Please Recommend Highly Efficient Floor Standing Non-Horn Speaker Suggestions

@headphonedreams 

I was going to suggest the same. I have a pair of F502SPs that I love. They are 92db, easy to drive and more than enough speaker even for my decent size room.

The reasoning is Physics. 

Hofmann's Iron Law

three parameters that cannot all be had at the same time. They are low-bass reproduction, small (enclosure) size, and high (output) sensitivity." Hofmann stated that designers could pick two of these three parameters, but in doing so, it would compromise the third parameter.

Also not a fan of horn tweeters. I love the Revel F328Be (25mm) beryllium tweeter driven by massive 85mm dual ceramic magnets). 3-Way Triple 8" Floorstanding Loudspeaker. I have their baby brother and upgraded to these. 

Search for them and you'll find scores of good reviews and happy customers. 

Tonian Labs

Another option: Sibelius by Pearl Acoustics. I have not heard them. They have reviews on the web, though. Just received via email from Harley at Pearl Acoustics (owner and maker of the Sibelius line): "I can absolutely assure you that the impedance of our drivers, in their enclosures is a true nominal 7,5ohms. The lowest it goes is about 7ohm at around 5hz. It rises and drops sharply around the resonant frequency at 38hz. And rises up to about 16ohm at around 20KHz.  But there is absolutely nothing to worry about here. The Sibelius is easy to drive and very forgiving for the amplifier, from this perspective.”

https://pearlacoustics.com/sibelius-sg/