They use SI baskets. The dimensions can be found there.
I've always cut my holes free-hand. I sometimes like doing things the hard way, probably cause my aspie autism. hehe!
That's why they aren't perfect circles if you look closely. But the end result is that I can make it any size or shape I want. You just gotta learn how to hold a router solidly and skillfully or it will run away and ruin the whole panel/box.
I free-handed all my SEOS cutouts too, I ain't got no CNC.
1 vs 1 is obvious, but I really don't understand how less could be more...
Do you have SPL and THD plots of both before and after?
Maybe you are hearing less distortion, thermal compression, transient response, dynamics, and air leakage around the drivers???
The charts shouldn't lie... if you are hearing a big improvement, it should be measurable.
It could just be all in your head... you've convinced yourself it sounds better, because they cost more and have better specs maybe...
Humans hear loudness as superior. Maybe they are just louder or more dynamic. It should be measurable!