Keep fiddling with them. You will get it correct.
Beautiful job on the cabs BTW.
I believe Model 19 crossovers, or N1201-8A's would be a nice improvement. Too bad these seem to have gotten popular and gone way up in price.
Search the site and see if you might want to build your own.

BTW...I'm 55 and can't hear the extreem HF at low volumes either. So just crank em up!

Ron