An interesting oldie from the 70s was the Rectilinear X(ten) 3 way but the mid range ran from 200 Hz to 8 kHz with a 2 " cone tweeter above that and a 10" woofer in a closed box below so an almost full range speaker. And interestingly the crossover was a series one not a conventional parallel design.
But I agree with lots of us that full range has too many compromises in cut off lows and highs and inability to play loud. But I do love the top to bottom integration. You sense there is no crossover.
Just a closing thought. Perhaps the best full range speakers are a few one way planars and electrostatics. The most wonderful being perhaps the Quad 63 which even could image.