Thanks , sub was intended as you said to sharpen up the SUB231-G.
The highest setting is 220 Hz on them, not 500, but they are
well integrated with the midrange driver.
The Acapella tweeter , despite having its own xover and volume control is a bit difficult to integrate, but to my ears sounds sweeter than the "normal" ones, some claim however that ozone ( which is constantly generated) + the strong electromagnetic field can be potentially harmful.
Don't believe sensitivity is such an issue, due to self amplification ( and own volume control).
I'm using above concoction in one of my systems, the main one is still having 5 Permandur ALE drivers, including a quad P160 for the 50' long straight bass horns.
Now we can talk crossover quality to integrate them and time alignment ( like in Haas) of the bass , sadly there is no Jim Smith in Europe :-)
I know there is always a degree of subjectivity, but I like the Avantgarde Solo as well, as well as the DUO for its musical midrange, more than the TRIO that I also have ( with metal membrane), maybe the latter was not optimally set-up, who knows.
Enjoy the music and the weekend,
Dan