Please Recommend Highly Efficient Floor Standing Non-Horn Speaker Suggestions

Listen to just rock and roll, loudly. Clarity and neutral definition with Impact. One system Tekton DI and other Focal aria 948's    enjoy

Running Horning Eufrodite (98db) with a 4.1 watt 2A3 Whammerdyne amp. Awesome. With your Mac amp, I would think that you could run about anything.

I heard the Apertura Edena, and they were much better than the Legacy Signature SE, to my ears. 
You might consider this Apertura speaker, too: 
https://apertura-audio.com/en/products/enigma-mkii/#specifications
Frequency range : 30-30 000Hz / +-3dB
Sensitivity : 95 dB/2.83v/1m
Impedance : 4 Ω

@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.