When you started to say that you had distortion/vibration with female vocals i was going to say that's just how some women sound...hahahaha. and it travels from left to right as they move around the room.
But seriously, I appreciate your story and solution. That's a good company there!!!! Especially to have drivers available from 30 years ago.
Next time you have the need to lug something up your stairs, call me, I'll help. But may be a beer or two involved.