Single driver speakers. Are they worth considering ?

@tkukielk,
Smart decision to have a high quality cabinet built. The premium tier Cube Audio F 10 driver deserves this level of attention. I’m glad to read that you’re very happy with the sound quality.  Congratulations!
Charles

Hi riaa, 
Looks aside, have you heard a Charney? If nothing else if would provide a nice context to compare with  the Nenuphar Mini. Congratulations on your purchase. 
Charles 

@vinylbrother, 
If the occasion arises for further listening to the Cube Audio speakers (Especially the 10" Nenuphars) please share your impressions if you do not mind. 
Charles 

@inna,
Ocellia and Tonian Labs are two brands that have used various size  PHY drivers. There were probably a few more. 
Charles 

Cal,
Agree .
The PHY-HP is a legendary paper cone driver created by the late Frenchman Bernard Salabert. The 12" version in particular is held in high esteem for superb sound8 quality. The Cube Audio Nenuphar is a very different design and approach which by all accounts extends deeper and goes higher than the classic PHY.
Charles

I recall hearing a very well implemented single driver speaker based on an 8 " Fostex driver at RMAF a few years ago. I was really taken with the sound quality. One of the better rooms of the entire show.

There are some inevitable tradeoffs but this applies to "any" type of speaker. Multi driver/Multi crossover speakers have their own set of tradeoffs. It is always a choice of what compromises can you willingly tolerate long term and be happy.
Charles

Evolution and progression does occur.  Someone's experience with a Lowther single driver speaker has little to do with hearing a Nenuphar or Charney. Faulty extrapolation. 
Charles 

For a very reasonable cost the Omega speakers (Especially those utilizing the Alnico magnet)  consistently received high praise for their natural sound quality.

Moving to a higher price point the Cube Audio Nenuphar has  been bestowed with excellent reviews by professional writers and outstanding owner feedback testimony. It could quite possibly be the pinnacle of upper tier single driver speakers,. Purity and convincing realism are repeatedly cited.
Charles