Yes prof, the Quad 63. The Eminent Technology LFT-8b, with it's magnetic-planar midrange drivers reproducing 180Hz up to 10kHz without a crossover. The dynamic woofer and ribbon tweeter are employed below and above that (respectively) via 1st order filters. Then there are the SoundLab, Sanders, and Music Reference ESL's, the Magneplanars, and many other dipole planars. Can't forget the Linkwitz LX521.