, which were designed for the remaining pair of salvaged Altec 288C drivers.
The horns simply bolt onto the drivers, so there's nothing to "build" here.
Those drivers on those horns cover (conservatively) around 800Hz to around 8,000Hz, so I still needed to cover 30-800Hz and 8,000-20,000Hz:
(The photo for this step is from Martin's website.)