Single driver vs traditional 3 way loudspeakers

@kenjit  agree, how whizzer cone , just piece of paper can be compare with High quality tweeters , This is Woo do. Basically whizzes cone   drivers was used  in all analog Tube amps and Pro acoustic in Cinema
How they widely used in High End is magic 

I’ve listened to several full range driver speakers and all have compromises. Either they are soft, or lack bass, or have whizzer cone artifacts. The Cube Audio Nenuphar look interesting with a 10" woofer and 3 whizzers.

PHY has introduced a 6" driver that has no whizzer cone and yet is extended and smooth at high frequencies. Its hard to get it to go below about 60-70 Hz, but at that point you can use a sub with it quite successfully. I recommend keeping the deep bass out of that driver- to make the highs right it has a very lightweight voice coil that simply does not handle a lot of power. But it is 96dB at 1 watt, so you don’t need a lot of power to make it work in most rooms.

I prefer keep it simple with as few drivers as possible, usually 2, but 3 can be good too.   One is OK but will always have limits. 

I prefer keep it simple with as few drivers as possible, usually 2, but 3 can be good too. One is OK but will always have limits. Reality aside, 1 is best  ideally at least.  
Bottom line is coherence is what holds my attention listening.  Various ways to achieve that.