Full Range, Open Baffle Project

[perceval]

The Qts is 0.57 which is better than most, but not ideal for OB (>0.7). It's a good value, but I am looking for state-of-the-art.

Qts is only one parameter. Plenty of other factors will affect a driver's response, and how it will be used.

Even low Qts drivers, with a healthy XMax, EQ and used in multiples can outperform the so-called high Qts needed for OB.
Plus, your OB will be subwoofer supported, so why limit yourself to high Qts drivers?