I'd like to build a pair of these speakers, the 2226 drivers are easy to find for short money on ebay, I was pondering a 4430 design but the drivers are much more expensive and harder to com by. I guess the only real difference is that the 4pi's really need a subwoofer? They roll off rather steeply at 100hz while the 4430's are pretty flat until about 50hz, at any rate, may I have a set of plans please?