I obtained about twenty midrange drivers on fleabay for $1.98 all! Yes, they had some blemishes. Yes, I had to pay shipping, but still, these were quite cheap speakers. The speakers are Foster, 25 watts continuous, 45 watts music. I arranged the midranges eight per side with power tapering and resulting impedance of 6 ohms.
I used LineSource tweeters, six per side, no power tapering, as close to each other as possible, with resulting impedance of 6 ohms. After first listening tests I decided to use super tweeter (Cervin Vega horn) in the middle. It sounded better that way.
Since the line arrays are quite sensitive, I had to use two woofers per side. Woofers are two 15" per side in parallel, wired for 4 ohms, to help raise sensitivity. Woofers do not go as deep as I would like to, but they match the sensitivity (and they were cheap).
Whole system is bi-amplified with tube amp powering the midrange/tweeter section and solid state receiver powering the woofers.
These line array speakers sound great, they are dynamic, very much like live music, they love the power. They do not suffer the constipation of normal speakers when pushed hard. Its the woofers which run out of pace first. At normal levels speakers barely move, so the speakers sound very clear and relaxed. You can be close or far, you can hear them well. I can be anywhere in the room, yet I can hear great soundstage. I like line array speakers. I can hardly imagine how they would sound if high quality drivers were used (like those in Genesis).