All I know is good quality mono recordings still sound like the performers are playing live in my room with my Ohm Walsh speaker setup. This setup has opened me up to so many older recordings that I would probably not pay much attention to otherwise. The best for bringing old mono recordings to life. Example: remastered Muddy Waters CD recordings originally from the 50s. He is there in the room. Not too shabby with stereo either. Coherency and carefully managed wide dispersion in the unique Ohm Walsh CLS design pays off!
https://photos.app.goo.gl/9mMf2dXS51F1oGH1A
https://photos.app.goo.gl/9mMf2dXS51F1oGH1A