If you mean simple and cheap, here's one. The Foster wide band drivers are $3/ea from Madisound. I used 14 midwoofers per side because I wanted these to be outrageously tall. Twelve per side wired 4-4-4 or 3-3-3-3 would probably be more practical. The midwoofers were designed for an open back application and they run full range with no crossover. The tweeter requires a simple second order crossover and some padding. Nobody will ever confuse these with high end speakers, but they do have the sensitivity, soundstage and dynamics of a line array with overall sound quality no worse than the typical two way from a big box store.