Some of my favorite speakers over the years have used passive radiators, though they seem less common these days then back in say the 70's. Goldenear Aon3 is the current one I know of that I have heard and also thought to have top notch sound especially for the price. The combination of side facing passive radiator and folded ribbon tweeter makes these a quite unique design these days at a very affordable price worth auditioning. I've heard Tritons as well and was less impressed, but I suspect the problem was in the specific dealer setup I heard somewhere and not the speakers.
