Please Recommend Highly Efficient Floor Standing Non-Horn Speaker Suggestions

Strictly speaking “highly efficient” means more than 100dB sensitivity, and there’s no way around that sans horns - indeed we’d be in all-horn territory here. If the 90-95dB sensitivity range will suffice - that is, it seems it must - that are some options. Have you considered Daedalus Audio?

Check out Reference 3A  i use their standmount speakers with my 4 watt tube amp Decware mini Torii and if it nice and loud in a 12 by 20 room

Flies under the radar as a Canadian company, but Verity Audio makes some of the best speakers I’ve ever heard and are also high efficiency. 

I have been very, very impressed with Ascend Acoustics Sierra Tower with RAAL tweeter. I plan to do a write up, soon, but these are my main speakers now. Their tweeters are really top notch; very clear without the harshness of other metal dome tweeters I’ve heard. They are not at the top of the speaker, and that, too, is a design plus. The bass is quite good but, more important for me, they mate extremely seamlessly with my subs.

Don't get bogged down with sensitivity specs, thought these are over 90db, effectively. More important, look at the impedance graphs -- barely dips below 5 ohms, if memory serves. I also have Salks, but they are stand mounts and harder to drive well.

Ascend is a great company to work with. They really know what they’re doing. Very responsive over email, phone. I am driving them with Quicksilver Mono 60wpc and even with KT77 tubes, they have plenty of get up and go. They sing with my Pass XA 25. At the $3k price point, I don’t think I could have found a better match for my gear.

Tekton, Zu, Devroe, Raven Audio CeLest, QLN Sonora,