Single driver speakers. Are they worth considering ?

I have to agree with larryi2 on the Charney Audio Horns. Throw out every conventional negative knock about fullrange single driver speakers. Charney Audio horns are designed on the tractrix theory and deliver music that emotionally engage the listener. It’s all there, natural highs, enticing midrange, and proper well defined bass.

Not all single drivers are made the same "the better the driver the better the performance". This is true with a properly designed and implemented enclosure. I was very impressed with the inexpensive Lii Audio Fast 8 in the Maestro cabinet designed for smallish rooms. Voxativ drivers shine and AER are absolutely sublime! Detailed, fast, and accurate when mated with high quality electronics.

Full disclosure I own a pair of Charney Companion Horns designed for the Omega RS7 driver. Listening to them as I write this. I have owned a number of Omega speakers in the past. Louis does a great job and is an awesome guy to work with. But IMHO the Charney Audio Horns take the RS7 to a much higher level!  Hoping to upgrade to a Companion with Voxativ drivers soon.

Read about Charney and the tractrix theory here:
http://charneyaudio.com/

How about a pair of Omegas with a pair of monster subs?

I had the Omega Compact Hemp, Alnico Super 6 Monitors and Alnico XRS 8 all with dual Omega subs. Could never get proper integration until I used a Dspeaker Dual Core. The Dual Core helped to blend and manage the bass well but not perfect. I never used the X4 but have been told by others who own one, that it does a fantastic job. 

The best bass and sound top to bottom has been with my Charney Audio Companion Horns with Omega RS7 drivers. Charney doesn’t make the Companion with RS7s anymore. The Voxativ and AER drivers are so superior in every way. Hoping to unload my Companions soon and step up to the Voxativs. 

Charney released a new version of the Maestro to accommodate those with smaller rooms. 8” Lii Voxativ or AER driver of your choice and can be finished pretty much any way you might want. They have a more traditional squared off style with the horn facing the floor. BTW they sound incredible for what they are!! 
FWIW All of the Charney designs are made from wood. Void free Baltic Birch plywood, wood veneers, and solid wood accents.  No particle board, compressed paper, or vinyl veneers. 
http://charneyaudio.com/the-maestro.html