You might consider the PureAudioProject open baffle speakers. Their Quintet models feature four 15" woofers, with various modules for midrange/tweeter that fits in the middle. These modules include a horn option, a coaxial driver option and a couple full range driver options, including a Voxativ field coil option. They have a smaller speaker called the Trio, which features twin 15" woofers and the same array of midrange/tweeter modules. Another great sounding open baffle system is made by Cinnamon Audio--it uses an AMT tweeter and active, DSP-controlled woofers. To me, these are very good sounding systems.
Songer Audio makes a single driver field coil system that is also very good sounding. Another speaker I really like is the Companion model from Charney Audio. This is a single driver, backloaded horn system that is impressively full range for a single driver system. The offer a variety of choices for that single driver, including models from AER and Voxativ.
My favorite speakers are not regular commercial products; they are custom made horn-based systems from Deja Vu Audio (Vienna Virginia) that utilize some very old midrange compression drivers and horns as well as modern custom made woofers and tweeters. They make speakers from about $10k on up to who-knows-where. The better models use drivers from the 1930's-1960's, and horns from the same era. At their shop, they even have a massive Western Electric 16A horn with vintage drivers and modern woofers and tweeters (the horn is three years shy of being 100 years old). Fun stuff. If you can make it to the Washington DC area, this is the place to visit for out of the ordinary gear (they also make their own tube amps, linestages, phono stages and DACs).