I haven’t seen discrete mention of the importance of driver surface area emphasized re: your intentions. Hints, but not the harsh reality check:
A 40 x 40’ room (am I recalling dimensions correctly?) is immense by hifi speaker standards. It will take an incredible second-hand deal, or a very decent PA kit deal, to fill suitably given that intense orchestra is your benchmark.
The DIY route was well-advised at your price point, even if perfection proves elusive 😉
https://audioroundtable.com/misc/nflawp.pdf