Hales signature 2's.

I wouldn't mess with what the designer did unless someone very knowledgeable is involved....a professional like head of another big audio company.
These speakers are great the way they are. I've spent many hours listening to them (at a friend's). His system used a Muse 18 to reinforse the bottom, which had a custom board to integrate the two, designed buy Muse.
Again, I would avoid thinking you or a friend can improve on what a very successful designer presents to you.

Did the Muse sub help? How do you think this combo holds up today?

YES! As any excellent design, it holds up great but it may overpower you room.

I owned a pair for almost ten years. bought them new in 1990. absolutely loved them. wonderful fast and accurate mid bass. properly postioned, i got fantastic bass down to 40.

Doctor b wondering what you replaced them with? Why?
Must be pretty special, as they are hard to beat.